Monthly Archives: June 2021

Chryssa Kouveliotou, professor and chair of the Department of Physics in the Columbian College of Arts and Sciences (CCAS), was awarded the Shaw Prize in Astronomy for her contributions to our understanding of magnetars, a class of highly magnetized neutron stars that are linked to a wide range of spectacular, transient astrophysical phenomena.

The Shaw Prize is an international award to honor individuals who are currently active in their fields and who have recently achieved distinguished and significant advances, made outstanding contributions in academic and scientific research or applications, or who in other domains have achieved excellence. The award is dedicated to furthering societal progress, enhancing quality of life and enriching humanity's spiritual civilization.

I am very honored and at the same time very humbled for this great award, Dr. Kouveliotou said. I am grateful to all my colleagues who helped me along the way and believed and supported me in my journey. I feel that this honor is the best way I could celebrate my entire life and career.

Dr. Kouveliotou, a member of the National Academy of Sciences, is George Washington Universitys first recipient of the Shaw Prize. She was honored alongside Victoria M. Kaspi, a professor of Physics at McGill University in Canada. Through the development of new and precise observational techniques, the researchers confirmed the existence of neutron stars with ultra-strong magnetic fields and characterized their physical properties. Their work has established magnetars as a new and important class of astrophysical objects.

Dr. KouveIiotous research in the field of astrophysics is nothing short of groundbreaking, said CCAS Dean Paul Wahlbeck. Her work has served to enlighten our understanding of the very origins and expansion of our universe. I congratulate her on this well-deserved honor.

Neutron stars are the ultra-compact remnants of stellar explosions. Most are rapidly rotating with periods of milli-seconds to seconds and emit powerful beams of electromagnetic radiation, observed as pulsars. They are accurate cosmic clocks that enable tests of fundamental physics in the presence of a gravitational field many billion times stronger than that on Earth.

Pulsars also have strong magnetic fields. Magnetic field lines in the progenitor star are frozen in in the stellar remnant as it collapses to become a neutron star. These magnetic fields funnel jets of particles along the magnetic poles, but classical radio pulsars are powered mainly by rotational energy and slowly spin down over their lifetimes.

The magnetar discoveries by Dr. Kouveliotou and Dr. Kaspi were preceded by the theoretical prediction that neutron stars with extreme magnetic fields up to one thousand times stronger than those in regular pulsars could form if dynamo action would be efficient during the first few seconds after gravitational collapse in the core of the supernova. Such objectstermed magnetarswould be powered by their large reservoirs of magnetic energy and not by rotational energy losses.

From observations of a class of X-ray/-ray sources called soft gamma-ray repeaters (SGRs), Dr. Kouveliotou and her colleagues established the existence of magnetars and provided a stunning confirmation of the magnetar model in the late 1990s. The analysis of the data from the Rossi X-ray timing satellite (RXTE), obtained with her proposal, enabled Dr. Kouveliotou in 1998 was able to detect X-ray pulses with a period of 7.5 seconds in the persistent X-ray emission of SGR 1806-20. She then measured a spin-down rate for the pulsar and derived both the pulsar age and the dipolar magnetic field strengthwhich lay within the range of values predicted for magnetars. The spin-down measurements were extremely challenging because of the faintness of the pulsed signal, according to a Shaw Prize press release.

The Shaw Prize was established in 2002 and is managed and administered by the Shaw Prize Foundation, based in Hong Kong. Dr. Kouveliotou and Dr. Kaspi will each receive a $600,000 award.

Read more here:

GW Physics Professor Awarded Shaw Prize in Astronomy - GW Today

Even the darkest cloud is a work of art, when it is illuminated sufficiently.

This is true on Earth even as it is in the heavens.

When stars die, sometimes after billions of years of creating energy and light in their cores, they can bloat up into swollen red giants, enormous and luminous objects. Silicon and carbon in their upper layers can blow out into the space around them, cooling and condensing into grains of material astronomers call dust.

The galaxy is littered with dense clouds of dust, blocking our view of stars behind them due to their opacity. They can appear brown or black, like holes in space, dark and forbidding.

But dust also appears in clouds where stars are being born, and sometimes these infant stars are massive and blue, sending out vast amounts of energy into their birth nebula. And when they do the dust around them reflects that light, sending some of it Earthward, and we see those clouds not as voids but as lustrous, cerulean, even gossamer cosmic threads.

Behold, vdB31.

This is the 31st object cataloged by astronomer Sidney van den Bergh in his list of dark clouds reflecting starlight. Indeed, we call these reflection nebulae to distinguish them from gas clouds glowing under their own power (called emission nebulae).

