Astronomical Distance Scales

Some Common Distance Units: Light Year: the distance that light travels in one year (9.46 x 10^17 cm). Parsec (pc): 3.26 light years (or 3.086 x 10^18 cm).; also kiloparsec (kpc) = 1000 parsecs and megaparsec (Mpc) = 1,000,000 parsecs. Astronomical Unit (AU): the average separation of the earth and the sun (1.496 x 10^13 cm). Some Representative Distances: The Solar System is about 80 Astronomical Units in diameter. The...

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Hubble's constant (Hubble's Law)

The Hubble constant H is one of the most important numbers in cosmology because it may be used to estimate the size and age of the Universe. Hubble constant indicates the rate at which the universe is expanding. Although the Hubble "constant" is not really constant because it changes with time (and therefore should probably more properly be called the "Hubble parameter"). The Hubble constant is often written with a subscript "0"...

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What are the smallest particles in the Universe?

For many years, the only known subatomic particles were protons, neutrons and electrons. By the 1960s, however, advancements in particle accelerator technology had shown evidence of hundreds of smaller constituent particles. By studying these particles -- all part of what is known in particle physics theory as the standard model -- physicists can try to explain all of the forces and matter existing in the universe. These smallest...

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Astronomy - August 2013 (40th Anniversary Issue)

Look forward to studying the starry night sky? Revel in seeing if you can locate and connect the Big Dipper and the brightest North star? If you're a star gazing enthusiast, you'll love Astronomy. You'll learn more about exploring the universe in your own backyard with the most popular amateur astronomy magazine. Astronomy - August 2013 (no ADS) 40th Anniversary Issue English | PDF | 83 pages | 36.6 MB FEATURES :- 26 COVER...

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Is the sun dying?

Without sun's existence, there wouldn't be life on Earth. In the grand scheme of things, however, our sun is simply another star among star among the other hundreds of billions of stars in the universe.Officially, the Sun is a class G2V star- in other words,a main-sequence yellow dwarf have a temperature range of 5,000 to 6,000 degrees Celsius and their mass is about 80-120 percent of the mass of the sun. That means that the Sun is...

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What are Saturn’s Rings Made Of?

Saturn's rings are made of billions of pieces of ice, dust and rocks. Some of these particles are as small as a grain of salt, while others are as big as houses. These chucks of rock and ice are thought to be pieces of comets, asteroids or even moons which were torn apart by the strong gravity of Saturn before they could reach the planet. Galileo Galilei was the first to observe the rings of Saturn in 1610 using his telescope,...

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How the Seasons Work?

It turns out that the elliptical orbit of the Earth has little effect on the seasons. Instead, it is the 23.45-degree tilt of the planet's rotational axis that causes us to have winter and summer. The diagram below demonstrates what happens. In this diagram, you can see the axis of rotation and the equator. The Northern Hemisphere (at the top) is currently experiencing winter, and the Southern Hemisphere is experiencing summer....

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How do orbits work?

We might take it for granted, but why do stars, moons, planets or any celestial bodies constantly move around one another?  What an Orbit Really Is The drawings at the right simplify the physics of orbiting Earth. We see Earth with a huge, tall mountain rising from it. The mountain, as Isaac Newton first envisioned, has a cannon at the top. When the cannon is fired, the cannonball follows its ballistic arc, falling...

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When does sky become space?

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 The Kármán line (Karman line) is an official boundary between the Earth’s atmosphere and space, lying 100km (approximately 62 miles) above sea level. The governing body for air sports and aeronautical world records, Federation...

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Astronomy - July 2013

The world's best-selling astronomy magazine offers you the most exciting, visually stunning, and timely coverage of the heavens above. Each monthly issue includes expert science reporting, vivid color photography, complete sky coverage, spot-on observing tips, informative telescope reviews, and much more! All this in an easy-to-understand, user-friendly style that's perfect for astronomers at any level. Hardcover: 80 pages File...

