Clipmarks | invictus's 'astronomy' clips

Milky Way ringed by 'missing galaxies'

Sat, 20 Sep 2008 19:06:46 GMT

clipped by: invictus

SYDNEY: The Milky Way could be surrounded by up to 2,000 small galaxies, too faint to be seen with current technology, say astrophysicists.

Their research has implications for understanding how galaxies form and the nature of dark matter – the invisible matter that pervades and surrounds all galaxies, including our own.

Astronomers know of 24 satellite galaxies of the Milky Way, including the two bright Magellanic Clouds, which on dark nights are visible just to the side of the wide band of the Milky Way.

But the U.S. researchers, led by astrophysicist Erik Tollerud from the University of California, Irvine, say there are at least 400 and as many as 2,000 more satellite galaxies – we just haven't spotted them yet because they are so faint.

Tags: galaxies, milky way, astronomy, science

Distant object found orbiting Sun backwards

Sat, 06 Sep 2008 01:40:05 GMT

clipped by: invictus

Clip Source: space.newscientist.com

An object in the icy Kuiper belt has been found orbiting the Sun backwards, compared to most other objects in the solar system. It may help explain the origin of an enigmatic family of comets typified by Comet Halley.

The new object, called 2008 KV42, lies in the Kuiper belt, a ring of icy bodies beyond Neptune. Its orbit is inclined 103.5° to the plane of the Earth's orbit, or ecliptic. That means that as it orbits the Sun, it actually travels in the opposite direction to the planets.

Researchers led by Brett Gladman of the University of British Columbia first spotted the maverick object in May. Observations suggest it is about 50 kilometres across and travels on a path that takes it from the distance of Uranus to more than twice that of Neptune (or between 20 and 70 astronomical units from the Sun, with 1 AU being the Earth-Sun distance).

ts orbit appears to have been stable for hundreds of millions of years, but astronomers say it may have been born elsewhere.

Tags: astronomy, space, kuiper belt, comets, asteroids, solar system, science

Astronomers see 'youngest planet'

Wed, 02 Apr 2008 13:25:07 GMT

clipped by: invictus

Clip Source: news.bbc.co.uk

An embryonic planet detected in a far off galaxy could be less than 2,000 years old, astronomers say.

The ball of dust and gas, which is in the process of turning into a Jupiter-like giant, was detected around the star HL Tau by a UK team.

Research leader Dr Jane Greaves said the planet's growth may have been kickstarted when another young star passed the system 1,600 years ago.

Details were presented at the UK National Astronomy Meeting in Belfast.

The scientists studied a disc of gas and rocky particles around HL Tau, which is 520 light-years away and thought to be less than 100,000 years old.

But there is an intriguing suggestion that the gas giant, which is some 14 times the size of Jupiter, could be even younger.

Tags: planets, universe, astronomy, cosmology, science

Colossal tail trails dying star

Wed, 15 Aug 2007 22:49:59 GMT

clipped by: invictus
clipper's remarks:

"The fact that Mira's tail only glows with ultraviolet light might explain why other telescopes have missed it."

Clip Source: news.bbc.co.uk

A distant star that hurtles through space at extraordinary speeds has a huge, comet-like tail trailing in its wake, astronomers say.

The appendage, which measures a colossal 13 light years in length, was spotted by Nasa's Galaxy Evolution Explorer (Galex) space telescope.

The researchers said that nothing like it had ever been spotted around a star.

They believe the star, known as Mira, will help them to study what happens as stars meet their demise.

Mira (also called Mira A) has captivated astronomers for more than 400 years.

It sits about 350 light-years from Earth in a constellation known as Cetus, and is accompanied in orbit by a smaller secondary star, called Mira B, forming a binary system.

Billions of years ago, Mira would have been much like our Sun, but as it now enters its death-throes it has swollen into a type of star known as a red giant.

Yet despite centuries of study, its spectacular tail had remained undetected.

