SkyMapper turns up oldest star ever found It's a one-in-60-million search: a group of astronomers has turned up a “second-generation” star, the oldest yet discovered. The star, while given an age of 13.6-plus billion years (more on this later), is quite nearby at just 6,000 light years distant, and is in the Milky Way. What's special about SMSS (SkyMapper Southern …
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Large stars burn faster, much faster. Very large stars can last as little as a couple of million years. So as a early second generation star it will have formed from the debris of large first generation stars. This star won't be very big. The previous candidate for oldest star is 0.8 solar masses, according to wikipedia.
Yes its a weird one this, I had to go and check the numbers - I was going to suggest that "time-of-flight" was where the other billions of years had gone, that's the normal answer to the very-old-stars-observed question.
Not in this case however, this star is only a few thousand light-years away, right next door on these billion light-year scales.
I wonder if it must be from an unusually sparse region of the universe that has not seen much if any star formation. Perhaps only relatively recently (in the last billion years) did this one have the mass to collapse into a star, accretion can be very slow if the primordial gas is thin enough. Is it a dinosaur born late?
The paper covers some more interesting theories, suggesting that all its neighbours must have self-immolated into black holes carrying all their iron etc with them - though normally even in the "full collapse" scenario a load of metals get spewed into space. The "gentle supernova" they propose sounds unlikely, even if it does then solve the Lithium problem.
Assuming it actually went supernova and didn't just collapse in on itself.
If the big bang theory is correct, the matter would be relatively densely located versus what we observe today, if due to this density and relatively low mass of the elements.
The stars could get big, really big, possibly some big enough to for gravity overcome the energy from fusion and just collapse in on themselves.
No Bang just blackhole.
The "wimpyness" of early supernovae is of course relative. They still would make simultaneously setting off the entire nuclear arsenal on earth look like an ant sneezing. Having just observed a "bog standard" Type 1a supernova shine nearly as brightly as an entire galaxy (SN2014J in M82), I am always staggered by the sheer scale and violence of these events.
Icon, because that's a seriously wimpy explosion
I liked the comparison in this xkcd whatif. A supernova observed from the distance of the sun (1 AU) would be brighter than a nuclear bomb detonating pressed against your eyeball. I mean... assuming your could survive either of those things to notice.
"These show that the star has very little iron – at a maximum of 10-7.1 the concentration in our Sun, it's the most iron-poor star ever characterised."
Does that mean that the "old" star has a concentration less than1e-7.1 _times_ the concentration in our sun?
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