Monthly Archives: July 2017

Astronomy is a natural science. It is the study of everything outside the atmosphere of Earth.

It studies celestial objects (such as stars, galaxies, planets, moons, asteroids, comets and nebulae) and processes (such as supernovae explosions, gamma ray bursts, and cosmic microwave background radiation). This includes the physics, chemistry of those objects and processes.

A related subject, physical cosmology, is concerned with studying the Universe as a whole,[1] and the way the universe changed over time.

The word astronomy comes from the Greek words astron which means star and nomos which means law.[2] A person who studies astronomy is called an astronomer.

Astronomy is one of the oldest sciences. Ancient people used the positions of the stars to navigate, and to find when was the best time to plant crops. Astronomy is very similar to astrophysics. Since the 20th century there have been two main types of astronomy, observational and theoretical astronomy. Observational astronomy uses telescopes and cameras to observe or look at stars, galaxies and other astronomical objects. Theoretical astronomy uses maths and computer models to predict what should happen. The two often work together, the theoretical predicts what should happen and the observational shows whether the prediction works.

Astronomy is not the same as astrology, the belief that the patterns the stars and the planets may affect human lives.

Early astronomers used only their eyes to look at the stars. They used maps of the constellations and stars for religious reasons and also to work out the time of year.[3] Early civilisations such as the Maya people and the Ancient Egyptians built simple observatories and drew maps of the stars positions. They also began to think about the place of Earth in the universe. For a long time people thought Earth was the center of the universe, and that the planets, the stars and the sun went around it. This is known as the geocentric model of the Universe.

Ancient Greeks tried to explain the motions of the sun and stars by taking measurements.[4] A mathematician named Eratosthenes was the first who measured the size of the Earth and proved that the Earth is a sphere. A theory by another mathematician named Aristarchus was, that the sun is in the center and the Earth is moving around it. This is known as the Heliocentric model. Only a small group of people thought it was right. The rest continued to believe in the geocentric model. Most of the names of constellations and stars come from Greeks of that time.[5]

Arabic astronomers made many advancements during the Middle Ages including improved star maps and ways to estimate the size of the Earth.[6]

During the renaissance a priest named Nicolaus Copernicus thought, from looking at the way the planets moved, that the Earth was not the center of everything. Based on previous works, he said that the Earth was a planet and all the planets moved around the sun. This heliocentrism was an old idea. A physicist called Galileo Galilei built his own telescopes, and used them to look more closely at the stars and planets for the first time. He agreed with Copernicus. Their ideas were also improved by Johannes Kepler and Isaac Newton who invented the theory of gravity. At this time the Catholic Church decided that Galileo was wrong. He had to spend the rest of his life under house arrest.[7]

After Galileo, people made better telescopes and used them to see farther objects such as the planets Uranus and Neptune. They also saw how stars were similar to our Sun, but in a range of colours and sizes. They also saw thousands of other faraway objects such as galaxies and nebulae.

The 20th century saw important changes in astronomy.

In 1931, Karl Jansky discovered radio emission from outside the Earth when trying to isolate a source of noise in radio communications, marking the birth of radio astronomy and the first attempts at using another part of the electromagnetic spectrum to observe the sky. Those parts of the electromagnetic spectrum that the atmosphere did not block were now opened up to astronomy, allowing more discoveries to be made.

The opening of this new window on the Universe saw the discovery of entirely new things, for example pulsars, which sent regular pulses of radio waves out into space. The waves were first thought to be alien in origin because the pulses were so regular that it implied an artificial source.

The period after World War 2 saw more observatories where large and accurate telescopes are built and operated at good observing sites, normally by governments. For example, Bernard Lovell began radio astronomy at Jodrell Bank using leftover military radar equipment. By 1957, the site had the largest steerable radio telescope in the world. Similarly, the end of the 1960s saw the start of the building of dedicated observatories at Mauna Kea in Hawaii, a good site for visible and infra-red telescopes thanks to its high altitude and clear skies.

The next great revolution in astronomy was thanks to the birth of rocketry. This allowed telescopes to be placed in space on satellites.

