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What is Astronomy? Definition & History | Space

Humans have long gazed toward the heavens, searching to put meaning and order to the universe around them. Although the movement of constellations patterns imprinted on the night sky were the easiest to track, other celestial events such as eclipses and the motion of planets were also charted and predicted.

Definition of astronomy: Astronomy is the study of the sun, moon, stars, planets, comets, gas, galaxies, gas, dust and other non-Earthly bodies and phenomena. In curriculum for K-4 students, NASA defines astronomy as simple "the study of stars, planets and space." Astronomy and astrology were historically associated, but astrology is not a science and is no longer recognized as having anything to do with astronomy. Below we discuss the history of astronomy and related fields of study, including cosmology.

Historically, astronomy has focused on observations of heavenly bodies. It is a close cousin to astrophysics. Succinctly put, astrophysics involves the study of the physics of astronomy and concentrates on the behavior, properties and motion of objects out there. However, modern astronomy includes many elements of the motions and characteristics of these bodies, and the two terms are often used interchangeably today.

Modern astronomers tend to fall into two fields: the theoretical and the observational.

Unlike most other fields of science, astronomers are unable to observe a system entirely from birth to death; the lifetime of worlds, stars, and galaxies span millions to billions of years. Instead, astronomers must rely on snapshots of bodies in various stages of evolution to determine how they formed, evolved and died. Thus, theoretical and observational astronomy tend to blend together, as theoretical scientists use the information actually collected to create simulations, while the observations serve to confirm the models or to indicate the need for tweaking them.

Astronomy is broken down into a number of subfields, allowing scientists to specialize in particular objects and phenomena.

Planetary astronomers (also called planetary scientists) focus on the growth, evolution, and death of planets. While most study the worlds inside the solar system, some use the growing body of evidence about planets around other stars to hypothesize what they might be like. According to the University College London, planetary science "is a cross-discipline field including aspects of astronomy, atmospheric science, geology, space physics, biology and chemistry."

Stellar astronomers turn their eyes to the stars, including the black holes, nebulae, white dwarfs and supernova that survive stellar deaths. The University of California, Los Angeles, says, "The focus of stellar astronomy is on the physical and chemical processes that occur in the universe."

Solar astronomers spend their time analyzing a single star our sun. According to NASA, "The quantity and quality of light from the sun varies on time scales from milli-seconds to billions of years." Understanding those changes can help scientists recognize how Earth is affected. The sun also helps us to understand how other stars work, as it is the only star close enough to reveal details about its surface.

Galactic astronomers study our galaxy, the Milky Way, while extragalactic astronomers peer outside of it to determine how these collections of stars form, change, and die. The University of Wisconsin-Madison says, "Establishing patterns in the distribution, composition, and physical conditions of stars and gas traces the history of our evolving home galaxy."

Cosmologists focus on the universe in its entirety, from its violent birth in the Big Bang to its present evolution, all the way to its eventual death. Astronomy is often (not always) about very concrete, observable things, whereas cosmology typically involves large-scale properties of the universe and esoteric, invisible and sometimes purely theoretical things like string theory, dark matter and dark energy, and the notion of multiple universes.

Astronomical observers rely on different wavelengths of the electromagnetic spectrum (from radio waves to visible light and on up to X-rays and gamma-rays) to study the wide span of objects in the universe. The first telescopes focused on simple optical studies of what could be seen with the naked eye, and many telescopes continue that today. [Celestial Photos: Hubble Space Telescope's Latest Cosmic Views]

But as light waves become more or less energetic, they move faster or slower. Different telescopes are necessary to study the various wavelengths. More energetic radiation, with shorter wavelengths, appears in the form of ultraviolet, X-ray, and gamma-ray wavelengths, while less energetic objects emit longer-wavelength infrared and radio waves.

Astrometry, the most ancient branch of astronomy, is the measure of the sun, moon and planets. The precise calculations of these motions allows astronomers in other fields to model the birth and evolution of planets and stars, and to predict events such as eclipses meteor showers, and the appearance of comets. According to the Planetary Society, "Astrometry is the oldest method used to detect extrasolar planets," though it remains a difficult process.

Early astronomers noticed patterns in the sky and attempted to organize them in order to track and predict their motion. Known as constellations, these patterns helped people of the past to measure the seasons. The movement of the stars and other heavenly bodies was tracked around the world, but was prevalent in China, Egypt, Greece, Mesopotamia, Central America and India.

The image of an astronomer is a lone soul at a telescope during all hours of the night. In reality, most hard-core astronomy today is done with observations made at remote telescopes on the ground or in space that are controlled by computers, with astronomers studying computer-generated data and images.

Since the advent of photography, and particularly digital photography, astronomers have provided amazing pictures of space that not only inform science but enthrall the public. [All-Time Great Galaxy Photos]

Astronomers and spaceflight programs also contribute to the study of our own planet, when missions primed at looking outward (or travelling to the moon and beyond) look back and snap great pictures of Earth from space.

Follow Nola Taylor Redd at @NolaTRedd, Facebook, or Google+. Follow us at @Spacedotcom, Facebook or Google+.

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What is Astronomy? Definition & History | Space

The Thirty Meter Telescope: How a volcano in Hawaii became a battleground for astronomy – Space.com

MAUNAKEA, Hawaii The sun pointed to a little before noon when a chorus of conch shells and bamboo flutes trumpeted into the sharp mountainside breezes. The noise marked the start of a religious ceremony and a demonstration against construction of a massive telescope on what some consider sacred land. The participants saluted east, toward the distant ocean; then south, toward the volcanic shell of a past eruption; then west; then north, toward the summit where a dozen telescopes loomed far out of sight.

Many of the people taking part in that ceremony, halfway up the mountain of Maunakea at the heart of Hawaii's Big Island, were native Hawaiians who call themselves kia'i (pronounced kee AH ee), or protectors. By that, they mean protectors of the mountain itself, from the construction of the Thirty Meter Telescope (TMT) at its summit, where the facility would join venerable observatories like the twin Keck domes and NASA's Infrared Telescope Facility.

I visited the kia'i encampment on the last day of 2019 and the 172nd day of the continuing vigil against construction. Nearby was an octagonal road sign edited to read "Kia'i STOP TMT." Less than two weeks before, with the mountain's harsh winter looming, law enforcement had left the spot. The retreat marked an acknowledgement of a stalemate that began nearly a decade ago and stretches from the ocean to the stars, but is expected to shift once again as spring returns.

(Outside events have already prompted a shift in the situation. In response to the spread of the novel coronavirus that is causing the serious respiratory disease COVID-19, the kia'i have asked visitors to stay away from their previously welcoming encampment, according to a statement released on March 14.)

For the kia'i, the 160-foot-tall TMT (49 meters) would be one telescope too many at a site they see as stolen, sacred, delicate and consistently mismanaged. "It's too big, too massive, and it's in the wrong place," E. Kalani Flores, a professor of Hawaiian studies at Hawaii Community College and one of the lead plaintiffs in court cases surrounding the construction of the Thirty Meter Telescope, told Space.com. "There's a certain tipping point and the TMT would exceed that tipping point."

That's why a subset of native Hawaiians have said no to TMT, in words and actions, for years. Some are calling the current situation an existential crisis for astronomy and for Hawaii. It's certainly a crisis of communication for astronomers who support the project. And while some of the tension reflects Hawaii's history of colonization and oppression, some of the main sticking points display remarkable irony given the telescope's priorities.

Related: Controversy over giant telescope roils astronomy conference in HawaiiMore: Thirty Meter Telescope: Hawaii's giant space eye in pictures

The saga of the TMT began in 2003, when a nonprofit partnership formed between two universities in California and counterparts in Japan, China, India and Canada. Now called TMT International Observatory, the group set out to design a telescope with such a massive observing mirror that it would change science forever. Its findings could tackle some of astronomy's signature existential questions, Gordon Squires, TMT's vice president for external relations and an astronomer by profession, told Space.com: Are we alone? How did the universe wake up? What is dark matter?

Squires said he believes that the process of answering those questions, and the answers themselves, could change humanity forever; that's why he became an astronomer in the first place. "If the world saw the universe the way I do, or the way we do, the world would be a fundamentally different place," he said. "I still believe that."

In 2009, the TMT set its sights on the summit of Maunakea; since then, it has worked to negotiate access and construction with the state, which owns the land, and the University of Hawaii, which manages the astronomy precinct.

It has not gone smoothly.

Flores and other native Hawaiians have filed multiple court cases over the permits required for construction. When the TMT tried to break ground in 2014, the kia'i interrupted the ceremony. Tensions came to a head in July 2019, when the TMT announced it was ready to try building again and the kia'i mobilized, blocking construction trucks from the road that climbs to the summit. They settled in with tents and Porta-Potties, a kitchen and a makeshift university offering lessons in native history and culture.

(By then, the TMT had spent $500 million in 2014 dollars worldwide on the project; current estimates suggest it will total about $2.4 billion in today's dollars, although that number will change based on where and when construction finally begins, a TMT representative said.)

Related: The biggest telescopes on Earth

Each morning, the kia'i greet the sun; three times a day, they conduct a ceremony called the 'aha, or the protocol, a series of chants and dances representing their beliefs about the mountain and lasting an hour or longer. It's that protocol the kia'i began by greeting the cardinal directions, barefoot and clad in street clothes. Early in the ceremony, they called on their ancestors. "Grant us insight, grant us power," one chant reads in a translation posted to the kia'i's website.

For centuries, kia'i told me, those ancestors have come to the mountain and, more frequently, worshipped it from afar. The tenuous atmosphere at the summit, 13,000 feet (4,000 meters) above sea level, leaves little oxygen to feed a human brain. For native Hawaiians, that shortage is a sign that the summit is the realm of deities and that humans should visit only for specific purposes.