In this image taken by my friend and astronomer Adam Block, the bright star illuminating vdB31 is called AB Aurigae, an extremely young star just 4 million or so years old, still in the process of settling down after its birth. It has more than twice the mass of the Sun, and is fiercely hot and luminous, visible in binoculars despite its distance of well over 500 light years.

AB Aurigae is so hot it puts out most of its light in the blue part of the spectrum. Moreover, the tiny grains of silicates and carbon tend to let red light pass by them even while blue light tends to be scattered off them, sent in semi-random directions. These factors combine to create the incredibly lovely blue glow to the dust hanging in space around the star. Without it, the wisps and filaments in the dust would be invisible to our eyes.

The star is moving through space as well, and the arc of material immediately to the star's right may be due to that; the star blows a wind of particles that may be pushing against the dust, creating that bow wave.

On a scale far too small to be seen in Block's image but revealed in Hubble Space Telescope images taken in the 1990s, the star is embedded in a disk of material from which it formed, hinting at a spiral structure in the disk. Indeed, more recent observations taken using the Very Large Telescope show this pattern very clearly, one that's expected if planets are forming in it. One arm of the spiral shows a distinctive kink in it that may be where such a planet is located.

AB Aurigae runs through its nuclear fuel more profligately than the Sun does, and has a lifespan perhaps only one-tenth as long roughly about a billion years. The star is young, and has a long life ahead of it, but an eon from now it too will run low on fuel, enlarge into a vast red giant, and blow dust out into the galaxy. It will have long since left the dusty confines of its location now, but I wonder where it will be, a billion years hence? Will it move through space alone, eructating dark clouds into the vacuum, or will it be coincidentally in yet another region of space with copious gas and dust, adding to the medium around it?

Either way, stars both taketh and giveth. Dust to dust.

All this we know, deduced from images and observations like the ones above.

I was recently interviewed for a podcast and asked why I love astronomy so deeply. I said that the science of it is so amazing and interesting, but it's also just so profoundly exquisite, with objects scattered across the sky of surpassing beauty.

I hope I have shown you an example of this here, and that you agree... upon reflection.

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The delicate beauty of illuminated dust - SYFY WIRE

COLUMBIA, Md., June 4, 2021 /PRNewswire/ --Astronomers are still trying to understand how stars and galaxies formed in the early universe. Now,scientists,using theStratospheric Observatory for Infrared Astronomy, (SOFIA), have new clues from a glowing nebula filled with clouds of hot gas and dustknown as RCW 120. Data from SOFIA suggestthat this nebula may be representative of how stars formed in the early universe.

Scientists using SOFIA, a joint project of NASA and the German Space Agency at DLR, found the stellar wind emanating from the nebula's central massive star is making the nebula expand rapidly. The expansion is triggering the birth of stellar neighbors at breakneck speeds and revealing the nebula is younger than previously believed. The results are published in Science Advances.

Located in the southern Milky Way about 4,300 light years from Earth, in clouds near the constellation Scorpius, researchers discovered that the powerful stellar winds are expanding the nebula incredibly fast at 33,000 miles per hour (or 53,000 km per hour), which corresponds to 15 kilometers per second. The surrounding gas clouds are getting compressed as the nebula pushes into them triggering the birth of new stars near the clouds' edges."

The speed of expansion was also used to determine the nebula's age. It turns out RCW 120 is much younger than previously believed, having formed less than 150,000 years ago.

"The nebula is giving us a window into what star formation may have been like in the early universe," said Dr. Matteo Luisi, a postdoctoral fellow at West Virginia University in Morgantown, West Virginia. "We can't go back to study the early universe, so we depend on observations like these to understand how the universe transformed from the Big Bang to the universe we see today."

Astronomers call the effects stars have on their neighbors' creation "feedback." But exactly how feedback can help or hinder star formation is still somewhat of a mystery. SOFIA previously found that a stellar wind in the Orion Nebula is clearing a bubble free of material needed to form new stars. Now, in the nebula RCW 120, the energy from the original star is triggering the birth of new generations.

The nebula's young age suggests that star formation triggered by an existing star's feedback can happen very quickly and may have been responsible for the high rate of star formation in the universe's earliest eras.

