naseem
عدد الرسائل : 142 العمر : 31 البلد : سوريا تاريخ التسجيل : 24/01/2008
| موضوع: The Nearest Stars الإثنين 23 مارس 2009 - 21:51 | |
| This map shows all the star systems that lie within 12.5 light years of our Sun. Most of the stars are red dwarfs - stars with a tenth of the Sun's mass and less than one hundredth the luminosity. Roughly eighty percent of all the stars in the universe are red dwarfs, and the nearest star - Proxima - is a typical example. Information on the 5 Nearest Stars - Sun Type=G2, Magnitude=-26.8, Distance=0.0000158 ly A typical yellow dwarf star. It has eight planets orbiting it.
Proxima Centauri - type=M5, Magnitude=11.0, Distance=4.22 ly This dim red dwarf is the nearest star to the Sun, and it is a member of the Alpha Centauri system despite lying 0.24 light years from the main pair of stars, requiring over one million years to orbit them. Proxima was discovered in 1915 by Robert Innes and was at that time the least luminous star known. It is also a flare star - capable of brightening a magnitude or more in minutes.
Alpha Centauri A,B - Type=G2+K0, Magnitudes=0.0+1.4, Distance=4.39 ly Just slightly further from us than Proxima, lie the orange and yellow dwarf stars that make up Alpha Centauri. Orbiting each other in an 80 year period, together they make up one of the brightest objects in southern hemisphere skies. Seen from Alpha Centauri, the third member of the system, Proxima, is a dim (magnitude 4.8 ) star.
Barnard's Star Type=M5, Magnitude=9.6, Distance=5.94 ly Famous for having the largest proper motion of any star, this dim red dwarf travels 0.29 degrees against the background sky in a century. Discovered by E Barnard in 1916, it was thought in the 1960's to have a couple of unseen planets orbiting it, but later observations disproved this. In another 8000 years Barnard's Star will become the closest star to us.
Wolf 359 - Type=M6, Magnitude=13.5, Distance=7.80 ly An excessively dim red dwarf discovered by Max Wolf in 1918. For 25 years it was the least luminous star known.
for more information : http://www.atlasoftheuniverse.com/index.html | |
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naser-sy
عدد الرسائل : 393 العمر : 35 البلد : syria-qamishly تاريخ التسجيل : 02/09/2007
| موضوع: رد: The Nearest Stars السبت 4 يوليو 2009 - 23:12 | |
| thanx naseem | |
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Mahmoud Alamir
عدد الرسائل : 949 العمر : 36 البلد : Syria تاريخ التسجيل : 20/02/2008
| موضوع: رد: The Nearest Stars الأحد 12 يوليو 2009 - 14:03 | |
| great.......thanks naseem | |
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محمد كرم الحمصي
عدد الرسائل : 208 العمر : 28 البلد : دمشق ضاحية قدسيا تاريخ التسجيل : 14/09/2009
| موضوع: رد: The Nearest Stars الأربعاء 6 يناير 2010 - 0:06 | |
| thank you for all this information | |
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