Satellite-based telescopes opened up the Universe to human eyes. Turbulence in the Earth's atmosphere blurs images taken by ground-based telescopes, an effect known as seeing. It is this effect that makes stars "twinkle" in the sky. As a result, the pictures taken by satellite telescopes in visible light (for example, by the Hubble Space Telescope) are much clearer than Earth-based telescopes, even though Earth-based telescopes are very large.

Space telescopes gave access, for the first time in history, to the entire electromagnetic spectrum including rays that had been blocked by the atmosphere. The X-rays, gamma rays, ultraviolet light and parts of the infra-red spectrum were all opened to astronomy as observing telescopes were launched. As with other parts of the spectrum, new discoveries were made.

From 1970s satellites were launched to be replaced with more accurate and better satellites, causing the sky to be mapped in nearly all parts of the electromagnetic spectrum.

Discoveries broadly come in two types: bodies and phenomena. Bodies are things in the Universe, whether it is a planet like our Earth or a galaxy like our Milky Way. Phenomena are events and happenings in the Universe.

For convenience, this section has been divided by where these astronomical bodies may be found: those found around stars are solar bodies, those inside galaxies are galactic bodies and everything else larger are cosmic bodies.

Diffuse Objects:

Compact Stars:

Burst events are those where there is a sudden change in the heavens that disappears quickly. These are called bursts because they are normally associated with large explosions producing a "burst" of energy. They include:

Periodic events are those that happen regularly in a repetitive way. The name periodic comes from period, which is the length of time required for a wave to complete one cycle. Periodic phenomena include:

Noise phenomena tend to relate to things that happened a long time ago. The signal from these events bounce around the Universe until it seems to come from everywhere and varies little in intensity. In this way, it resembles "noise", the background signal that pervades every instrument used for astronomy. The most common example of noise is static seen on analogue televisions. The principal astronomical example is: Cosmic background radiation.

There are way astronomers can get better pictures of the heavens. Light from a distant source reaches a sensor and gets measured, normally by a human eye or a camera. For very dim sources, there may not be enough light particles coming from the source for it to be seen. One technique that astronomers have for making it visible is using integration, (which is like longer exposures in photography).

Astronomical sources do not move much: only the rotation and movement of the Earth causes them to move across the heavens. As light particles reach the camera over time, they hit the same place making it brighter and more visible than the background, until it can be seen.

Telescopes at most observatories (and satellite instruments) can normally track a source as it moves across the heavens, making the star appear still to the telescope and allowing longer exposures. Also, images can be taken on different nights so exposures span hours, days or even months. In the digital era, digitised pictures of the sky can be added together by computer, which overlays the images after correcting for movement.

With radio telescopes smaller telescopes can be combined together to create a big one, which works like one as big as the distance between the two smaller telescopes.

Adaptive optics means changing the shape of the mirror or lens while looking at something, to see it better.

Data analysis is the process of getting more information out of an astronomical observation than by simply looking at it. The observation is first stored as data. This data will then have various techniques used to analyse it.

Fourier analysis in mathematics can show if an observation (over a length of time) is changing periodically (changes like a wave). If so, it can extract the frequencies and the type of wave pattern, and find many things including new planets.

A good example of a fields comes from pulsars which pulse regularly in radio waves. These turned out to be similar to some (but not all) of a type of bright source in X-rays called a Low-mass X-ray binary. It turned out that all pulsars and some LMXBs are neutron stars and that the differences were due to the environment in which the neutron star was found. Those LMXBs that were not neutron stars turned out to be black holes.

This section attempts to provide an overview of the important fields of astronomy, their period of importance and the terms used to describe them. It should be noted that astronomy in the Modern Era has been divided mainly by electromagnetic spectrum, although there is some evidence this is changing.

Solar astronomy is the study of the Sun. The Sun is the closest star to Earth at around 92 million (92,000,000) miles away.[8] It is the easiest to observe in detail. Observing the Sun can help us understand how other stars work and are formed. Changes in the Sun can affect the weather and climate on Earth. A stream of charged particles called the Solar wind is constantly sent off from the Sun. The Solar Wind hitting the Earth's magnetic field causes the northern lights.[9] Studying the Sun helped people understand how nuclear fusion works.

Planetary Astronomy is the study of planets, moons, dwarf planets, comets and asteroids as well as other small objects that orbit stars. The planets of our own Solar System have been studied in depth by many visiting spacecraft such as Cassini-Huygens (Saturn) and the Voyager 1 and 2.