Tags: astronomy, space, mira, cetus, binary stars, science

'Hundreds of worlds' in Milky Way

Mon, 18 Feb 2008 01:52:48 GMT

clipped by: invictus

Clip Source: news.bbc.co.uk

Scientists say there may be many more worlds in our solar system

Rocky planets, possibly with conditions suitable for life, may be more common than previously thought in our galaxy, a study has found.

New evidence suggests more than half the Sun-like stars in the Milky Way could have similar planetary systems.

There may also be hundreds of undiscovered worlds in outer parts of our Solar System, astronomers believe.

Future studies of such worlds will radically alter our understanding of how planets are formed, they say.

New findings about planets were presented at the American Association for the Advancement of Science (AAAS) in Boston.

Tags: astronomy, space, milky way, galaxies, life, science

Asteroid flyby today - no impact risk

Tue, 29 Jan 2008 12:27:52 GMT

clipped by: invictus

Clip Source: www.spaceweather.com

Asteroid 2007 TU24 is flying past Earth today. There's no danger of a collision, but the 250m-wide space rock is close enough (1.4 lunar distances) to photograph through backyard telescopes as it speeds through the constellation Cassiopeia glowing like a 10th magnitude star. NASA radars are monitoring the flyby and may produce new images of the rock by week's end. [ephemeris] [3D orbit]

Tags: astronomy, science, asteroids, space, solar system

Close Encounter with Mars

Mon, 17 Dec 2007 23:56:56 GMT

clipped by: invictus

Clip Source: spaceweather.com

Ready your telescopes! On Tuesday evening, Dec. 18th, Mars makes its closest approach to Earth until the year 2016. At a distance of only 55 million miles, Mars outshines every star in the night sky (it is slightly brighter than Sirius) and draws attention to itself with its distinctive red color. Plus, it looks great through a backyard telescope:

Tags: astronomy, planets, backyard astronomy, mars, science

Galaxy is 'blasted' by black hole

Mon, 17 Dec 2007 20:35:34 GMT

clipped by: invictus

Clip Source: news.bbc.co.uk

A powerful jet of particles from a "supermassive" black hole has been seen blasting a nearby galaxy, according to findings from the US space agency.

Galaxies have been seen colliding before, but this is the first time this type of galactic violence has been seen by astronomers.

This could have a profound effect on any planets in the jet's path and could also trigger a burst of star formation.

The findings are to be published in the Astrophysical Journal.

They were obtained using Nasa's space-based Chandra X-ray Observatory, its Hubble Space Telescope, and Spitzer Space Telescope, as well as the Very Large Array (VLA) and Merlin radio telescopes on the ground.

Tags: universe, galaxies, collision, astronomy, black hole, science

A new and large sunspot at last

Sat, 08 Dec 2007 15:27:29 GMT

clipped by: invictus

Clip Source: spaceweather.com

Sunspot 978 popped over the sun's eastern limb on Dec. 6th and it has quickly become one of the largest sunspots of the year. Pete Lawrence of Selsey UK photographed the active region yesterday:

"The image was taken through a Coronado Calcium-K PST," says Lawrence. "Its nice to see something tangible crossing the solar disk again." Sunspot 978 poses no threat for strong solar flares but this could change if its rapid growth continues. Stay tuned!

Tags: sun, astronomy, sunspots, science

Space Balls. An accurate model of Planets to Sun etc

Fri, 16 Jun 2006 17:57:41 GMT

clipped by: sohil

Clip Source: webisto.com

Tags: science, space, photoshop, planets, sun, astronomy

"Exploding Comet" Photo Gallery

Sun, 11 Nov 2007 17:20:07 GMT

clipped by: invictus
clipper's remarks: Many good shots of Comet 17P/Holmes, taken by backyard astronomers around the world.

Clip Source: spaceweather.com

Summary: Comet 17P/Holmes shocked astronomers on Oct. 24, 2007, with a spectacular eruption. In less than 24 hours, the 17th magnitude comet brightened by a factor of nearly a million becoming a naked-eye object in the evening sky. Look for a golden 2.5th magnitude fuzzball in the constellation Perseus after sunset.