The observations were made while flying in the skies above Christchurch, New Zealand, in 2019. Using SOFIA's instrument called the German Receiver for Astronomy at Terahertz Frequencies, or GREAT, researchers studied the chemical fingerprint of ionized carbon gas to measure the nebula's expansion speed. Unlike infrared images, this fingerprint measures how fast the gas is moving, which can be used to learn how existing stars are affecting future generations. These results are part of an international project to understand the effects of stellar feedback in a variety of star-forming regions.

ABOUT SOFIA

SOFIA is a joint project of NASA and the German Aerospace Center. NASA's Ames Research Center in California's Silicon Valley manages the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft is maintained and operated by NASA's Armstrong Flight Research Center Building 703, in Palmdale, California.

ABOUT USRA

Foundedin 1969, under the auspices of the National Academy of Sciences at the request of the U.S. Government, the Universities Space Research Association (USRA), is a nonprofit corporation chartered to advance space-related science, technology and engineering. USRA operates scientific institutes and facilities, and conducts other major research and educational programs, under Federal funding. USRA engages the university community and employs in-house scientific leadership, innovative research and development, and project management expertise.More information about USRA is available at http://www.usra.edu.

PR Contact: Suraiya Farukhi, Ph.D.[emailprotected] 443-812-6945

SOURCE Universities Space Research Association

http://www.usra.edu

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Young Nebula Hints at Formation of Stars in Early Universe - PRNewswire

When the pandemic shut down in-person activities, UC Riversides Recreation Department moved its youth and recreation programming online. In the months since, department leaders say they have hit their stride in virtual programming.

The department offers youth camps and programming for pre-teens and teenagers. Shifting those online was challenging as counselors learned what worked best in a virtual environment, said Carl Dugdale, youth program coordinator.

Its definitely more targeted now, Dugdale said. We definitely found our footing.

Last year for its annual Camp Highlander, which normally offers outdoor activities, counselors offered online courses in subjects such as baking, American Sign Language, and coding. Aquatics instructors provided customized swimming lessons for kids with home pools and began a pen-pal program.

The Recreation Department has decided to skip its usual summer session for Camp Highlander and plan for the fall, when in-person activities can resume.

Meanwhile, the department has found success with interactive online programs in three areas: astronomy, neuroscience, and dance squad. About a dozen UCR student volunteers and staff members serve as instructors.

For the Dance Squad classes, instructor Emily Thomas keeps kids energized by blending dance with games, chats, and other activities, Dugdale said.

The astronomy sessions have been among the most popular, featuring interactive software and activities.

For example, one session involved the illustration of a 3D model of the solar system using software. Another exercise involved students creating their own simulations of exoplanets, said Xinnan Du, an outreach director and postdoctoral scholar in astronomy who has overseen the astronomy sessions.

The astronomy nights began with about 35 registered participants in summer 2020, but for the spring session that has grown to 257. A YouTube livestream was created in addition to the Zoom sessions.

One overarching goal of ours is to have the community stay together during these difficult times and to feature some fascinating ideas and concepts in astronomy in the curriculum, said Du, who is joined by graduate student instructors at the classes. It also provides the participants with an opportunity to talk to experts and students in the field.

As part of the move to virtual, Dugdale said the audience has expanded beyond Riverside, with some participants joining from as far as the East Coast.

As a parent himself, Dugdale said he wanted to provide parents a safe and engaging space for their children while also giving them a break a few hours a week.

We wanted to support campus, families, and the further-away communities, particularly with the stress families have been going through with school and life in general, he said.

Read more here:

Recreation Services finds success with virtual programming - UC Riverside

Heres what the biggest giant planet in our solar system, Jupiter, looks like. The Juno spacecraft captured this image during its 31st close flyby of Jupiter on December 30, 2020. The storm known as the Great Red Spot is visible on the horizon, nearly rotated out of view. Citizen scientist Tanya Oleksuik created this color-enhanced image using data from the JunoCam camera. Image via NASA.Our solar system is normal

In late May 2021, astronomers released new results in a 30-year census of planetary systems beyond our own. The results show that most are arranged much like our solar system. That is, most giant exoplanets arent close to their parent stars, but instead live in the suburbs of their systems. Thats contrary to what astronomers thought when first discovering giant exoplanets in the 1990s. For awhile, they thought hot Jupiters giant planets close to their stars might be the norm. Now the California Legacy Survey, which began in the 1990s, has proven otherwise. The newly released census results describe our solar system as normal. Or, as astronomer Andrew Howard of Caltech said in a statement:

Were starting to see patterns in other planetary systems that make our solar system look a bit more familiar.

The results were published on May 25, 2021, in two studies (here and here) in the peer-reviewed Astrophysical Journal Supplement.