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Physics for Scientists and Engineers with Modern Physics (9th Ed)

Book Details: Hardcover: 1622 pages Publisher: Cengage Learning; 9 edition (January 17, 2013) Language: English ISBN-10: 1133954057 ISBN-13: 978-1133954057 File Size: 45.0 Mb | File Format: PDF Book Description: Achieve success in your physics course by making the most of what PHYSICS FOR SCIENTISTS AND ENGINEERS WITH MODERN PHYSICS has to offer. From a host of in-text features to a range of outstanding technology resources,...

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Time,Space,Stars and Man-The Story of the Big Bang

Hardcover: 496 pages Publisher: World Scientific Publishing Company (April 2009) Language: English ISBN-10: 1848162723 ISBN-13: 978-1848162723 Most well-read, but non-scientific, people will have heard of the term 'Big Bang' as a description of the origin of the Universe. They will recognize that DNA identifies individuals and will know that the origin of life is one of the great unsolved scientific mysteries. This book brings...

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Space - From Earth to the Edge of the Universe

Hardcover: 360 pages Publisher: DK Publishing (October 4, 2010) Language: English Featuring a wealth of incredible astronomical photographs, Space is perfect for anyone interested in astronomy, space imagery, and the history of space exploration. Space takes us on an imaginary journey that starts on a launch pad, goes toward the center of our Solar System to see the inner planets and the Sun, and then flies outward past the outer...

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Astronomy for Entertainment (by Yakov Perelman)

Astronomy is a fortunate science; it needs no embellishments, said the French savant Arago. So fascinating are its achievements that no special effort is needed to attract attention. Nonetheless, the science of the heavens is not only a collection of astonishing revelations and daring theories. Ordinary facts, things that happen, day by day, are its substance. Most laymen have, generally speaking, a rather hazy notion of...

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Clown Face Nebula (Eskimo Nebula)

A planetary nebula, also known as the Eskimo Nebula, in the constellation Gemini, position RA 07 h 29.2 m, dec. +20◦ 55 . It is bluish, 13" in diameter, and of ninth magnitude, with a tenth-magnitude central star. The bluegreen nebula’s hazy outer regions are thought to resemble an Eskimo’s hood or clown’s ruff. The formation resembles a person's head surrounded by a parka hood. It is surrounded by gas that composed the outer layers...

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Gum Nebula discovered by C S Gum

Gum, Colin (1924–60) - Australian radioastronomer, mapped the southern sky for radio sources and emission nebulae, and discovered the Gum Nebula in the Vela Puppis region. Gum Nebula - A very large, near-circular emission nebula, approximately 36◦ in diameter, in the constellations Puppis and Vela. The largest known nebula in the sky, it was discovered by the Australian astronomer C S Gum (1924–60), and is believed to be an ancient...

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Crab Nebula

The Crab Nebula is a supernova remnant and pulsar wind nebula in the constellation of Taurus. Corresponding to a bright supernova recorded by Chinese astronomers in 1054, the nebula was observed later by John Bevis in 1731. The Crab Nebula was first identified in 1731 by John Bevis. The nebula was independently rediscovered in 1758 by Charles Messier as he was observing a bright comet It was named by Lord Rosse for its superficial...

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Orion Nebula Discovered by Christiaan Huygens

The Orion Nebula is a diffuse nebula situated south of Orion's Belt in the constellation of Orion. It is seen as the middle "star" in the sword of Orion, which are the three stars located south of Orion's Belt. It is one of the brightest nebulae, and is visible to the naked eye in the night sky. There are supersonic "bullets" of gas piercing the hydrogen clouds of the Orion Nebula. Each bullet is ten times the diameter of Pluto's orbit...

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Horsehead Nebula discover by Williamina Fleming

The Horse Head Nebula (also known as Barnard 33 in bright nebula IC 434) takes its name from the horse head shape in its middle. The first human to discover it was Williamina Fleming in 1888 at Harvard University. It is one of the most identifiable nebulae because of the shape of its swirling cloud of dark dust and gases, which bears some semblance to a horse's head when viewed from Earth. The Horsehead Nebula is a dark nebula...

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