That's why Noelani Goodyear-Kaopua, a native Hawaiian and a political scientist at the University of Hawaii at Manoa, has only ever been to the summit once, 10 years ago. Ever since, she has remembered what breathing the thin atmosphere felt like, she told Space.com. "The line between living and dead, or here and the next realm or the realm of the ancestors or however you want to think about that, was much more porous because you are so much out of the realm of where humans are normally supposed to be."

But devotion at a distance has complicated matters for the Hawaiians who wish to see the mountain protected: Because a key piece of their religious practice lies in leaving the summit alone, they've struggled to convince authorities that the land is important to them or that they should have a say in what happens to it.

That said, the kia'i can point to a ring of hundreds of shrines about 1,000 feet below the summit, which they say mark the edge of the most sacred zone. These shrines are nothing dramatic, Flores said: standing stones a foot or two tall, reaching the height of a kneecap, some toppled by time. But TMT construction would run right through that ring, he said, and that shouldn't be acceptable.

(Squires contends that TMT selected its location in consultation with native Hawaiians to avoid areas of concern. "It's on a site that has no historically significant or cultural practice areas on it," he said, citing the nearest cultural site as being a mile away.)

Related: World's largest reflecting telescopes explained (infographic)

In a controversy that is often framed as a conflict between science and religion, despite native Hawaiians pointing to their long history of studying the stars, the shrines point to the first key irony underlying the TMT controversy. Many of the standing stones mark points on the horizon where particularly meaningful stars rose, set or reached their zenith, according to Flores.

"There's hundreds of shrines around, and some of these shrines are interconnected together and then they build a star grid," Flores said. "What you see in the heavens is what you see on Earth."

Hawaii's rich tradition of skywatching is hardly the extent of Maunakea's sacredness, however. Down the slope, as the noontime ceremony continues, the kia'i sing of the creation of what they call Mauna a Wakea, from the union of Wakea the Skyfather and Papa the Earthmother. Native Hawaiians tie their own origin story to that of the mountain.

"We have always revered Maunakea as our sacred mauna," Noe Noe Wong-Wilson, a leader of the kia'i, told Space.com. "In fact, it is part of our cosmology, the very beginning of Earth from which man descends, so for us it's a very spiritual matter."

That's the second irony of the controversy surrounding the TMT, which is tailored to elucidate astronomy's own vision of cosmology.

"Astronomers oftentimes think that an interest in the universe and our origins in the universe is what unites all cultures," Sara Kahanamoku, a native Hawaiian and a doctoral student in marine ecology at the University of California, Berkeley, told Space.com. "But [they] maybe don't realize that some cultures don't necessarily need to explore the universe to know where we come from."

Kahanamoku is the lead author of one of a collection of native-led white papers exploring the ways astronomy in Hawaii affects non-astronomers. The group submitted the papers as public comments to the government's decadal survey of astrophysics, which sets scientific priorities for the field. She and her co-authors offer a collection of recommendations for dealing with situations like the TMT, including establishing a system paralleling the institutional review boards that oversee research done on humans.

"We really believe that good science also means that you also need to be good to the people that you're working among," Kahanamoku said.

Related: Hawaii night sky revealed in stunning new video

Of course, some Hawaiian residents and native Hawaiians alike support the TMT, seeing the telescopes atop Maunakea as modern successors to the islanders' pre-contact expertise at navigating by the stars, as a vital segment of the local economy, and as a pathway to educational and employment opportunities for their children.

(A TMT representative said that it's too early to estimate how much would be spent in Hawaii if the project goes through, but that once the facility is observing, the organization expects to spend about $50 million each year on operations and employ 140 people.)

Tyler Trent, a doctoral student in astronomy at the University of Arizona, is one of those native Hawaiians, although he said he wrestled with the decision. "Whether I'm for it or against it, if that gets built, people are going to be hurt by it," he told Space.com.

Trent concluded that TMT and its counterparts deserve a place on the sacred summit. "I don't see them as like another shopping center or another hotel," he said. "These are special things that are illuminating secrets of the universe." He worries that continuing opposition to the TMT is painting his culture as backward and anti-science, despite the loud objections of kia'i that they are no such thing, and he's disappointed that some astronomers unaffiliated with the project have started speaking out against construction on Maunakea.

"Maybe astronomers taking too neutral of a stance or even supporting the kia'i because that's what they believe being respectful to native Hawaiian culture is I'm starting to think that maybe that's not the right way to go about it," he said. "I think at the end of the day, it's people from the outside picking which native Hawaiian culture they want to support or they want to agree with. I think that if outsiders want to pick one, I truly think that they should support the side that is trying to integrate the two, that is trying to build bridges between the two."

Trent added that he thought he would feel the same way if the site were on his own island, Oahu, which holds Honolulu. But it can't be. For scientists hoping to build the TMT, the summit of Maunakea is simply the best possible site. They want a Northern Hemisphere location to better facilitate partnerships with telescopes in the south, including the equally massive Giant Magellan Telescope already under construction in Chile.

Then, it's a matter of atmospheres. It's here that Maunakea really shines, although you wouldn't know that halfway to the summit, where the kia'i camp amid gusts of wind and transitory bursts of showers and sun.

It's a different story at the summit itself, which picky astronomers consider among the best places on Earth for ground-based astronomy. That's in part because of, ironically, one of the same reasons native Hawaiians consider the peak sacred: the barely-there oxygen. Like so many telescopes around the world, TMT has gravitated to a mountaintop site that would carry its optical equipment through some of the lower layers of Earth's atmosphere, which can blur telescope images.

Even the summit's view, however, leaves astronomers dissatisfied. That's why TMT would be armed with an adaptive optics system, which measures and automatically subtracts blurriness caused by the atmosphere. TMT's version would be equipped with lasers that create artificial stars for the system to judge, which lets astronomers observe fainter objects.

But such technology doesn't negate astronomers' desire to remain perched at high elevations, TMT project scientist Christophe Dumas told Space.com. For a project as ambitious as TMT, he said, siting is crucial to an instrument's output, despite opposition. The TMT has its eye on a site in the Canary Islands as a back-up location, which would slightly reduce the project's price tag, a representative said. But that site is still a clear second choice for astronomers and would require some adjustments to the facility, he said.

For the kia'i, their opposition is not just about Maunakea, it's about the way astronomy and science in general operates, particularly given that mountaintops are nearly always sacred to someone. One leader of the kia'i emphasized that the solution was not merely for the TMT to move, as some astronomers have begun to call for, but to find a location where people truly welcome it.

That could require a new way of approaching such projects, several native Hawaiians said. In particular, scientists looking to start a new project would be wise to incorporate local communities in discussions long before any opposition begins long before it's even a project, in fact.

'Imiloa Astronomy Center, which operates under the aegis of the University of Hawaii at Hilo and seeks to tell all the various stories of Maunakea, is working to foster these conversations at Maunakea and elsewhere. Such dialogues should begin earlier and without such tense motivation, Ka'iu Kimura, a native Hawaiian and 'Imiloa's director, told Space.com. "Not because there's conflict, but because it's just the right thing to do," she said.

The astronomy precinct at Maunakea and the TMT specifically are far, far past that point. Construction on the first modern telescope at the site began in 1964, and over the intervening decades, plenty of hard feelings have built up.

TMT isn't the first Maunakea project to meet opposition, but supporters and kia'i alike told me that things seem to be different this time. "I think a lot of people are saying, we have stood by long enough," Goodyear-Kaopua said. "The narrative that's been put forward is, well, why can't Hawaiians just share? We have been sharing for a long time, not always at our consent." She wants to see more native Hawaiians involved in making decisions about the summit.

One of the most significant decisions about the summit was made in the fall of 2018, when a state Supreme Court ruling allowed the project to continue. Four justices agreed with the state land management board's argument that astronomy had already changed the summit so much that one more observatory couldn't really make a difference. One dissented, arguing that this so-called degradation principle set a dangerous precedent.

For the kia'i, who see the mountain as a relative as much as a resource, "one more can't hurt" is not an acceptable philosophy. Many of the native Hawaiians I spoke with pointed to the degradation principle to voice their concerns about how decisions are made not just at Maunakea, but around the world. Some referenced climate change, others focused on land use, but many expressed concern about how humans have exploited and continue to exploit the planet.

Related: European scientists are taking a mock moon mission in Hawaii right now

Toward the end of the protocol, the ceremony leader explained that the next dance was a new addition to the daily ceremony. It traced water on its journey throughout the island and the water cycle, they said: from ocean to clouds to rain to waterfalls to ponds to rivers to cultivated fields to estuaries to ocean, with plenty of stops in between.

It's that same connected water that the kia'i mentioned again and again in their concerns about the TMT. It's another irony in the controversy: Among other discoveries, the TMT could help astronomers identify planets with water in their atmospheres, a first step toward finding a habitable world. But the kia'i already know of one very habitable planet with that precious liquid in its atmosphere, and they consider it their responsibility to protect that water and the mountain that anchors it to the Big Island.

(It was while watching this dance that I was struck by how closely the protocol seemed to parallel the kia'i concerns about the telescope; I've structured this story to follow the protocol as a mark of gratitude for the ceremony leader's work to make that connection.)

"Water is a sacred thing for all of humanity," Kealoha Pisciotta, a native Hawaiian who was a technician at two telescopes on Maunakea before deciding she couldn't condone the way the observatories treat the summit, told Space.com. "We use it ceremonially as well; the snow, ice and water from Maunakea is collected for ceremony."

One of Pisciotta's concerns about astronomy at Maunakea has been the observatories' treatment of the water. She said that during her time working on the summit, she saw spills of hazardous substances from bug spray to mercury, and that she has seen evidence of only one existing observatory addressing those issues.

It's one of the most common concerns I heard about TMT as well, that it could contaminate water across the island. The TMT's response is that those concerns are completely unfounded. There's no evidence the observatory could affect the water, the TMT says; the nearest wells are about 12 miles away; the observatory won't rely on mercury, the worst of the chemicals used to clean telescope mirrors; the facility has a system to transport wastewater from science operations and human staff support alike off the mountain.