Tags: astronomy, comets, comet holmes, images, photography

Exploding Comet update - New images

Mon, 29 Oct 2007 22:55:08 GMT

clipped by: invictus

Clip Source: spaceweather.com

Exploding Comet 17P/Holmes is now larger than Jupiter. Astronomer Eric Allen of Quebec's Observatoire du Cégep de Trois-Rivières combined images he captured on three consecutive nights (Oct. 25, 26 and 27) and placed them beside a picture of Jupiter scaled to the same distance as the comet:

The diaphanous and curiously spherical cloud surrounding the comet's core is now large enough to physically swallow the King of Planets!

And that's just for starters. The growing comet subtends an angle (4 arcminutes) as large as the Moon's Sea of Tranquillity. Last night in Higham Ferrers, England, Dave Eagle photographed "the Moon and Comet Holmes with the same setup to show how big this strange comet is."

Although the comet is not as bright as Jupiter or a lunar mare, it is visible to the unaided eye. Look north after sunset for a magnitude +2.5 fuzzball in the constellation Perseus: sky map.

Tags: astronomy, comets, exploding comet, images, science

Erupting comet brightens up the sky

Wed, 24 Oct 2007 20:36:07 GMT

clipped by: invictus
clipper's remarks: Astronomers in Japan and Europe report that Comet 17P/Holmes is undergoing a spectacular eruption. The 17th-magnitude comet has brightened by a factor of five hundred thousand or more during the past 24 hours becoming a naked eye object in the evening sky.

Clip Source: www.astro.uni-bonn.de

A most amazing eruption is occuring on comet 17P/Holmes which was at 17 mag. at best but on October 24 suddenly began to brighten like crazy: Now (afternoon UTC) it has already reached 3rd magnitude and is easily visible to the naked eye, as reports from Japan indicate: "Perseus does not look 'Perseus' familiar to us due to the bright stellar object now."

The comet looks like a bright, yellow star, and only magnification reveals a fuzzy coma around the dusty core. Holmes was discovered in 1892 thanks to a similar outburst, and hope is that the further development will be similar now: the coma should expand over time but stay bright for a week or more.

Tags: astronomy, comets, science

Radio burst from space mystifies astronomers

Sat, 29 Sep 2007 01:08:42 GMT

clipped by: invictus

Clip Source: news.yahoo.com

Astronomers who stumbled upon a powerful burst of radio waves said on Thursday they had never seen anything like it before, and it could offer a new way to search for colliding stars or dying black holes.

They were searching for pulsars -- a type of rotating compacted neutron star that sends out rhythmic pulses of radiation -- when they spotted the giant radio signal.

It was extremely brief but very strong, and appears to have come from about 3 billion light-years away -- a light-year being the distance light travels in a year, or about 6 trillion miles.

"This burst appears to have originated from the distant universe and may have been produced by an exotic event such as the collision of two neutron stars or the death throes of an evaporating black hole," said Duncan Lorimer of West Virginia University and the National Radio Astronomy Observatory.

Tags: astronomy, pulsars, radio signals, science

Star catalogue revised & refined

Sat, 29 Sep 2007 01:04:00 GMT

clipped by: invictus

Clip Source: news.bbc.co.uk

Hipparcos' data underpins the system of cosmic measurement

The most accurate catalogue of the distances to more than 100,000 stars has just been released.

Cambridge astronomer Dr Floor van Leeuwen has spent the past 10 years checking and recalculating data gathered by the Hipparcos satellite.

It collected the information in the 1990s, but questions were raised about apparent errors in the results.

Dr van Leeuwen, who saw a flaw in the way Hipparcos worked, has now corrected the star distances.

The catalogue (Hipparcos - The New Reduction of the Raw Data) will allow astronomers to probe more deeply into the properties of stars and galaxies.

Astronomers can only determine the physical properties of stars by comparing their luminosity with their distance from Earth. Without an accurate measurement of distance, the star's true luminosity or size cannot be known.

Tags: astronomy, stars, hipparcos, stars catalogue, science