13
Jan 10

Formation of massive planets in binary star systems

Source: arXiv


Sunset on a planet of a binary system. Credit:NASA.

Over the last years 40 planetary systems have been discovered surounding binary star systems. In all cases the configuration appears to be circumstellar, where the planets orbit around one of the stars, the secondary acting as a disturber. This could have happened in our own solar system if Jupiter was much bigger than it actually is.

The formation of planets in the binary star systems is more difficult than around single stars due to the gravitational action of the companion on the dynamics of the protoplanetary disk. Wiley Kley has presented relevant observational evidence that planets can really exist in in binary systems. (read more)

Link:

arXiv-Kley, W.(2009) Extrasolar Planets in Multi-body Systems: Theory and Observations, Editors: K. Gozdziewski, A. Niedzielski and J. Schneider, EAS Publications Series.

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13
Jan 10

VLT Captures First Direct Spectrum of an Exoplanet

Source: ESO Science Release 02/10

ESO has just released the magnificent information that the VLT has been capable, for the first time in human, to provide data that allows the study of an exoplanet's atmosphere.

By studying a triple planetary system that resembles a scaled-up version of our own Sun’s family of planets, astronomers have been able to obtain the first direct spectrum — the “chemical fingerprint” — of a planet orbiting a distant star, thus bringing new insights into the planet's formation and composition. The result represents a milestone in the search for life elsewhere in the Universe. (read more)

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13
Jan 10

Orion - a signpost in the sky

Orion is an excellent constellation to use as a starting point to find some interesting objects in the sky. Draw an imaginary line through the three stars that make up the belt; now follow this line downwards (bottom left) and you should come to an extremely bright star – in fact it’s the brightest star in the sky and it’s name is Sirius or “the dog star”, it is in the constellation of The Great Hunting Dog. Not only is Sirius very bright, but it is also one of our closest stars.

If you follow your imaginary line upwards (top right) you will come across another very bright star, this time it’s Aldeberan in the constellation of Taurus, the Bull. If you continue the imaginary line you will come across what looks like at first a small cloud, if you look carefully you should be able to see six (or if you have a really dark sky) seven stars, this is an open star cluster called the Pleiades or the Seven Sisters – with a pair of binoculars you should be able to see 20 or so stars.
Another imaginary line left (eastwards) across the two shoulder stars indicates the direction of Procyon in the Small Hunting Dog, and a final line from Rigel through Betelgeuse points to Castor and Pollux the two main stars of the constellation of Gemini or the Twins.
You should now be able to find 7 of the brightest stars in the sky and one of the most impressive open star clusters.

Have fun!

Image credit: Wikipedia
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13
Jan 10

Orion - a signpost in the sky

Orion is an excellent constellation to use as a starting point to find some interesting objects in the sky. Draw an imaginary line through the three stars that make up the belt; now follow this line downwards (bottom left) and you should come to an extremely bright star – in fact it’s the brightest star in the sky and it’s name is Sirius or “the dog star”, it is in the constellation of The Great Hunting Dog. Not only is Sirius very bright, but it is also one of our closest stars.
If you follow your imaginary line upwards (top right) you will come across another very bright star, this time it’s Aldeberan in the constellation of Taurus, the Bull. If you continue the imaginary line you will come across what looks like at first a small cloud, if you look carefully you should be able to see six (or if you have a really dark sky) seven stars, this is an open star cluster called the Pleiades or the Seven Sisters – with a pair of binoculars you should be able to see 20 or so stars.
Another imaginary line left (eastwards) across the two shoulder stars indicates the direction of Procyon in the Small Hunting Dog, and a final line from Rigel through Betelgeuse points to Castor and Pollux the two main stars of the constellation of Gemini or the Twins.
You should now be able to find 7 of the brightest stars in the sky and one of the most impressive open star clusters.

Have fun!

Image credit: Wikipedia
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