Galactic Astronomy is the study of distant galaxies. Studying distant galaxies is the best way of learning about our own galaxy, as the gases and stars in our own galaxy make it difficult to observe. Galactic Astronomers attempt to understand the structure of galaxies and how they are formed through the use of different types of telescopes and computer simulations.

Hydrodynamics is used in astronomy for mathematically modelling how gases behave. Strong magnetic fields found around many bodies can drastically change how these gases behave, affecting things from star formation to the flows of gases around compact stars. This makes MHD an important and useful tool in astronomy.

Gravitational wave astronomy is the study of the Universe in the gravitational wave spectrum. So far, all astronomy that has been done has used the electromagnetic spectrum. Gravitational Waves are ripples in spacetime emitted by very dense objects changing shape, which include white dwarves, neutron stars and black holes. Because no one has been able to detect gravitational waves directly, the impact of Gravitational Wave Astronomy has been very limited.

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Astronomy - Simple English Wikipedia, the free encyclopedia

Learn about animals, astronomy and more scientific wonders at 6000 N. Flagler Drive, West Palm Beach.

A storied machine responsible for some of the greatest advances in modern astronomy, its 200-inch primary mirror set the size limit for five decades.

Yes, astronomy is typically extremely visual, but there are tons of ways to interact with data thats not visual at all.

Something else that makes this part of the country special, from an astronomy standpoint: Another total solar eclipse will swing by April 8, 2024.

The findings, described in a paper accepted to Physical Review Letters, cement the idea that gravitational-wave astronomy a whole new way to observe some of the most powerful events in the universe is here to stay.

Dr. Eugene Parker, from the University of Chicago's department of astronomy and astrophysics, debuts his Parker Solar Probe on May 31, 2017.

Yangs work stood out even among other excellent projects, said Len Duda, who just retired from the Sandia National Laboratories in Albuquerque, N.M., and served as a coach for the physics and astronomy division at the Intel competition.

This is the eighth annual Mall event that organizer Don Lubowich, astronomy outreach coordinator at Hofstra University, Hempstead, N.Y., has assembled.

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Astronomy | Definition of Astronomy by Merriam-Webster

30 June 2017 Astronomy Now

This orange blob shows the nearby star Betelgeuse, as seen by the Atacama Large Millimeter/submillimeter Array (ALMA). This is the first time that ALMA has ever observed the surface of a star and this first attempt has resulted in the highest-resolution image of Betelgeuse available.

Betelgeuse is one of the largest stars currently known with a radius around 1400 times larger than the Suns in the millimeter continuum. About 600 light-years away in the constellation of Orion (The Hunter), the red supergiant burns brightly, causing it to have only a short life expectancy. The star is just about eight million years old, but is already on the verge of becoming a supernova. When that happens, the resulting explosion will be visible from Earth, even in broad daylight.

The star has been observed in many other wavelengths, particularly in the visible, infrared, and ultraviolet. Using ESOs Very Large Telescope astronomers discovered a vast plume of gas almost as large as our Solar System. Astronomers have also found a gigantic bubble that boils away on Betelgeuses surface. These features help to explain how the star is shedding gas and dust at tremendous rates. In this picture, ALMA observes the hot gas of the lower chromosphere of Betelgeuse at sub-millimeter wavelengths where localised increased temperatures explain why it is not symmetric. Scientifically, ALMA can help us to understand the extended atmospheres of these hot, blazing stars.

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See the sharpest-ever view of giant Betelgeuse - Astronomy Now Online

On Monday, July 3 beginning at 7:30 p.m. join astronomers from Caltech for Astronomy on Tap.

At this event, youll learn about the supermassive black holes and weird planets in talks by Elena Murchikova: The Supermassive Black Hole at the Center of Our Galaxy and by Dr. Erik Petigura: Is Our Solar System Weird? In addition, they will host an astronomically-themed quiz with great space-related prizes for the winners.

Come with science questions, as there will be many world-renowned astronomers to mingle with between talks. In addition, Der Wolfskopf features a special Astronomy on Tap Happy Hour for discount prices on beer and food throughout the event.

