Smallest star ever detected

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Lucas, Mar 5, 2005.

  1. Lucas Registered Senior Member

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  3. Lucas Registered Senior Member

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    "it is just 16% larger than Jupiter. This is smaller than some known planets found beyond our solar system - or exoplanets."

    The article affirms that is a star, not a brown dwarf, that could seem plausible. I wonder what place can have this little star in the HR diagram. the picture seems to indicate that is a red dwarf. Perhaps we should invent a new category to accomodate this star
     
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  5. blobrana Registered Senior Member

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    Hum,
    OGLE-TR-122b is a M-dwarf star, the density is more than 50 times greater (M=0.092±0.009 Mo) than that of our own Sun.
    (we know this cos` it transits around its solar-type primary every 7.3-days. )

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  7. Avatar smoking revolver Valued Senior Member

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    What I'd like to see is a star system consisting entirely of stars. I mean, one central star and many such dwarf stars orbiting it, just for the sights of it.
     
  8. Lucas Registered Senior Member

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    Multiple stellar systems do really exist, and in the observable universe there are at least 7*(10^22) stars, so the possibility of a system of the kind you say to exist is reasonable. I'd like very much to live in a planet with not only a Sun, but 5 or 6
     
  9. §outh§tar is feeling caustic Registered Senior Member

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    Go to hell.

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  10. Lucas Registered Senior Member

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    I would go if i knew how to go there. Do you know the address? You know: Hell ain't a bad place

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  11. Pete It's not rocket surgery Registered Senior Member

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    Hmmm...

    Sirius-B is smaller than Earth. Are white dwarfs not considered to be stars?
     
  12. 2inquisitive The Devil is in the details Registered Senior Member

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    I don't know why they wouldn't be, Pete. The Chandra Chronicles, at the Chandra
    x-ray observatories website, seems to imply even Venus, Jupiter, Mars and the moon
    are stars! HeHe. (Quote taken from diagram on left of article)


    "Sirius, Canis Major's Alpha star, is one of the brightest stars in night sky; only the Moon, Venus, Jupiter and Mars are brighter."
    http://chandra.harvard.edu/chronicle/0400/sirius_part2.html
     
  13. Lucas Registered Senior Member

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    I guess that what they have really found is the smallest main sequence star

    White dwarfs are stars, and are smaller than Jupiter, as Pete noticed
     
  14. Jolly Rodger Banned Banned

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    wouldn't that be the short guy out of austin powers
     
  15. Pete It's not rocket surgery Registered Senior Member

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    What does 'star' mean, in technical usage?
    Is it restricted to stellar objects undergoing fusion?
     
  16. superluminal I am MalcomR Valued Senior Member

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    From the article:

    I guess we get a little loosey-goosey with the word star. What about Neutron "star"?
     
  17. cosmictraveler Be kind to yourself always. Valued Senior Member

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    The colours of Orion
    © A. Vannini, G. Li Causi,
    A. Ricciardi and A. Garatti
    Stars come in lots of different colours.

    The colour depends on the temperature of the star:

    Hot stars are blue.
    Cooler stars are red.
    Hot stars can be as hot as 30,000 °C or more, but the coolest stars are only 1,000 °C.

    The Sun is quite a cool, yellow star. It is about 6,000 °C.

    The temperature of a star, and so its colour, depends on the amount of mass it has.

    Very massive stars, tens of times the mass of the Sun, are the hottest, and smaller stars with less than half the mass of the Sun, are the coolest.

    Although they are bigger, the hot, blue stars do not "live" as long as the smaller ones because they use up their nuclear fuel much more quickly


    http://www.schoolsobservatory.org.uk/astro/textb/stars/hotcold.htm
     
  18. gendanken Ruler of All the Lands Valued Senior Member

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    Lucas: I'd like very much to live in a planet with not only a Sun, but 5 or 6
    Ss: Go to hell.
    Lucas: I would go if i knew how to go there.
    Gendanken: masturbate



    I was there when we landed on the moon, by the way. And 145 extrasolar planets so far.........
     
    Last edited: Mar 9, 2005
  19. eburacum45 Valued Senior Member

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    Castor is a six sun system; the stars are arranged in pairs, two sets of bright stars and one set of red dwarfs. If you lived on a planet orbiting one of the bright pairs you might notice that the star in your sky was double, although it would be too bright to look at directly except at sunset; then you would see two stars next to each other close together in the sky.

    The other pair of bright stars would be much smaller, but they would be visible during the day. Occasionally the second pair would appear to come close in the sky to the pair around which this hypothetical planet is orbiting, and would be lost in the glare. At night the second pair would turn the sky deep blue and obscure most of the other stars.

    The third pair is relatively distant, and would only be visible as a pair of bright red stars at night.
     
  20. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    Smallest star ever detected
    All black holes are....
    Well, if you don't tke into consideration the Swartzshield radius.....
     
  21. Avatar smoking revolver Valued Senior Member

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    Not all, Seeker, some black holes are just interstellar gas exploding into a black hole without the star stage. It is believed that so are "born" most supermassive black holes, like the one at the centre of our galaxy.
     
  22. Lucas Registered Senior Member

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    How come? Black holes can form thru the process of supernova, that is a star exploding in a very brutal way. They can also form by the mergers of black holes, or could even exist mini black holes, left as a remnant after the Big bang, but they don't form by the process of "interstellar gas exploding into a black hole"
     
  23. Avatar smoking revolver Valued Senior Member

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    When there is a huge concentration of gas, why not? Say, two giant gas clouds come together. The mass becomes so big it explodes invards. (This is purely my speculation on how these supermassive black holes may be born in other ways) The black hole in the centre of our galaxy is as large as all our solar system.

    It also appears that when galaxies are first born it is when such gas cloud explodes invards, the centre becomes a supermassive black hole quazar and the rest of the not so concentrated gas (or most of it) becomes first stars in a galaxy.

    p.s. That is not my speculation/theory, heard it on a BBC Horizon serie "supermassive black holes"
    http://www.bbc.co.uk/science/horizon/2000/massivebholes.shtml
     

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