But still, the kia'i say, they worry about the water. The summit is a particularly sensitive place in the eyes of native Hawaiians because it's where water first touches land. "It's in its purest form, unaltered by humans, unaltered by any other aspects," Flores said of the rain, snow and fog at the summit, which makes interfering with it particularly dire. "You disrupt, disturb, desecrate the water in its highest forms, and [the elders] tell us the water is the basic form of life for all of us on this planet."

And while the kia'i agree that the hydrology models of Hawaii to date show that TMT shouldn't contaminate anything, that isn't a satisfactory response for them. "I think regardless of that, because the models are not clear, there's still a possibility that there could be infiltration because it's very complex," Rosie Alegado, a native Hawaiian and an oceanographer at University of Hawaii at Manoa, told Space.com. "The models that we have are definitely incomplete."

For Stephanie Malin, an environmental sociologist at Colorado State University, that situation is not surprising. Development projects typically rely on technocratic assessment of potential risks, she said, while indigenous groups tend to exercise a precautionary principle that delays development until there is certainty that there are no risks which isn't always possible.

"I don't necessarily think that the two groups are talking the same language, even," Malin told Space.com.

Related: How space exploration can teach us to preserve all life on Earth

Near the end of the noontime ceremony, the gathered kia'i completed a series of dances open to all, regardless of their knowledge of hula. The only requirement, the ceremony leader explained, was that participants dance with the intention of stopping TMT from being constructed on Maunakea. And so the kia'i hold space at the mountain and dance three times a day, to protect the mountain that tells them their place in the universe. Later, they progressed toward the summit, taking one step at a time, dodging the tents around the dance space.

It's not clear what the TMT's steps forward might be. If the TMT decides the Maunakea site is no longer worth the pain, as the kia'i hope, they will take their plans to the Canary Islands. It's unclear how much longer they are willing to wait to begin construction which is scheduled to last 10 years in earnest.

A sharper deadline is also looming over Maunakea: the master lease agreement between the state and the University of Hawaii, which governs every observatory's sublease, will expire in 2033. What negotiations might look like is still unclear, but chances are they won't resemble the process that led to the original agreement decades ago. The master lease worries all the observatories on the summit, but particularly TMT, which dreads reaching first light just in time for site access to fall apart entirely.

Even the most strident opponents of TMT aren't calling for all the telescopes to be removed. They do, however, want the observatories to be better neighbors, more responsive to local concerns and more respectful of the land from which they study the stars.

No one thinks that will be straightforward. For the astronomers affiliated with the TMT project, the conversations of the past decade have already challenged their perceptions of their own values. "We never thought we were the bad people, and some people think authentically that we are," Squires said.

The kia'i I spoke with never phrased their feelings quite like that. Many insisted they aren't trying to stop science: Instead, they're trying to improve it.

"Science that doesn't empower humanity for a better Earth is maybe not the science we need to be doing," Pisciotta, the former telescope technician who once dreamed of studying cosmology and who described her family as traditional star people, said. That's perhaps especially true of astronomy, she added, since astronomers cannot escape the way distance acts as a time machine across the universe.

"Everything in astronomy is looking back in time," she said. "It has to find its modern relevancy. Yes, it's noble, but we can make it more noble together, though."

Email Meghan Bartels at mbartels@space.com or follow her @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.

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The Thirty Meter Telescope: How a volcano in Hawaii became a battleground for astronomy - Space.com

Slooh will livestream astronomy lesson for K-12 students during coronavirus outbreak – Space.com

Slooh astronomers will livestream a free astronomy lesson for K-12 students who are homebound during the coronavirus pandemic.

On Thursday (March 19), Slooh will livestream a free, 1-hour astronomy lesson and live telescope views from around the world. The webcast, which is geared toward K-12 students, will begin at 4:30 p.m. EDT (2030 GMT). You can watch it live on Slooh's YouTube channel, or stream it here on Space.com, courtesy of Slooh.

"Slooh is committed to bringing out the very best in students and all people," Russell Glenn, director of education for Slooh, said in an emailed statement. "We believe that space education is crucial in understanding and gaining perspective on the world around us."

Related: Free space projects for kids (and adults) stuck at home during the coronavirus outbreak

During the webcast, Glenn and Slooh astronomer Paul Cox will walk viewers through one of Slooh's starter quests, called Cosmic Explorer, which introduces students to the Slooh interface and offers a basic lesson on the sun, moon, galaxies, and the birth and death of stars. This livestream will also provide views of objects that are visible in the night sky.

"We want to help people to share in the wonder of space together as a community so that we can recognize our shared humanity," Glenn said. "We will be bringing as much content as possible during this challenging time. We see this great challenge as a great opportunity for students to own their learning and get excited about space."

The webcast will also provide views of space from Slooh's 10 online telescopes, including those situated at the Institute of Astrophysics of the Canary Islands, which makes daytime astronomy possible for students in the United States, Slooh officials said in a statement.

In addition to this free astronomy lesson, Slooh offers several paid membership options for students, teachers and parents to learn about space while they are homebound. Slooh community members can control Slooh's telescopes online, schedule missions, and select and work on different educational activities, called quests.

"When their mission is active, they can be observing and capturing images in real time," Glenn said in the email to Space.com. "Additionally, students can observe other missions planned by other members of the Slooh community and capture images of the objects that they are viewing."

Slooh also offers astronomy clubs for educators to engage students and citizens from home and explore space together via a network of online telescopes. This includes remote learning activities and support from Slooh's astronomy educators.

Follow Samantha Mathewson @Sam_Ashley13. Follow us on Twitter @Spacedotcom and on Facebook.

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Slooh will livestream astronomy lesson for K-12 students during coronavirus outbreak - Space.com

The Sky This Week from March 20 to 27 – Astronomy Magazine

Friday, March 20Its officially spring in the Northern Hemisphere. To celebrate, Mars and Jupiter meet up in the morning sky in the first of two planetary conjunctions this month. Look for the glittering stars of Sagittarius the Archer in the southeast in the two hours or so before sunrise. There, magnitude 0.9 Mars is a mere 0.7 south of magnitude 2.1 Jupiter.

About 7 east of Jupiter, magnitude 0.7 Saturn waits its turn for a close-up with the Red Planet. Mars will soon tango with the ringed world, coming closest on March 31.

Saturday, March 21Today is the perfect day to seek out our solar systems speediest planet. The Moon passes 4 south of Mercury at 2 P.M. EDT, but youll want to catch the pair in the morning before sunrise. At that time, the two will stand 5 apart, with Mercury glowing at magnitude 0.2 in the east-southeast 30 minutes before the Sun crosses the horizon.

Saturday is also Galactic Tick Day. The holiday is celebrated every 633.7 days (1.7361 years) to mark one galactic tick, which represents 1/100 of an arcseconds worth of the orbit our Sun and solar system make around the Milky Way. (It takes 225 million years to complete a full orbit.) You can learn more about the origins of this quirky and humbling holiday on the Galactic Tick Day homepage.

In honor of our journey through the galaxy, step outside from a dark site to see if you can spot the Milky Way running overhead. The plane of our galaxy runs through Cygnus the Swan, setting in the northwest as the sky grows darker after sunset. In the east, Orion the Hunter rises with the Milky Way at his right shoulder, which is marked by the bright red star Betelgeuse.

Sunday, March 22The fast-fading Moon is just 3 percent lit and rises shortly before the Sun, making tonight an excellent night to search out some of the skys fainter objects. Consider trying for M81 and M82, also known as Bodes Galaxy and the Cigar Galaxy, respectively. Both in the constellation of Ursa Major, these two galaxies appear only 37' apart on the sky and are easy to catch in the same field of view through binoculars or a telescope at low magnification. M81 has an active supermassive black hole in its center, while M82 is undergoing a massive burst of star formation hence its classification as a starburst galaxy. Astronomers believe this flurry of activity was actually caused by gravitational interactions with M81. Through a scope, M82 appears long and thin like a cigar while M81 has a rounder shape.

Monday, March 23Mercury reaches greatest western elongation (28) at 10 P.M. EDT, several hours before it rises ahead of the Sun. At sunrise, the tiny magnitude 0.3 planet is 10 above the horizon in the east-southeast, and its 7"-wide disk is just over half lit.

Today also marks the 180th anniversary of the first photograph ever taken of the Full Moon. John Draper captured the daguerreotype on this date from his observatory in New York after several previous attempts.

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The Sky This Week from March 20 to 27 - Astronomy Magazine

Astronomers have found the edge of the Milky Way at last – Science News

Our galaxy is a whole lot bigger than it looks. New work finds that the Milky Way stretches nearly 2 million light-years across, more than 15 times wider than its luminous spiral disk. The number could lead to a better estimate of how massive the galaxy is and how many other galaxies orbit it.

Astronomers have long known that the brightest part of the Milky Way, the pancake-shaped disk of stars that houses the sun, is some 120,000 light-years across (SN: 8/1/19). Beyond this stellar disk is a disk of gas. A vast halo of dark matter, presumably full of invisible particles, engulfs both disks and stretches far beyond them (SN: 10/25/16). But because the dark halo emits no light, its diameter is hard to measure.

Now, Alis Deason, an astrophysicist at Durham University in England, and her colleagues have used nearby galaxies to locate the Milky Ways edge. The precise diameter is 1.9 million light-years, give or take 0.4 million light-years, the team reports February 21 in a paper posted at arXiv.org.

To put that size into perspective, imagine a map in which the distance between the sun and the Earth is just one inch. If the Milky Ways heart were at the center of the Earth, the galaxys edge would be four times farther away than the moon actually is.

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To find the Milky Ways edge, Deasons team conducted computer simulations of how giant galaxies like the Milky Way form. In particular, the scientists sought cases where two giant galaxies arose side by side, like the Milky Way and Andromeda, our nearest giant neighbor, because each galaxys gravity tugs on the other (SN: 5/12/15). The simulations showed that just beyond the edge of a giant galaxys dark halo, the velocities of small nearby galaxies drop sharply (SN: 3/11/15).

