What is the nearest single, type G star to the sun?
I ask because I would expect that non-binary systems of type G stars are the most likely to have inhabited/inhabitable planets. If we are going to look, I would start there, by checking for radio transmissions, or whatever.
So, assuming that most single, type-G stars have the best chances of life-bearing planets, what is the closest one to us?
Regards,
Shodan
Here is an interesting 3D map of the stars withing 50 LY of Earth. The yellow ones will be G-type stars similar to our own Sun. From a quick overview, it appears the G star, n(nu)Bootes is the closest one after Alpha Centuari.
Thanks!
Regards,
Shodan
I don’t see Nu Bootis on that list.
The closest unary G star is Tau Ceti. Type F and K stars can also be suitable for life, for example Epsilon Eridani, (a K2) which is closer to us and has planets, but is a young system still in its formative stges. The closest candidate for existing extrasolar life at this point seems to be Tau Ceti.
Ack. Sorry, that’s an eta, not a nu.
Actually, tau Ceti, at 3.67 parsecs, is the closest single G-type star to the Sun. Another star considered a good prospect for extraterrestrial life is epsilon Eridani, which is a little close (3.28 pc), but it’s a K type, which makes it somewhat cooler and dimmer than our Sun or tau Ceti.
As a side note, in some versions of the Star Trek canon, epsilon Eridani is said to be the location of the Vulcan homeworld. Not that that’s relevant, of course.
Does K type mean it is older than the sun? Or less massive? I can’t remember the relationship between type and age (sorry, Dr. Bless).
If a star has gone thru the red giant phase, I expect any life in its system would be gone.
3.67 parsecs is, what, eleven light years? So if we first started emitting in the radio bands during the last century, that is plenty of time for them to notice. Assuming they use radio astronomy.
Off to Google info on tau Ceti. Thanks to all.
Regards,
Shodan
The class letter is the mass of the star. More massive ones tend to be younger because they burn out so much faster. I’ve never read exactly why the letter order is what it is, but to remember, I use one of my favorite mnemonics:
Oh Be A Fine Girl, Kiss Me Right Now, Sweetie
O is the most massive. F. G, or K can all be considered close enough to support an earth-type planet, if you squint enough. tau Ceti is less massive, but close.
DD
The closest sun-like star SETI-target with confirmed planets, as of 06-10-04 is 55 Canceri A [(a.k.a Rho(1) Cancri] Part of a binary system, one star (A) is sol-like, with possibly two bigger than Jupiter planets inside of Earth’s orbit. Sounds funky I know but:
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…dynamical calculations by Greg Laughlin (University of California at Santa Cruz) suggest that “an additional planet of terrestrial-mass” could have a stable orbit around the Earth-Sun distance of one AU (Marcy et al, forthcoming 2002, in pdf). The orbit of an Earth-like planet (with liquid water) around Star A may be centered as close as 0.76 AU – between the orbital distances of Venus and Earth in the Solar System – with an orbital period of 260 days, close to an Earth year.
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No, the letters denote the spectral class, which relates to the temperature of the star. See [here]](http://www.astro.uiuc.edu/~kaler/sow/class.html) for some additional information.
Not only is looking at nearby sun-type stars the most logical thing to do, it was (literally) the first thing that SETi scientists tried. From here:
[quote]
In 1960, radioastronomer Frank D. Drake, then at the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia, carried out humanity’s first attempt to detect interstellar radio transmissions. … The stars chosen by Drake for the first SETI search were Tau Ceti in the Constellation Cetus (the Whale) and Epsilon Eridani in the Constellation Eridanus (the River), some eleven light years (66 trillion miles) away. Both stars are about the same age as our sun.
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Ah, dagnabit. That’ll learn me to post without previewing.