28 Aug '13 15:21>
http://phys.org/news/2013-08-oldest-solar-twin-vlt-clues.html
Originally posted by humyI think they mean it's got the same classification G2V, which constrains the mass fairly tightly. It's still in the main sequence, so it's properties won't have changed that much, although it's power output will be higher than earlier in it's lifetime. From memory, the losses from solar wind for dwarf stars aren't that intense until they stop being dwarfs. According to the Wikipedia page on Solar Wind the sun's so far lost about 0.01% of its mass, so it's unlikely this other star will be much different.
Strangle, the link doesn't explain exactly in what way this star is very much “like” Sol.
Anyone:
Do they simply mean (by “like” ) it has almost exactly the same mass as Sol? If so, then their assumption that it could show us what Sol would be like 4 billions years time is deeply flawed because Sol would loose a large proportion of that mass by the ...[text shortened]... rs which may not necessarily be totally accurate or reliable? -this would be my main concern.
Originally posted by DeepThought
I think they mean it's got the same classification G2V, which constrains the mass fairly tightly. It's still in the main sequence, so it's properties won't have changed that much, although it's power output will be higher than earlier in it's lifetime. From memory, the losses from solar wind for dwarf stars aren't that intense until they ...[text shortened]... means that the amount of lithium in the star gives you information about how old it is.
According to the Wikipedia page on Solar Wind the sun's so far lost about 0.01% of its mass
Originally posted by DeepThoughtWow, that means for people living there, lithium ion batteries are going to be WAY more expensive than here on Earth! So lets form a trade union and go there and sell them lithium!
I think they mean it's got the same classification G2V, which constrains the mass fairly tightly. It's still in the main sequence, so it's properties won't have changed that much, although it's power output will be higher than earlier in it's lifetime. From memory, the losses from solar wind for dwarf stars aren't that intense until they ...[text shortened]... means that the amount of lithium in the star gives you information about how old it is.
Originally posted by humyI had a look at the paper (they get the wrong end of the stick every now and again but phy.org get credit off me for making the basic research easy to find) which is here: http://www.eso.org/public/archives/releases/sciencepapers/eso1337/eso1337a.pdf and they're basis for the claim about composition seems to be based on previous work. I've only read the introduction and I'm off field, so... Although their primary interest seems to have been lithium, if I've read it right they measured the other metals as well. They'll be looking at spectroscopic line brightness (not in the intro), but further than that this is beyond my ken. They're helped a lot by the proximity of this star - for example at a mere 250 light years its distance will be known from parallax measurements which are quite accurate.According to the Wikipedia page on Solar Wind the sun's so far lost about 0.01% of its mass
Yes, I just checked this and you are right. My memory completely failed me here because I thought I remembered reading somewhere that it lost a lot more than that!
Must have somehow got that mixed up with the substantial mass it would loose when i ...[text shortened]... elements compared to the heavier chemical elements and others having a much smaller proportion.
Originally posted by sonhouseThe amount of lithium in the Earth is not related to the amount of lithium in the Sun. For a terrestrial planet around that star the percentage composition will depend on the collapsing nebula's composition - not the amount of lithium in the star, since that all gets burnt in the proto-star stage.
Wow, that means for people living there, lithium ion batteries are going to be WAY more expensive than here on Earth! So lets form a trade union and go there and sell them lithium!
Originally posted by DeepThoughtBust my party will you🙂
The amount of lithium in the Earth is not related to the amount of lithium in the Sun. For a terrestrial planet around that star the percentage composition will depend on the collapsing nebula's composition - not the amount of lithium in the star, since that all gets burnt in the proto-star stage.
Besides with a round trip of at least 500 years you won't get much investor interest.
Originally posted by sonhouseIt is my opinion that by the time we have the technology to do that, robotics will have advanced enough to do the job and we wouldn't want to send people at all, unless we are establishing a new colony for the sake of procreation.
A generation ship going 0.1c would take 2000 years one way with no appreciable relativistic effects. I suppose a trip like that could be planned where everyone is cryogenically frozen or you have frozen embryo's decanted say 25 years just before arrival and robots bring up the kids with lots of recordings of images and voices from Earth. Lots of ethical concerns there!