Using existing telescope observations, Deason and her colleagues found a similar plunge in the speeds of small galaxies near the Milky Way. This occurred at a distance of about 950,000 light-years from the Milky Ways center, marking the galaxys edge, the scientists say. The edge is 35 times farther from the galactic center than the sun is.

Although dark matter makes up most of the Milky Ways mass, the simulations reveal that stars should also exist at these far-out distances. Both have a well-defined edge, Deason says. The edge of the stars is very sharp, almost like the stars just stop at a particular radius.

In the future, astronomers can refine the location of the Milky Ways edge by discovering additional small galaxies nearby. Astronomers could also search for individual stars out at the boundary, says Mike Boylan-Kolchin, an astrophysicist at the University of Texas at Austin who was not involved with the study. The farthest such stars will be very dim, but future observations should be able to find them.

The measurement should also help astronomers tease out other galactic properties. For instance, the larger the Milky Way, the more massive it is and the more galaxies there should be revolving around it, says Rosemary Wyse, an astronomer at Johns Hopkins University who was not part of the new work. So far, there are about 60 known Milky Way satellites, but astronomers suspect that many more await discovery.

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Astronomers have found the edge of the Milky Way at last - Science News

We All Live In A Croissant-Shaped Giant Bubble, Say Astronomers – Forbes

Is this what the heliosphere looks like? New research suggests so. The size and shape of the ... [+] magnetic "force field" that protects our solar system from deadly cosmic rays has long been debated by astrophysicists.

Physicistshave revealed a refined new model of the heliospherethe vast region around the Sun extending more than twice as far as Plutothat depicts it as a crescent-shaped magnetic force-field resembling a freshly baked croissant.

Its the region of space that the Sun commands; its sphere of influence. Its the extent of the solar windcharged particles spewed-out by the Sunthat extends far past the orbits of the planets, creating a bubble around the Sun that accompanies it in its journey through interstellar space. At the edges of the heliosphere is where the solar wind meets the interstellar wind. It casts a magnetic force field around all the planets, deflecting charged particles that would otherwise get into the solar system ... and destroy DNA.

Thats controversial. Until recently, the consensus was that the shape of the heliosphere is comet-like. Its long been thought that the heliosphere stretches behind the solar system, creating a comet-like shapewith a round nose on one side and a long tail extending in the opposite direction. However, its also been described as a beachball-shape. However, according to Merav Opher, professor of astronomy and researcher at Boston UniversitysCenter for Space Physics, and her coauthor James Drake of the University of Maryland, the helio-sphere should really now be called the helio-crescent.

This graphic shows the position of NASA's Voyager 1 and Voyager 2 probes, outside of the ... [+] heliosphere, a protective bubble created by the Sun that extends well past the orbit of Pluto.

Opher and Drakes original paper in 2015 used data from NASAs Voyager 1 spacecraft, which crossed the boundary from heliosphere to interstellar space in May 2012. They identified two giant jets of material shooting backwards over the north and south poles of the Sun that curve around in two relatively short tails toward the back; a heliosphere that looks a lot more like a crescent moon than a comet.

A new simulation of the heliosphere the magnetic bubble surrounding the sun shows it to have two ... [+] relatively short jets streaming away from the nose.

Opher and Drakes research was controversial. It was very contentious, she says. I was getting bashed at every conference! But I stuck to my guns. However, in 2017 another model was proposed by scientists working on NASAs Cassini mission at Saturn. It stated that the heliosphere is much more compact and rounded than previously thoughtsomething like a beach ball.

Many other stars show tails that trail behind them like a comets tail, supporting the idea that our ... [+] solar system has one too. However, new evidence from NASAs Cassini, Voyager and Interstellar Boundary Explorer missions suggest that the trailing end of our solar system may not be stretched out in a long tail. From top left and going counter clockwise, the stars shown are LLOrionis, BZ Cam and Mira.

Its Opher and Drakes refined theory, with colleagues Avi Loeb of Harvard University and Gabor Toth of the University of Michiganoutlined in a new paper published in Nature Astronomythat two jets extend downstream from the nose rather than a single fade-away tail. Their new 3D model of the heliospheredeveloped on NASAs Pleiades supercomputer and supported by NASA and by the Breakthrough Prize Foundationreconciles their croissant model with the beach ball model. It does so by distinguishing between the solar wind and incoming neutral particles that drift into the solar system; the latter get much hotter so have an outsized influence on the shape of the heliosphere. However, there is still uncertainty; it depends on exactly how you define the edge of the heliosphere.

This artists impression shows the view from the surface of one of the planets in the TRAPPIST-1 ... [+] system.

The solar wind and the heliosphere could be key ingredients in the recipe for life in the Milky Way and beyond. "If we want to understand our environment we'd better understand all the way through this heliosphere," says Loeb, Opher's collaborator. Researchers studying exoplanets are keen to compare the Suns heliosphere with those around other stars. Theres also the DNA-shredding interstellar particles, which actually could have helped drive the genetic mutations that led to life like us, says Loeb. "At the right amount, they introduce changes, mutations that allow an organism to evolve and become more complex," he says. "There is always a delicate balance when dealing with life as we know it. Too much of a good thing is a bad thing," says Loeb.

Starting in the early 2030s, the Interstellar Probe would exit the solar system.

We need to explore the sea of space between our Sun and other potentially habitable systems. For now, all we have are the fading 40 year old science instruments on Voyager 1 and Voyager 2. Cue plans for the Interstellar Probe, a spacecraft that could launch in the 2030s and go farther and faster than any spacecraft before it to help us understand our home in the galaxy. It would start exploring the edge of the heliosphere 10 or 15 years after that. With the Interstellar Probe we hope to solve at least some of the innumerous mysteries that Voyagers started uncovering, says Opher.

Wishing you clear skies and wide eyes.

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Astronomers test string theory using NASA’s Chandra X-ray space telescope – Space.com

Astronomers have probed the Perseus galaxy cluster in search of an (so far) undetected particle that would help to support string theory.

String theory is the idea that all known forces, particles and interactions can be connected through a single framework to understand the physical universe. A team of astronomers using NASA's Chandra X-ray Observatory studied galaxy clusters the largest structures in the universe held together by gravity for signs of an ultra-low-mass particle called an axion, which many models of string theory predict should exist.

"While it may sound like a long shot to look for tiny particles like axions in gigantic structures like galaxy clusters, they are actually great places to look," David Marsh, co-author of the study from Stockholm University in Sweden, said in a statement from the Chandra X-ray Observatory.

Related: 7 surprising things about the universe

Axion particles are believed to have incredibly low masses, potentially ranging from a millionth of the mass of an electron down to zero mass. The team also looked for signs of "axion-like particles," which are a broader class of ultra-low-mass particles with similar properties to axions, according to the statement.

Additionally, these ultra-low-mass particles may sometimes convert into photons the particles that make up light when they pass through magnetic fields. In turn, photons may also convert into axions under certain conditions. Both scenarios depend on the mass of the particles and how easily they can make the conversion, also known as convertibility, according to the statement.

As part of this new study, astronomers using the Chandra space telescope studied the spectrum of X-ray emissions produced by material falling towards the supermassive black hole at the center of the Perseus galaxy cluster.

"Galaxy clusters contain magnetic fields over giant distances, and they also often contain bright X-ray sources," Marsh said in the statement. "Together these properties enhance the chances that conversion of axion-like particles would be detectable."

However, the team did not detect any distortions in the X-ray emissions that would indicate axion-like particles were present, according to the statement.

"Our research doesn't rule out the existence of these particles, but it definitely doesn't help their case," Helen Russell, co-author of the study from the University of Nottingham in the UK, said in the statement. "These constraints dig into the range of properties suggested by string theory, and may help string theorists weed their theories."

One possible explanation for these recent observations is that the particles have either a lower or higher convertibility than the Chandra space telescope is able to detect, the researchers said.

"Until recently I had no idea just how much X-ray astronomers bring to the table when it comes to string theory, but we could play a major role," Christopher Reynolds, lead author of the study from the University of Cambridge in the United Kingdom, said in the statement. "If these particles are eventually detected it would change physics forever."

Their findings were published Feb. 10 in The Astrophysical Journal.

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Astronomers Rule Out A Theory Of Everything – Forbes

X-ray image of Perseus black hole region.

As astronomers struggle to understand dark matter, they keep pushing up against a contradiction of evidence. While there is a great deal of indirect evidence for dark matter within galaxies and galactic clusters, there is as yet no direct evidence of dark matter particles. Even worse, the standard model of particle physics, which accurately predicts the particles we observe, has no room for any undiscovered particle that could be dark matter.

For this and other reasons, theorists have proposed extensions of the standard model with an even larger range of theoretical particles. It's an effort to create some grand theory of everything. One popular extension includes a type of particle known as axions.

Axions are pretty controversial in physics. Theorists tend to like them because they would solve some bothersome issues with quantum theory. Some astronomers like them because some axions behave just like cold dark matter. Many experimentalists don't like them because there is some evidence to disprove them. Measurements of nuclear spin have eliminated many axion models, and spectral observations of galaxies rule most of them out as a candidate for dark matter.

But axions would be so gosh darn useful that as soon as one type of axion is ruled out folks start looking for the ones that haven't been eliminated. That's where a new study comes in. This one is a bit different because it uses distant galaxies to do particle physics.

If axions exist, then they would be produced by high energy interactions. These are the kind of interactions produced in particle accelerators, but they also occur naturally near black holes. So the team looked at x-ray signals coming from an active black hole in the galaxy NGC 1275.

Because axions would have more mass than known particles within the standard model, they should decay into lighter particles. Very low mass axions would decay directly into photons with specific wavelengths. So the team looked at the spectral pattern of x-rays from NGC 1275, and found no evidence for axions. So more axion models are ruled out, though as the authors point out there are still some axion models that haven't been disproven.

