Sun's Sibling Found?

[Knight of Clear Skies]

Surprised there isn't a thread about this. A team from the University of Texas are claiming that they have identified a sibling to our Sun, born in the same nebula. They say it is the same age and has the same chemical composition (including proportion of some rare elements such as Yttrium). It's catalogued as HD 162826 and lies about 110 million light years away in Hercules. At mag 6.4 it's within easy reach of binoculars.

Pretty amazing if this is true. I've been wondering for a while if Gaia might be able to identify other stars from the same birth cluster as our Sun, in theory it should be possible with precise spectroscopy and if our stellar models are accurate enough. The Sun should have a few thousand siblings at least, but they must be pretty well scattered through the Milky Way by now.

Here's a finder chart:

I think I'll have a go at snapping it with my 50mm lens next time there is a clear sky.

It's in Stellarium as HIP 87382 if anyone is interested.

[Mav359]

Like it

Be interested in knowing if they have checked it for any exoplanets as well

[ChrisLX200]

Like it

Be interested in knowing if they have checked it for any exoplanets as well

Article says there are no 'hot Jupiters' in the system but still leaves the possibility of terrestrial-sized planets (and others further out I guess).

ChrisH

[animaal]

It's 110 light years from us. That's not very far to have travelled, given that the sun is 4.6 billion years old.

I never knew that stars formed in the same area would have similar chemical compositions. Interesting.

[Peter Drew]

That's one million times nearer, I thought that mag 6.4 for a star at 110 million light years distance was a bit bright. 

[johnrt]

I never knew that stars formed in the same area would have similar chemical compositions. Interesting.

I think it's a reasonable guess, if the stars accreted from the same dust and gas clouds, their chemical composition must be similar, or identicle.

[animaal]

Yes, it sounds reasonable. It also means that the dust and gas was non-uniform in the cloud. Maybe the heavier elements revolve closer to the centre of the cloud, similar to how denser planets formed closer to our sun.

[crashtestdummy]

Was thinking the same as 110m light years would put it outside our galaxy.would closer stars light alpha and proxima centurai likely be formed in the sane nebula as ours despite their differing sizes, compositions and ages?

[Knight of Clear Skies]

Sorry, no idea how the word 'million' appeared somewhere between my brain and the keyboard. That should of course read '110 light years'.

[symesie04]

Yes interesting how you have managed to unintentionally add a million to the total. Just out of interest could you lend me a pound?

[Cath]

Fascinating to think that their may well be beings out there with very similar ratios of raw materials available for them to evolve from and have available for building from, and to be our 'relatives' as it were.

Our Sun (our life support) has a family out there

[Knight of Clear Skies]

Yes interesting how you have managed to unintentionally add a million to the total. Just out of interest could you lend me a pound?

Sure, but don't be disappointed if a few penny shavings turn up in the post.

It's 110 light years from us. That's not very far to have travelled, given that the sun is 4.6 billion years old.

I'm guessing a bit, but it may have spent much of its life much far from us and just happens to be passing rather than orbiting in loose formation with our Sun. Its proper motion is listed here, I think that's milliseconds of arc per year. If I'm understanding it correctly it's moving at a fair lick relative to us.

Since the Sun (and its siblings) formed 4.5 billion years ago we've been around the Milky Way about 18 times or so. In that time the individual stars which made up our birth cluster will have been jiggled all over the place, tugged by the gravity of passing molecular clouds and stars. I'd be unsurprised if some of them are on the other side of the galaxy by now. However, by chance some of our siblings are likely to be in the vicinity at any one time.

Does the Sun have many siblings or only a few, did it form in a large or small nebula? HD 162826 (if confirmed) could be a hint of the first scenario, the more there are the better the chances of finding one in the relatively small volume we can look. Gaia, designed to catalogue 1 billion stars or roughly 1% of the Milky Way's population, may be able to provide an answer to this question.

[jabeoo1]

I am glad there is a thread on this.  I just read the article via an email form Sky & Telescope (Well worth signing free to by the way).  Fascinating stuff, astronomy is amazing.

[ollypenrice]

Yes, this does indeed need to be a far bigger thread. Thanks for the heads up. The research potential in years to come, I'd have thought, should be mind blowing.

Olly

[Knight of Clear Skies]

Took a quick snap of HD 162826 a couple days ago. It's a rubbish image (50mm lens, f1.8, 5 seconds) as not only was there a full Moon to contend with, but I took it from inside a town and forgot to turn off auto-ISO. Hence the very sparse starfield, the camera decided on a measly ISO 160. Was pleased to get it nonetheless.

Hopefully someone can get out there and take a proper image of it, that group of 3 makes a pleasing asterism.

[Paranoidsam]

It's 110 light years from us. That's not very far to have travelled, given that the sun is 4.6 billion years old.

I never knew that stars formed in the same area would have similar chemical compositions. Interesting.

Well, it almost goes without saying really... Since both stars would have formed from the same material.