Astronomy on Tap is a nation-wide phenomenon where professional astronomers give informal talks in local bars on a variety of scientific topics followed by lots of discussion and interaction with the public. Here in Los Angeles, we at Caltech are spearheading this effort in collaboration with researchers from UCLA, Carnegie, The Planetary Society, and the Jet Propulsion Laboratory (operated by Caltech for NASA).

The event is free and open to all ages 21+. Doors open at 4:00 p.m. For more information about our events and affiliated lecture+stargazing series visit http://www.astro.caltech.edu/outreach/aot.

Der Wolfskopf Pub is located at 72 N. Fair Oaks Avenue in Old Pasadena.

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Bring Your Thirst for Beer and Knowledge to Astronomy on Tap - Pasadena Now

(Daniel Zantzinger / Skywatcher's Guide)

It is perhaps indisputable that skywatching July's warm summer nights is the most comfortable, spectacular and awe inspiring outdoor activity going.

The trick, the essence of summer's night skywatching, lies in first rooting in the core concentration of stars in the south, and then slowly climbing the galactic arms toward zenith and beyond.

Whether you're using your eyes, binoculars, telescopes, scientific journals and/or telescope-directing websites, there's more than enough out there to stimulate the imagination, provoke wonder and astound the senses.

For many skywatchers, this is a great time to head away from the city lights into the hills; to the high country with its deep and darkened valleys; to our state parks and national monuments; and to someone else's sparsely populated, protected properties.

This is the season of the scorpion, the swan, the deeply troubled Hercules and myriad other sidereal (star-like) residents of the Milky Way. Moreover, each one of these house crystalline and nebulous denizens of their own, who in turn hold in their embraces secrecies unfolded only to skywatchers making the effort to look for them.

Find fishhook-shaped Constellation Scorpius, "the scorpion," low and due south at 11 tonight (July 1) and around nightfall on the 31st. To its east is teapot-shaped Constellation Sagittarius, "the centaur archer," and to its north is Constellation Ophiuchus, "the serpent-bearer." Saturn, having reached opposition just two weeks ago, is well positioned here for viewing until the end of August.

These areas of space are so rich that if you figuratively speaking were to draw your last breath right after careful and thorough examination of them, you will have died having a life fulfilled with few regrets.

The moon is bright here in the month's first 10 days or so, so it's best to get serious July 16 and thereafter.

Darker skies mean better views. Longer expanses of time between ocular exposures to white light after a minimum of 12 minutes mean better viewing ability. Use red flashlights. Avoid looking at car headlights, or you'll have to start the clock all over again. A good dose of Zen patience and measured breathing provides for you a better overall experience. Speak minimally, and your companions will have a better overall experience.

When you're staring at Sagittarius, you're gazing in the direction of the galactic core, that is, toward the center of the Milky Way. Most of the wow factor in the southern sky is from here toward zenith.

From our line of sight, three arms of the spiral barred (striped) galaxy intersect at the Scorpius/Sagittarius border. This allows us to observe not only millions of stars, but also diffuse nebulae M8, M17 and M20; and the relatively young and open star clusters M6, M7, M21, M23 and M25 circulating with the disc. These clusters have a few hundred to several thousand stars.

Scorpius and Sagittarius and our southern sky's hemisphere for that matter is home to an abundance of globular star clusters, spherical concentrations of several hundreds of thousands of much older and denser stars that dwell in the galaxy's outer halo.

With the naked eye, find red giant star Antares, the "rival of Mars," the heart of the scorpion, an irregular star that slowly pulses from magnitude 0.6 to 1.6. Train the telescope 1.3 degrees west to M4 to find one of the two closest globular clusters to the solar system.

Clocking in at 12.2 billion years old, M4 has some 13 billion-year-old white/degenerate dwarf stars invisible to earthbound skywatchers that are among the oldest known stars in the Milky Way galaxy. In 1995, the Hubble Space Telescope photographed white dwarf PSR B1620-26 with a planet with a mass of 2.5 times that of Jupiter.

With binoculars and/or a motorized telescope, crawl up the galaxy's arms into Constellation Cygnus, "the swan,"to the Great Globular Cluster (M13) in Constellation Hercules at zenith, and then into the great beyond.

The moon is full at 10:07 p.m. July 8, and is called the Full Thunder Moon.

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Astronomy: July is the season of Scorpius - Longmont Times-Call