So once again it looks like axions don't exist. This goes to show that no matter how elegant your model is, it can still be completely wrong.

Reference: Abel, Christopher, et al. "Search for axionlike dark matter through nuclear spin precession in electric and magnetic fields." Physical Review X 7.4 (2017): 041034.

Reference: Ajello, M., et al. "Search for spectral irregularities due to photonaxionlike-particle oscillations with the Fermi Large Area Telescope." Physical Review Letters 116.16 (2016): 161101.

Reference: Reynolds, Christopher S., et al. "Astrophysical limits on very light axion-like particles from Chandra grating spectroscopy of NGC 1275." The Astrophysical Journal 890.1 (2020): 59.

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Astrophysicists Perform Test of String Theory | Astronomy – Sci-News.com

Astrophysicists using NASAs Chandra X-ray Observatory have looked for signs of an as-yet undetected particle predicted by string theory, a set of models intended to tie together all known forces, particles, and interactions.

Reynolds et al used Chandra to look for extraordinarily low-mass axion-like particles in the Perseus galaxy cluster, a group of galaxies located 240 million light-years away from Earth. The observation lasting over five days showed no evidence for certain axion-like particles, which some theorists think can explain dark matter. The lack of detection in these Chandra observations helps rule out some versions of string theory, a set of models intended to tie together all known forces, interactions, and particles. Image credit: NASA / CXC / University of Cambridge / Reynolds et al.

Until recently I had no idea just how much X-ray astronomers bring to the table when it comes to string theory, but we could play a major role. If these particles are eventually detected it would change physics forever, said studys lead author Dr. Christopher Reynolds, a researcher at the University of Cambridge.

The particle that Dr. Reynolds and colleagues were searching for is called an axion.

This as-yet-undetected particle should have extraordinarily low mass. Theoretical physicists do not know the precise mass range, but many theories feature axion masses ranging from about a millionth of the mass of an electron down to zero mass.

Some scientists think that axions could explain the mystery of dark matter, which accounts for the vast majority of matter in the universe.

One unusual property of this ultra-low-mass particle would be that it might sometimes convert into photons (that is, packets of light) as they pass through magnetic fields. The opposite may also hold true: photons may also be converted into axions under certain conditions.

How often this switch occurs depends on how easily they make this conversion, in other words on their convertibility.

Some scientists have proposed the existence of a broader class of ultra-low-mass particles with similar properties to axions.

Axions would have a single convertibility value at each mass, but axion-like particles would have a range of convertibility at the same mass.

While it may sound like a long shot to look for tiny particles like axions in gigantic structures like galaxy clusters, they are actually great places to look, said studys co-author Dr. David Marsh, a researcher at Stockholm University.

Galaxy clusters contain magnetic fields over giant distances, and they also often contain bright X-ray sources. Together these properties enhance the chances that conversion of axion-like particles would be detectable.

To look for signs of conversion by axion-like particles, the astrophysicists examined over five days of Chandra observations of X-rays from material falling towards the supermassive black hole in the center of NGC 1275, the central galaxy of the Perseus galaxy cluster.

They studied the Chandra spectrum, or the amount of X-ray emission observed at different energies, of this source.

The long observation and the bright X-ray source gave a spectrum with enough sensitivity to have shown distortions that scientists expected if axion-like particles were present.

The lack of detection of such distortions allowed the researchers to rule out the presence of most types of axion-like particles in the mass range their observations were sensitive to, below about a millionth of a billionth of an electrons mass.

Our research doesnt rule out the existence of these particles, but it definitely doesnt help their case, said studys co-author Dr. Helen Russell, a researcher at the University of Nottingham.

These constraints dig into the range of properties suggested by string theory, and may help string theorists weed their theories.

The results appear in the Astrophysical Journal.

_____

Christopher S. Reynolds et al. 2020. Astrophysical Limits on Very Light Axion-like Particles from Chandra Grating Spectroscopy of NGC 1275. ApJ 890, 59; doi: 10.3847/1538-4357/ab6a0c

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How Astronomers Could Sharpen The Image Of A Black Hole – Forbes

Different photon paths create layers of light.

The supermassive black hole in M87 has a mass of more than 6 billion Suns. It is so large that its event horizon could easily swallow our entire system. It is also 53 million light-years away, which makes it rather difficult to observe. Its apparent size is similar to that of a baseball placed on the surface of the Moon.

To observe such a distant and faint object, it took an international team of radio astronomers. They tied together observatories from all over the world through a process known as interferometry, and created a virtual telescope nearly the size of Earth. Months of gathered data then had to be shipped to computational facilities where the data was processed to create the first direct image of a black hole.

The first image of a supermassive black hole.

While this was a monumental achievement, the image itself seemed rather unimpressive to some. That's it? All this work for a blurry image with a dark center? What does that tell us about a black hole? Like most radio images, looks can be deceiving. While the black hole image is great for a bit of press, it's just how we represent the radio data in a visually appealing way.

Even this processed image isn't an image of the black hole itself. Black holes don't emit light, so they are effectively invisible. What this image represents is light that has been gravitationally focused in our direction, kind of like the headlight of a car. The black hole is bathed in a glow of radio light, and when some of the light passes close to the black hole the direction changes radically. The only light we see is the light deflected along our line of sight. The dark region is the shadow cast by the black hole within the radio glow.

From this first data astronomers were able to pin down some of the black hole properties, such as its mass and rotation. Of course, astronomers would like to learn even more, which is a challenge given that even this blurry image pushed the limits of our technology. But a new paper published in *Science Advances* shows how it might be done.

When a black hole is surrounded by hot gas, light can be focused by gravity to create a shadow of ... [+] the black hole.

The key is to understand how light is deflected near a black hole. While a black hole deflects light like a lens, it does so in rather odd ways when the light gets really close. The most common deflection is for the path of light to simply change direction. This is most of the light we see in the black hole image. But get a little closer, and the light can orbit the black hole once before being sent on its way. A bit closer, and it can orbit two times, or three times.

Light taking an ever-closer approach can reach a point where light orbits the black hole indefinitely. Photons can orbit a black hole similar to the way planets orbit a star. This orbit region for light is known as the photon sphere. It marks the limit of a stable orbit around a black hole. General relativity makes strong predictions about the size and shape of the photon shell. If we can observe it, we could test relativity in new ways.

This new research shows how all these different paths are contained in the radio data we gather, and how these layers create distinct signatures within interferometry. In other words, to observe the photon sphere, we don't need to create ever-sharper images of a black hole. Instead, we can look for these signatures to pull out the data of each layer.

At the moment this technique is beyond the ability of the current Event Horizon Telescope, but it does show how further advances in radio astronomy could lead to a much greater understanding of black holes.

Reference: Johnson, Michael D., et al. "Universal Interferometric Signatures of a Black Hole's Photon Ring." Science Advances Vol. 6, no. 12, (2020).

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Weekly Round-Up Of Space And Astronomy Opportunities For Africans – Space in Africa

develoPPP.de CLASSIC Development partnerships with the private sector

BMZ can support your companys innovative projects and commercial investments in developing and emerging-market countries provided that they offer long-term benefits for the local population.

Projects typically cover a wide range of sectors and themes from training local experts and piloting innovative technologies and demonstration units to protecting value chains and improving manufacturers environmental and social standards.

Target groupCompanies with project ideas that offer potential development benefits and do not simply constitute an investment in theiractual core business.

FundingBetween EUR 100,000 and EUR 2 millionof public funding on top of your companys own contribution ( 50%)

CriteriaMinimum annual turnover: EUR 800,000Minimum number of employees: 8At least two years of audited financial statements

TermUp to three years

Click BMZ Offers Financial And Technical Support To Public & Private Companies to apply and get further information.

Startups and SMEs With Innovative Solutions To Submit Application To Tackle Coronavirus Outbreak

The European Commission is calling for startups and SMEs with technologies and innovations that could help in treating, testing, monitoring or other aspects of the Coronavirus outbreak to apply urgently to the next round of funding from the European Innovation Council.

With a budget of 164m,this callis bottom-up, that is, there are no predefined thematic priorities and applicants with Coronavirus relevant innovations will be evaluated in the same way as other applicants. Nevertheless, the Commission will look to fast track the awarding of EIC grants and blended finance (combining grant and equity investment) to Coronavirus relevant innovations, as well as to facilitate access to other funding and investment sources.

The EIC is already supporting a number of startups and SMEs with Coronavirus relevant innovations awarded funding in previous rounds. This includes theEpiShuttle projectfor specialized isolation units and them-TAP projectfor filtration technology to remove viral.

The deadline for applications to theEIC Acceleratoris17:00 on Friday 20 March (New deadline)(Brussels local time).

Click Startups and SMEs With Innovative Solutions To Submit Application To Tackle Coronavirus Outbreak to apply and get further information.

NewSpace Systems is Hiring A Design Engineer & Product Support Engineer; Apply

NewSpace Systems, the product development, and manufacturing aerospace engineering company in Somerset West is looking for a Design Engineer & Product Support Engineer to work in Somerset West, Western Cape, permanently.

DESIGN ENGINEER(Somerset West, Western Cape 7130, Permanent)

A permanent position for a design engineer to take responsibility for new electro-mechanical product design, development, and verification on various projects working within a multidisciplinary team.

Qualifications:

B.Sc/B.Eng degree in Engineering (preferably electronic, mechanical or mechatronic) from a recognized institution.

Experience (ideally within aerospace or defence industry):

High-reliability electronic product design, realization, and environmental testing(>3 years)

Additional knowledge areas that would strengthen the application

PRODUCT SUPPORT ENGINEER(Somerset West, Western Cape 7130, Full-time, Permanent)

A permanent position for a product support engineer to take responsibility for the industrialization, support, customization, and improvement of Companys products and processes.

