Nearby star is almost as old as the Universe

http://en.wikipedia.org/wiki/Metallicity

Stars below 0.1 solar masses are estimated to keep burning for trillions of year.

it's not surprising for small stars to live a long time (they burn quite slowly). what's surprising is that we don't see any older than about 14 billion years old.

so that suggests that the universe is only that old.

and really, to astronomers, that's not surprising either, since the universe is known to be that old from other measurements.

what's actually surprising is that this star matches the universe's age so closely when it contains some elements other than hydrogen or helium. since that implies that it wasn't one of the first stars made (which would be pure hydrogen and helium), but a star made from remnants of other stars. so it is at least "second generation". so there must have been some stars of short lifetime before it. and it's actually tricky to fit that in, given how we think stars are created and how the universe evolved (the real problem is that the hydrogen starts out fairly evenly spread out and needs time to clump, under gravitation, to form the first stars - the density fluctuations that describe this are constrained by observations of the microwave background, which is quite smooth).

[some more background to make this consistent: the universe "started" as hydrogen; large stars, which live a short time, can make other elements than helium from hydrogen; small stars, which live a long time, make only helium from hydrogen.]

So with all the mixing and matching that has gone on over time, we've picked up many stars from many different stages of galactic evolution. Its not unusual at all to find such an old star.

That would be a misconception on your part. Excepting galaxies created due to collisions between other galaxies, all galaxies are believed to have been formed around the same time, and then got separated by the expansion of the universe. So yes, we are one of the first galaxies..just like every other galaxy. Thus we had stars created at all points of time, and some have survived.

That said, there is a more interesting question underlying "why its close to us" that deserves comment. It turns out that the Sun has a tendency to oscillate up and down through the galactic halo. This is good for the Earth, because it limits our time spent in neighborhoods where there is a lot of other stuff we can run into. However early star formation took place in the galactic plane, so most old stars are very near the galactic plane, and therefore the Sun is usually not close to them.

I believe that the period of the oscillation is somewhere in the neighborhood of 64 million years, so we punch through the plane about every 32 million years or so. We last passed through an estimated 3 million years ago, and are currently about a hundred light years away from the plane, so we are still near objects in the plane, including old stars like this one. But in another 10 million years, we shouldn't be!

That's not a very well-defined statement, since there is no absolute simultaneity between here and a distant area of the Universe.

Anything that we can measure shows the star still there, even if stellar evolution allows us to accurately predict that it wouldn't be if we could travel there faster than light.

Its 190 light years away. That's close.

That means that its light has only taken a bit less than 200 years to reach us, compared to the millions and billions of years we see when looking at distant galaxies.

The star has been around for 13 some odd billion years. Its very unlikely that it finally exploded in the last 190 years.

As for comments about universal expansion, no simultaneous events happening, yada yada, none of that applies nor has anything to do with an old-ass star that's literally on our doorstep.

I'm not going to get into a physics debate right now, but suffice it to say that if you were here and I was there (somewhere around the star), the light from both stars would be 190 years old to each of us. You and I would comfortably be existing in the universe at the same moment as long as we weren't travelling at relativistic speeds.

For a closer-to-home example, imagine that I am sitting at my desk in my office. (I am.) And you are currently reading this in the car or on MUNI moving at 30-60 mph. Are you going to say that I, or you, don't currently exist at the same moment on the same planet or even the same city (San Francisco) because you're going slightly faster than I am?

Extracted from / More information / Images : http://server7.sky-map.org/starview?object_type=1&object...