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Old 10-02-2014, 12:51 PM
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mithrandir (Andrew)
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Oldest Known Star found by ANU Team

Quite a few links floating around for this. http://www.neogaf.com/forum/showthread.php?t=766283 seems a reasonable summary, unless you have access to the journal Nature.

WISE J031300.36-670839.3
RAJ2000 03 13 00.366
DEJ2000 -67 08 39.38
W1mag 12.534 mag WISE/W1 magnitude Red values correspond to upper limits (S/N<2) (3.35um) (phot.mag;em.IR.3-4um)

With that magnitude quite a few IISers should be able to spot it.
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Old 10-02-2014, 02:30 PM
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Nice find Andrew! I'm not sure what WISE red magnitudes are but the NOMAD1 catalogue gives B=15.290, V=14.880, R=14.100 (NOMAD1 0228-0034083, USNO-B1 0228-0034152, UCAC2 2359678, sourced through Vizier).

Cheers -
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Old 10-02-2014, 08:06 PM
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glenc (Glen)
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The Guide star atlas gives the oldest star's mag = 14.87.
The star is 45' SW of NGC 1313.
The arrow in the lower right of the attached image points to the star.

See also
http://www.iol.co.za/scitech/science...rint-1.1644462
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Old 11-02-2014, 03:10 AM
RefractorPhill (Philip)
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In which Southern constellation is that precisely ?

http://ruimtelogs.scilogs.be/index.php?blogId=14
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Old 11-02-2014, 04:08 AM
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It is in Hydrus. (Hyi)
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Old 11-02-2014, 11:37 AM
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pdalek (Patrick)
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See
http://arxiv.org/abs/1402.1517
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Old 12-02-2014, 04:32 PM
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There is a nice LMC SMC picture with this oldest star story.
http://newswatch.nationalgeographic....-the-universe/
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Old 14-02-2014, 02:20 PM
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See also
http://www.nature.com/nature/journal...ture12990.html
http://www.nytimes.com/2014/02/11/sc...s.html?hp&_r=1
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Old 14-02-2014, 02:30 PM
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astroron (Ron)
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Gary, I still reckon there is an anomaly somewhere and it will bring this star back to the pack.
Star formation is not yet an exact science in my view.
About 15 years ago they were saying Globular Clusters were older than the Universe, they had to change their minds about that.
Stars didn't collide, they had to change their minds about that also.
Stars shouldn't be more massive than 100 solar masses they've changed their minds about that also.
They now talk of stars of upto 300 solar masses, which shouldn't be possible under current Star physics.
Cheers
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Old 14-02-2014, 03:39 PM
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Quote:
Originally Posted by astroron View Post
Gary, I still reckon there is an anomaly somewhere and it will bring this star back to the pack.
The details of the interpretation may change but there is absolutely no doubt that this is a highly unusual star, possibly unique in the Galaxy. Just looking at the spectrum (you can see it here: https://twitter.com/annafrebel/statu...71786930130945) shows that this is no ordinary M-dwarf, such spectra are usually full of absorption lines but this has hardly any. The non-detection of iron lines means that the iron abundance must be at least 30 times lower than the previously most iron poor star known and over 12 million times lower than the iron abundance in the Sun!

Granted there are uncertainties about the exact age and ancestry of this star but that's exactly what makes it so interesting. If we can nail down the details this ancient star will tell us a lot about the generation of stars that preceded it, i.e. the very first stars in the universe.
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Old 14-02-2014, 03:54 PM
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Quote:
Originally Posted by Hotdog View Post
The details of the interpretation may change but there is absolutely no doubt that this is a highly unusual star, possibly unique in the Galaxy. Just looking at the spectrum (you can see it here: https://twitter.com/annafrebel/statu...71786930130945) shows that this is no ordinary M-dwarf, such spectra are usually full of absorption lines but this has hardly any. The non-detection of iron lines means that the iron abundance must be at least 30 times lower than the previously most iron poor star known and over 12 million times lower than the iron abundance in the Sun!

Granted there are uncertainties about the exact age and ancestry of this star but that's exactly what makes it so interesting. If we can nail down the details this ancient star will tell us a lot about the generation of stars that preceded it, i.e. the very first stars in the universe.
Basicly what I was trying to say.
I still find it hard to take in that you can have a star that is between 2-3 billion years older than the galaxy, and survived Supernova and star forming going on in the Early formation of the galaxy.
That it is only 6000 light years from the Sun is even more amazing.
I know that the galaxy is not as active in Star formation as it used too be, which makes it more amazing how long it has stayed around.
I understand that the first stars were massive and had little or no metals and did not last too long, so how did this star survive
Cheers
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Old 14-02-2014, 05:14 PM
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mithrandir (Andrew)
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Quote:
Originally Posted by astroron View Post
I understand that the first stars were massive and had little or no metals and did not last too long, so how did this star survive
Ron, this isn't an early massive star (Population III). Its a Population II star, but a very early one. The hypothesis is that the Pop III supernova whose remnants it formed from didn't release much Fe with most of the heavy elements falling into the black hole. M dwarf stars last for tens of billions if not hundreds of billions of years, even trillions, so it still being around is not surprising.
The galaxy is an accumulation of smaller galaxies which date back to about the Big Bang, so it can easily contain stars over 10 billion years old.
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Old 15-02-2014, 10:05 PM
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Read This,it agrees whith what I am trying to say exactly.
http://theconversation.com/the-oldes...aybe-not-23113
Cheers
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Old 15-02-2014, 10:16 PM
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astroron (Ron)
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BTW I am not unaware of the different classes of star formation,and that is why I am sceptical of these claims.
This quote from Hotdog (Anthony) in his reply also says what I am saying.

Quote)
"The details of the interpretation may change"
Yes it is an unusual star,but as instrumentation and telescopes get better etc, we will find many more "unusual" stars. and IMHO will have to revise some of the bounderies that we take for granted.
Cheers
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