Qualifications:

Experience (ideally within aerospace or defence industry):

(Preferably in Solid Works)

Click NewSpace Systems is Hiring A Design Engineer & Product Support Engineer; Apply to apply and get further information.

SANSA Calls For A Space Weather Project Lead; Apply Now

The South African National Space Agency requires a project specialist for a period of three years to apply sound project management principles to the operational space weather centre project (hereafter called the project) the aim of the project is to move the limited operational space weather centre to a full 24/7 operational centre with all the identified products and services in place, the capability and knowledge strengthened and the required certification (which includes ISO 9001:2015) achieved. The project has already started and a number of mechanisms have already been applied. The incumbent will need to take these over and ensure continuity.

The space weatherproject leadwill be required to plan, budget, oversee and document all aspects of this project. The project lead will have the overall responsibility for the successful planning, design, execution, monitoring, controlling and closure of the project. The successful incumbent will also be required to assist in developing a marketing strategy and exploring funding opportunities for the centre.

Responsibilities will include:

Closing date: 24 March 2020

Click SANSA Calls For A Space Weather Project Lead; Apply Now to apply and get further information.

Registration Open To Participate In The 2020 Farming by Satellite Prize

The Farming by Satellite Prize rewards young innovators exploring the use of satellite technologies to improve agriculture and reduce environmental impact. Applications for the 2020 Prize open 16 March.

Kicking off its 5th edition, the Farming by Satellite Prize is designed to encourage young professionals, farmers and students in Europe and Africa to create new, sustainable and environmentally friendly solutions using Copernicus, EGNOS and Galileo. A total Prize pool of 10,000 is up for grabs in 2020 with prizes distributed among the top three European applicants as well as the best idea submitted to the Special Africa Prize. Returning this year, the Special Africa Prize encourages young Africans to seek satellite-based solutions for their agricultural needs.

How does it work?

Each team nominates a leader to register their team and idea on the application platform. Once registered, teams can start on their applications and return to the platform to keep working on their ideas until the deadline of 15 June. All applications will then be evaluated, and the top finalists will be selected to continue to the deep dive phase. This next phase will see teams submit a pitch deck to compete for the chance to travel to the live pitch and award ceremony event. Two phases, live pitching, and 10k up for grabs.

Who can participate?

Individuals or teams of up to four people are invited to register online between 16 March and 15 June 2020. All team members must be under the age of 32 by the submission deadline and be a citizen or resident of a European or African country. All applicants must be at least of 18 years of age by the date of application submission deadline.

The prize

1st place 5,0002nd place 3,0003rd place 1,000

Special Africa Prize 1,000

And an expenses-paid trip to participate in the final stage of the competition, and the Award Ceremony. A group of expert judges will review every idea.

Event Date (estimated)1 Announcement of Contest 16 March 20202 Deadline Open Call (First Phase) 15 June 20203 Announcement of the results of Open Call (First Phase) 30 June 20204 Deadline Deep Dive Phase (Second Phase) 30 September 20205 Announcement of the Deep Dive results 16 October 20206 Final step Live Pitches & Awards Ceremony November-December 2020

Click Registration Open To Participate In The 2020 Farming by Satellite Prize to apply and get further information.

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Weekly Round-Up Of Space And Astronomy Opportunities For Africans - Space in Africa

Astronomy | Definition of Astronomy by Merriam-Webster

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: the study of objects and matter outside the earth's atmosphere and of their physical and chemical properties

Some may find it easy to confuse astronomy and astrology. At one time, these two words actually were synonymous (that is, astronomy once meant what astrology means today), but they have since moved apart from each other. In current use, astronomy is concerned with the study of objects and matter outside the earth's atmosphere, while astrology is the purported divination of how stars and planets influence our lives. Put bluntly, astronomy is a science, and astrology is not.

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'astronomy.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

12th century, in the meaning defined above

Middle English astronomie, from Anglo-French, from Latin astronomia, from Greek, from astr- + -nomia -nomy

Cite this Entry

Astronomy. Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/astronomy. Accessed 11 Mar. 2020.

More Definitions for astronomy

: a science concerned with objects and matter outside the earth's atmosphere and of their motions and makeup

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Astronomy | Definition of Astronomy by Merriam-Webster

Amateur astronomers help discover incredible teardrop-shaped star – Fox News

After a 40-year search, astronomers have spotted a first-of-its-kind star that pulsates on just one side.

Amateur astronomers played an important role in the discovery by trawling through data from NASAs planet-hunting Transiting Exoplanet Survey Satellite (TESS).

The one-sided pulsator was spotted in the Milky Way about 1,500 light-years from Earth, according to researchers. A light-year, which measures distance in space, equals about 6 trillion miles.

17-YEAR-OLD NASA INTERN MAKES STUNNING DISCOVERY

The star, which is known as HD74423, is about 1.7 times the mass of the Sun.

An artist's impression of the star and its red dwarf "companion". (Gabriel Prez Daz, IAC)

An international team of astronomers harnessed a wealth of data to make the discovery. Their research is published in the journal Nature Astronomy.

"What first caught my attention was the fact it was a chemically peculiar star," said co-author Simon Murphy, Ph.D.from the Sydney Institute for Astronomy at the University of Sydney, in a statement. "Stars like this are usually fairly rich with metals - but this is metal poor, making it a rare type of hot star."

77-YEAR-OLD AMATEUR ASTRONOMER HELPS MAKE STUNNING DISCOVERY

Other astronomers had also started to study the star. "We've known theoretically that stars like this should exist since the 1980s," the study's co-author, Don Kurtz, who is from the U.K.s University of Central Lancashire, said in the statement.

"I've been looking for a star like this for nearly 40 years and now we have finally found one," added Kurtz, who is also the inaugural Hunstead Distinguished Visitor at the University of Sydney.

While astronomers have known about pulsating stars for a long time, stars that oscillate over just one hemisphere are a new phenomenon. HD74423, the researchers explain, is in a binary star system with a red dwarf, or small, cool star. Its close companion distorts the oscillations with its gravitational pull, the researchers explained, in the statement. The clue that led to its discovery came from citizen scientists poring over public data from NASA's TESS satellite, which is hunting for planets around distant stars.

GIANT BLACK HOLE 'SHOULD NOT EVEN EXIST,' STUNNED SCIENTISTS SAY

Because the orbital period of the binary system is less than two days, HD74423 is being distorted into a teardrop shape by the red dwarfs gravitational pull.

"The exquisite data from the TESS satellite meant that we could observe variations in brightness due to the gravitational distortion of the star as well as the pulsations, said ProfessorGerald Handler from the Nicolaus Copernicus Astronomical Centre in Poland, who is the studys lead author.

Experts believe that other similar stars exist.

NASAS SOLAR ORBITER SET FOR HISTORIC MISSION TO THE SUN

The pulsating star is the latest in a series of fascinating discoveries by astronomers across the globe.

In another project, for example, a 77-year-old amateur astronomerrecently helped discover a rare galaxy double nucleus. Allen Lawrence, a retired electrical engineer, used infrared images from NASAs Wide-field Infrared Survey Explorer to reveal the double nucleus galaxy.

NASA also recently announced that a 17-year-old summer intern made an incredible planet discovery. Wolf Cukier, a student from Scarsdale High School in New York, had just finished his junior year when he started his internship at NASAs Goddards Space Flight Center in Goddard, Md., last summer. Within just a few days, he made an incredible find while sifting through variations in star brightness captured by the space agencys Transiting Exoplanet Survey Satellite (TESS) uploaded to the Planet Hunters TESS citizen science project.

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A signal from a distant system called TOI 1338 turned out to be a planet. The planet, TOI 1338 b, is the first circumbinary planet, or world orbiting two stars, that has been spotted using TESS data.TOI 1338 b is about 6.9 times larger than Earth, which means that it is between the size of Saturn and Neptune.

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The fifth force: Is there another fundamental force of nature? – Astronomy Magazine

The four fundamental forces

Physics textbooks teach that there are four fundamental forces of nature: gravity, electromagnetism, and the strong and weak nuclear forces.

Were quite familiar with the first two forces. Gravity pins us to Earth and pulls us around the sun, while electromagnetism keeps the lights on. The other two forces are less obvious to us because they govern interactions at the tiniest scales. The strong force binds matter together, while the weak nuclear force describes the radioactive decay of atoms.

Each of these forces is carried by a kind of subatomic particle that physicists call a boson. For example, photons are the force particle in electromagnetism. Gluons carry the strong nuclear force. W and Z bosons are responsible for the weak nuclear force. Theres even a hypothetical boson for gravity called the graviton, though scientists havent proven its existence.

However, if you ask many theoretical physicists, theyll probably tell you we havent discovered all the forces of nature yet. Others are likely out there, just waiting to be discovered.For example, some suspect that discovering dark matter may reveal a weak new force.

And thats where the Hungarian group comes in. Without getting too lost in the details, the group shot protons at a thin sample of lithium-7, which then radioactively decayed into beryllium-8. As expected, this created pairs of positrons and electrons. However, the detectors also picked up excess decay signals that suggested the existence of a potential new and extremely weak particle. If it exists, the particle would weigh in at about 1/50 the mass of a proton. And because of its properties, it would be a boson a force-carrying particle.

But history is littered with reasons to be skeptical of new additions. In recent decades, other groups have also claimed to have found a fifth force, only to have their claims quietly fade away. Around the year 2000, one group proposed a new force, called quintessence, to explain the then-recent discovery of dark energy. In the 1980s, a group of physicists at MIT said theyd found a fifth force, dubbed hypercharge, that served as a kind of anti-gravity. Yet here we are with textbooks still teaching the same four fundamental forces we had decades ago.

That means the most likely explanation for the unexplained new signal is that theres something off with the Hungarian detectors setup. However, no one is disputing the data. The findings were peer-reviewed and published in the journal Physical Review Letters the same journal that published the discovery of gravitational waves. Even ideas in prestigious journals can sometimes be explained away as systematic error, but thats the way science works.