Our solar system is arranged with the rocky, terrestrial planets closest to our sun and the gas giant planets farther out. Astronomers typically speak of distances in planetary systems in astronomical units (AU). One AU is the same as Earths distance from the sun, or 93 million miles (150 million km). Jupiter lies 5 AU from our sun. Saturn lies 9 AU from our sun. The survey showed that giant exoplanets mostly live within 1 and 10 AU from their parent stars.

Giant planets have a big impact on the formation of their planetary systems. Astronomer Lauren Weiss of the University of Hawaii Institute for Astronomy commented:

Dynamically speaking, Jupiter and Saturn are the VIPs Very Important Planets of the solar system. They are thought to have shaped the assembly of the terrestrial planets, potentially stunting the growth of Mars and slingshotting water-bearing comets toward Earth.

Astronomers didnt begin finding planets orbiting distant stars until the 1990s. They often find the largest gas giant planets because these planets are so massive. On the other hand, the California survey was unable to include smaller gas giant planets in the range of Uranus (19 AU) and Neptune (30 AU). They were able to note that planets the size of Jupiter and Saturn were uncommon as far out as Uranus and Neptune, however. BJ Fulton of Caltech explained:

While we cant detect smaller planets similar to Neptune and Uranus that are very distant from their stars, we can infer that the large gas giants like Jupiter and Saturn are extremely rare in the outermost regions of most exoplanetary systems.

The survey data reveal that for every 100 stars in our Milky Way galaxy, there are likely to be at least 14 cold giant planets. We dont know for sure how many stars our Milky Way contains, but its probably between 100 and 400 billion stars. Extrapolating from the number of giant planets detected around nearby stars, astronomers believe the Milky Way galaxy teems with billions of giant planets.

The survey targeted 719 sunlike stars for more than 30 years. It analyzed 177 planets, including 14 newly discovered gas giants. The planets have masses between 1/100 and 20 times the mass of Jupiter. (For comparison, Jupiter is 318 times as massive as Earth. In fact, Jupiters mass is 2.5 times that of all the other planets in our solar system combined.)

The team designed the survey to be unbiased by selecting random stars. Lee Rosenthal of Caltech explained they chose the survey members:

As if you could put your hand in a grab bag of stars and pull a random planet out.

When astronomers first began discovering exoplanets in the 1990s, they wondered if our solar system was unusual. That was because most of the first planets to be discovered were hot Jupiters, similar in mass to Jupiter but orbiting very close (less than 1 AU) to their parent stars. But, as it turns out, one of the primary methods used to discover exoplanets was biased in favor of finding these large and close-in planets. That planet-hunting method, called radial velocity method, watches for a wobble in a stars motion produced by the tug of a planet. And, of course, nearby giant planets tugged the hardest. Rosenthal said:

The hot Jupiters were easy pickings back then, but those early surveys were biased and didnt get the full picture.

The span of 30-some years since then has improved planet-hunting technologies. Now astronomers can detect a stars wobble from a planet orbiting far from it. And so the long-term California Legacy Survey has produced a wide range of results. As Fulton said:

The idea is to survey planets of all sizes and temperatures and then to look for patterns in the data.

The team is looking forward to new instruments that will help them see more and learn more about distant exoplanets. One instrument is the Keck Planet Finder, which may be ready as soon as 2022. The Keck Planet Finders main goal will be to measure the masses and orbital properties of small planets including Earths, super-Earths, and sub-Neptunes. The Planet Finders principal investigator is Andrew Howard of Caltech. He said:

This survey is a great jumping-off point for future instruments that are sensitive to planets the size of Earth.

Bottom line: Astronomers released the results of a 30-plus-year survey of exoplanets that found that giant planets live at a similar distance from their host star as we see here in our own solar system.

Source: The California Legacy Survey I. A Catalog of 177 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades

Source: The California Legacy Survey II. Occurrence of Giant Planets Beyond the Ice line

Via Caltech

Via Keck Observatory

Kelly Kizer Whitt has been a science writer specializing in astronomy for more than two decades. She began her career at Astronomy Magazine, and she has made regular contributions to AstronomyToday and the Sierra Club, among other outlets. Her childrens picture book, Solar System Forecast, was published in 2012. She has also written a young adult dystopian novel titled A Different Sky. When she is not reading or writing about astronomy and staring up at the stars, she enjoys traveling to the national parks, creating crossword puzzles, running, tennis, and paddleboarding. Kelly lives with her family in Wisconsin.

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Giant planets live in the suburbsGiant planets live in the suburbs - EarthSky