People are paying attention to see whether this is really a nuclear physics effect or whether its something systematic, Alves says. Its important to repeat those experiments ... to be able to test whether this is real or if its an artifact of the way theyre doing the experiment.

Quest to confirm

And thats precisely what her group hopes to do. Together with a small team, shes proposing to repeat the Hungarian experiment using equipment that already exists at Los Alamos. The national lab has been a leader in nuclear physics since the creation of the atomic bomb. And today, thousands of top physicists still work there on problems ranging from safeguarding and studying our nations nuclear arsenal, to pioneering quantum computers and observing pulsars.

As it turns out, they also have a detector nearly identical to the one used by the Hungarian team.

When you add all that together, Alves believes Los Alamos has exactly the right combination of facilities and expertise to repeat the experiment. Thats why her group quietly worked on their proposal for the last six months, and recently submitted a funding request for review. To gain approval, it will have to win out in an annual competition alongside other projects at the national lab.

In recent years, several other groups likewise have suggested theyll look for this force. But at the moment, Alves believes they're the main group in the U.S. working to confirm or refute the finding. If they cant gain approval, it may be years before a university or other group can secure both the funds and expertise to repeat the experiment with the same sort of parameters the Hungarians used.

As with all extraordinary claims, this potentially paradigm-shifting discovery will require extraordinary evidence before people accept it. So we may have to wait a while before we know whether the X17 particle and its potential fifth force will revolutionize physics, or take its place atop the dustbin of debunked and discarded discoveries.

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The fifth force: Is there another fundamental force of nature? - Astronomy Magazine

The Sky This Week from March 6 to 13 – Astronomy Magazine

Friday, March 6A waxing Moon hangs out in Cancer the Crab all night. About 18 to its west is yellowish Pollux in Gemini, and nearly 4 farther is the whiter-hued Castor. The latter appears to the naked eye as a magnitude 1.6 star, but it is actually a six-star system. The two brightest stars, Castor A and B, can be separated with a small telescope.A third component, the dimmer Castor C, lies about 1.2' away.

Saturday, March 7Night owls can take a gander at one of the best globular clusters visible in the Northern Hemisphere. Messier 13, also known as the Hercules Cluster, rises above the horizon with its namesake constellation about 9 P.M. local time but is well poised for clearer viewing by midnight and into the early hours of the morning. This cluster of ancient stars circling our galaxy contains more than 100,000 members that combine to create its magnitude 5.8 glow.

Sunday, March 8Venus and Uranus lie just over 2 apart in the evening sky. You can use Venus to easily find the ice giant by using binoculars or a telescope to locate a pair of 7th-magnitude stars about 1.2 to the lower left of Venus. Travel twice that distance in the same direction to reach brighter Uranus, glowing at magnitude 5.9.

Neptune is in conjunction with the Sun at 8 A.M. EDT. However, its position means it is lost from view in the bright glare of our star. It will make its way back to visibility by the end of next month.

For most of the United States and Canada, daylight saving time begins at 2 A.M. local time this morning. Set your clocks ahead one hour.

Monday, March 9Venus passes 2 north of Uranus this morning at 11 A.M. EDT. The inferior planet will continue to move noticeably through Aries as March progresses, while the more distant ice giant moves only about 1 eastward during the month.

Mercury is stationary at 4 A.M. EDT. From here, it will move toward its greatest western elongation, which it will reach on the 23rd.

The Full Moon occurs at 1:48 P.M. EDT. This evening, our satellite rises in Virgo as the Sun is setting and will set in the morning around dawn. Full Moon is an excellent time to easily observe Luna with or without additional optical assistance; keep in mind that the Moon will appear especially bright through binoculars or a telescope. The Full Moon also washes out much of the sky, making this time best for observing planets and brighter stars, but poor for deep-sky objects such as galaxies and nebulae.

Tuesday, March 10The Moon reaches perigee, its closest point to Earth in its orbit, at 2:30 A.M. EDT. At that time, it will sit 221,905 miles (357,121 kilometers) from our planet.

When the Full Moon occurs at perigee, it is sometimes called a supermoon by the media. Although this is an evocative name, the Full Moon will only appear about 7 percent larger than average, which is difficult if not impossible for observers to discern.

Original post:

The Sky This Week from March 6 to 13 - Astronomy Magazine

This gas-giant exoplanet has water-rich clouds. Here’s why it thrills astronomers. – Space.com

Three teams of astronomers have been fascinated by an alien world known as K2-18b. But what's all the fuss about?

In September, two teams announced that they had found signs of liquid water in the planet's atmosphere a landmark discovery in the search for potentially habitable alien worlds. But the mere presence of water isn't the only condition necessary for life. Other conditions, like temperature and pressure, can also affect a planet's habitability. Now, a third team reports that the pressures of liquid water on the same world may be good for life to evolve another intriguing development for scientists.

"We recognized pretty early on that this is a very unique target," Bjrn Benneke, an astronomer at the University of Montreal, told Space.com. Benneke led one of the teams that announced the atmospheric analysis in the September 2019 study, which was published in The Astrophysical Journal Letters in December. He presented the findings in January at a meeting of the American Astronomical Society.

Related: 7 ways to discover alien planets

Benneke and his colleagues used the Hubble and Spitzer space telescopes to study K2-18b a dozen times over a three-year period, to collect precise observations of its atmosphere.

Although scientists have studied exoplanet atmospheres before, those worlds have been larger than K2-18b, which is only about 2.6 times the size of Earth and 8.5 times its mass. The planet's small size made the observations especially challenging, requiring multiple detailed measurements that, combined, could provide a more in-depth probe of the world.

"Nothing like this has been done before," Benneke said.

K2-18b is 110 light-years away, in the constellation Leo, where it orbits a small but active type of star that can hurl bursts of radiation at orbiting planets. Although the star is smaller and dimmer than the sun, K2-18b's 33-day orbit means the planet receives roughly the same amount of energy from its star as Earth receives from the sun.

The star's small size makes it easier to detect details of a diminutive planet like K2-18b because observations of a planet depend on how much light it blocks as it passes in front of its star from Earth's perspective. A smaller planet blocks less light than a larger one, but a smaller star has less light to block, making that small signal somewhat easier to see. (The planet's orbit also helped scientists capture multiple passes across its star.)

In the Hubble and Spitzer observations, Benneke and his team found the signature of water in the exoplanet's atmosphere and not just any form of water. "Even more exciting, we discovered in the data that there's a cloud deck on the planet," Benneke said.

The clue was that starlight beaming through the atmosphere came to an abrupt stop at a certain altitude. Benneke and his colleagues used models to determine that the height was the perfect pressure and temperature for water to survive.

"The only plausible explanation is that these are liquid water clouds, very similar to what we have on Earth," Benneke said.

As the clouds fill with water droplets, they most likely create rainfall. But that rain would never touch the ground. Instead, it would fall until temperatures and pressures caused it to evaporate once again, the researchers said. Benneke compared rainfall on K2-18b to terrestrial virga, which occurs when high temperatures and pressures cause rain to evaporate before it reaches the ground.

Finding a similar weather pattern on an exoplanet is an intriguing prospect to Benneke.

"[K2-18b] is the coldest planet with [atmospheric] detection, the smallest planet, the least-massive planet," he said. "To me, it's the most exciting one."

Although K2-18b has the right conditions for Earth-like clouds to form, that doesn't make the planet itself Earth-like. Instead, it is classified as a sub-Neptune, a gas giant without a surface. NASA's Kepler spacecraft determined that sub-Neptunes are likely the most common type of exoplanets in the Milky Way, making up more than three-fourths of the planetary population.

Nonetheless, astronomers are having a difficult time understanding the relatively small gas giants, and that's one reason the K2-18b findings are so exciting. "We don't quite know what's going on with these planets," Benneke said. "It's probing this regime of planets that we have a very poor understanding of right now."

Sub-Neptunes have masses that fall somewhere between Earth and Neptune, and there's no analogue in the solar system. Understanding worlds like K2-18b can help improve scientists' knowledge of how planets grow and evolve. "If you want to understand planets as a whole, the diversity of planets, it's very critical that you understand the most common ones," Benneke said.

Follow Nola Taylor Redd on Facebook and on Twitter at @NolaTRedd. Follow us on Twitter @Spacedotcom and on Facebook.

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This gas-giant exoplanet has water-rich clouds. Here's why it thrills astronomers. - Space.com

Get ready to explore the "Cosmos" with Neil deGrasse Tyson – Astronomy Magazine

Hold on, a quick aside. When you say the word billion on the show, I feel like you think for a moment before you pronounce it. Were you careful in how you said the word billion, not to sound too much like Carl Sagan?

[laughs] You know, you can't step into a Sagan slot and not be conscious of the number billion. There were a couple of times I would punch it up a notch, almost as an homage, but otherwise not. I do remember a couple of times when I didn't think the editors would use those cuts where I went high on the intonation scale.

Sorry, back to our conversation. Many people who think about the future of humanity imagine us someday merging with computers. Does that seem credible to you?

No, not really. And I know I'm an outlier here. It doesn't feel credible because, you know, I have in my palm access to the internet. So you're saying, "Oh, now I'm going to wire that with a USB connection into my brainstem." How fast access am I going to want? Is it not fast enough to pull this phone out of my pocket? For me, the fact that it is right with me every day I leave the house, that doesn't leave me wanting this thing to be surgically connectedto get silicon surgically connected to my physiology.You dont crave more speed, more connection to information?

Heres a related analogy. Air transportation, in its early decades, was about how fast can you fly to your destination, how to minimize the time you're on an airplane. So planes got faster and faster. We got to jets instead of propellers, and then we got the supersonic transport. Then things started pulling back. Why? Well we had the 747. Planes got larger, they had better food, they had more leg room. The seats were more comfortable. Today we have the internet on your flight, we have any movie you'd ever want to watch, we have music.

The idea that speed was so important that we would want it at all costs gave way to a different idea: I am comfortable in this environment, and in fact I can even catch up on things. I can binge on shows I didn't have time to watch at home. You can come off the plane in a better place than you were before you entered it. And so no one is trying to make planes faster today. In fact, they're slower than before. The typical speeds are 500 to 550 miles per hour, whereas when I was growing up, the speeds were 600 to 650 miles per hour.

So to say we're going to become one with artificial intelligence because we want the speed, I just don't see that happening.

A lot of people also dream that computer technology will bring us immortality. Thats a possible world they long for: We will upload our brains, and then we'll never die.

Well, I would ask, if you upload your brain, how do you know that's still you? I don't think we understand consciousness enough to assert that. We can say that's your knowledge. That thing, that entity has all the same knowledge that you have, but is that you? I don't know.

We know that an identical twin has identical DNA to you yet they are not you. You don't have their thoughts and they don't have your thoughts. So this notion of uploading your consciousnessI'm not going to pay close attention to it until we have a secure understanding of what consciousness is in the first place.

That's a whole other mysterious world, the mental world that is still barely being explored.

Right. Its a frontier perhaps as vast as the universe itself.

Excerpt from:

Get ready to explore the "Cosmos" with Neil deGrasse Tyson - Astronomy Magazine

We asked astronomers: are we alone in the Universe? The answer was surprisingly consistent – The Conversation AU

Are we alone in the Universe? The expert opinion on that, it turns out, is surprisingly consistent.

Is there other life in the Universe? I would say: probably, Daniel Zucker, Associate Professor of astronomy at Macquarie University, tells astrophysics student and The Conversations editorial intern Antonio Tarquinio on todays podcast episode.

I think that we will discover life outside of Earth in my lifetime. If not that, then in your lifetime, says his fellow Macquarie University colleague, Professor Orsola De Marco.

And Lee Spitler, a Senior Lecturer and astronomy researcher at the same institution, was similarly optimistic: I think theres a high likelihood that we are not alone in the Universe.

The big question, however, is what that life might look like.

Read more: The Dish in Parkes is scanning the southern Milky Way, searching for alien signals

Were also hearing from Danny C Price, project scientist for the Breakthrough Listen project scanning the southern skies for unusual patterns, on what the search for alien intelligence looks like in real life - and what its yielded so far.

Read more: 'The size, the grandeur, the peacefulness of being in the dark': what it's like to study space at Siding Spring Observatory

Everything you need to know about how to listen to a podcast is here.

Additional audio credits

Kindergarten by Unkle Ho, from Elefant Traks.

Lucky Stars by Podington Bear, from Free Music Archive

Illumination by Kai Engel, from Free Music Archive

Podcast episode recorded and edited by Antonio Tarquinio.

Shutterstock

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We asked astronomers: are we alone in the Universe? The answer was surprisingly consistent - The Conversation AU

Dine Roundup: Wine dinners, Astronomy on Tap and more in Baton Rouge this week – 225 Baton Rouge

Get your friends together for Friends trivia this Tuesday

Think you have the unagi to participate in Friends Trivia at Reginellis Pizzeria Tuesday, March 10? Well, get your gang of one to six people together as you compete for Reginellis gift cards. And as always, the best team name wins a free pitcher of NOLA Blonde. Could you be any more excited? If so, be sure to share plenty of food while youre at it, too, because we all know Joey doesnt share food!

Reginellis Pizzeria (Goodwood) is at 684 Jefferson Highway.

Head over to Bin 77 Bistro & SideBar as the restaurant features Single Vineyard wines of the Hartford Court Family Winery on Tuesday, March 10. Besides two flights of white and red wine, there will also be plenty of chef and sommelier boards, starting at 7 p.m., which will include various cheeses, charcuteries and cooked proteins to go with the wines.

To make a reservation, call Bin 77 at 763-2288.

Bin 77 Bistro & SideBar is at 10111 Perkins Rowe, Ste. 160.

Curious about whether or not Experiment 626 and Chewbacca could exist, and what their lives might be like? You and your kids can find out as Astronomy on Tap celebrates its second anniversary Wednesday, March 11. LSU grad student Rachel Malacek will talk about the possible adventures of Stitch (from Lilo and Stitch), and fellow grad student Aaron Ryan will discuss the life of Chewbacca.

There will be plenty of games, raffles, glow sticks and spaced-themed drinks for everyone, too.

The Varsity Theatre is at 3353 Highland Road.

Need to wine down? Join Rouj Creole Wednesday, March 11, as the new restaurant hosts another wine dinner. You can enjoy the chefs four-course meal, included with a Duckhorn wine pairing, 6:30-9:30 p.m.

To make a reservation, call Rouj at 614-2400.

Rouj Creole is at 7601 Bluebonnet Blvd., Ste 100.

Join Red Stick Spice Co. as its team teaches you how to demystify pantry staples with Middle Eastern foods Thursday, March 12. You can look forward to tahini cookies, roasted eggplant, pomegranate molasses and more, 6-8 p.m.

This class is available for those 16 and older. Tickets are available here.

Red Stick Spice Company is at 660 Jefferson Highway.

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Dine Roundup: Wine dinners, Astronomy on Tap and more in Baton Rouge this week - 225 Baton Rouge

Now Whats Going On With Betelgeuse? The Future Supernova Just Isnt That Cool, Say Astronomers – Forbes

Observations of the star Betelgeuse taken by the ESOs Very Large Telescope in January and December ... [+] 2019, which show the stars substantial dimming.

Astronomers expect Betelgeuse to explode as a supernova within the next 100,000 years, when its core collapses. However, evidence is mounting that the stars dimming, which began in October, isnt necessarily a sign of an imminent explosion.

A new paperaccepted to Astrophysical Journal Letters and published on the preprint site arXiv entitled Betelgeuse Just Isn't That Cool: Effective Temperature Alone Cannot Explain the Recent Dimming of Betelgeuse by Emily Levesque, a UW associate professor of astronomy, andPhilip Massey, an astronomer with Lowell Observatory, suggests that Betelgeuse isnt dimming because its about to explode.

Its just dusty.

Astronomers have been on alert since late in 2019 when Betelgeusefound in the constellation of Orionbegan to visibly dim, eventually dropping to around 40% of its usual brightness before slightly brightening in recent weeks.

Could it be about to explode as a massive supernova?

Probably not. Levesque and Massey made optical spectrophotometry observations of Betelgeuse on February 14, 2020 at Lowell Observatory in Flagstaff, Arizona, to calculate the average surface temperature of the red supergiant star. Their results indicate that Betelgeuse is significantly warmer than expected if the recent dimming were caused by a cooling of the stars surface.

This evidence suggests that Betelgeuse has probably sloughed off some material from its outer layers, something that is common with red supergiant stars. We see this all the time in red supergiants, and its a normal part of their life cycle, said Levesque. Red supergiants will occasionally shed material from their surfaces, which will condense around the star as dust. As it cools and dissipates, the dust grains will absorb some of the light heading toward us and block our view.

The first direct image of a star other than our sun, taken with the Hubble Space Telescope. ... [+] Betelgeuse is an enormous star in the constellation Orion. This ultraviolet image shows a bright spot on the star that is 2000 degrees centigrade hotter than the rest of the surface. The picture on the right shows the constellation Orion, with Betelgeuse marked by a yellow cross. The star's size relative to the earth's orbit is also shown. (Photo by CORBIS/Corbis via Getty Images)

How do you take a stars temperature?

The astronomers calculated Betelgeuses temperature by looking at the spectrum of light emanating from it. Emily and I had been in contact about Betelgeuse, and we both agreed that the obvious thing to do was to get a spectrum, said Massey. I already had observing time scheduled on the 4.3-meter Lowell Discovery Telescope, and I knew if I played around for a bit I would be able to get a good spectrum despite Betelgeuse still being one of the brightest stars in the sky.

They looked for the telltale signs of light that had been absorbed by titanium oxide, which forms in the upper layers of large, relatively cool stars like Betelgeuse. By their calculations, Betelgeuses average surface temperature on February 14 was about 3,325 Celsius/6,017 Fahrenheit.

Thats only 50-100 Celsius cooler than calculated in 2004.

Orion rising behind the iconic Hoodoos on Highway 10 east of Drumheller, Alberta, near East Coulee, ... [+] on a moonless January night, with illumination by starlight and by a nearby yardlight providing some shadows and warmer illumination. Clouds are beginning to move in and are providing the natural star glows. (Photo by: Alan Dyer /VW PICS/Universal Images Group via Getty Images)

Orion rising behind the iconic Hoodoos on Highway 10 east of Drumheller, Alberta, near East Coulee, ... [+] on a moonless January night, with illumination by starlight and by a nearby yardlight providing some shadows and warmer illumination. Clouds are beginning to move in and are providing the natural star glows. (Photo by: Alan Dyer /VW PICS/Universal Images Group via Getty Images)

So, not much has changedand dimming should be ruled-out. A comparison with our 2004 spectrum showed immediately that the temperature hadnt changed significantly, said Massey. We knew the answer had to be dust. The theory is that newly formed dust is absorbing some of Betelgeuses light. The other possibility is that huge convection cells within Betelgeuse had drawn hot material up to its surface, where it had cooled before falling back into the interior. A simple way to tell between these possibilities is to determine the effective surface temperature of Betelgeuse, said Massey.

However, if youre hoping to see Betelgeuse go supernova and shine brightly day and night for weeks or months, keep looking. Red supergiants are very dynamic stars, said Levesque. The more we can learn about their normal behaviortemperature fluctuations, dust, convection cellsthe better we can understand them and recognize when something truly unique, like a supernova, might happen.

Wishing you clear skies and wide eyes.

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Now Whats Going On With Betelgeuse? The Future Supernova Just Isnt That Cool, Say Astronomers - Forbes


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