Astronomer Margaret Turnbull has determined a list of ten stars around which efforts should be concentrated to find Earth-like planets. There are five stars each for the new SETI radio telescope search plan, and then the Terrestrical Planet Finder, which is currently on hold. Where should you be looking? How about here, from an exerpt:
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SETI stars
Turnbull’s top habstar candidates for the Allen Telescope Survey:
Beta Canum Venaticorum: a Sun-like star about 26 light years away in the constellation Canes Venatici. This was Turnbull’s top choice for SETI. HD 10307: a near replica of the Sun but with a companion star. Located about 42 light-years away, this star has almost the same mass, temperature and metal-content as the Sun. HD 211415: has about half the metal content of the Sun and is a little cooler; just slightly farther away than HD 10307. 18 Sco: a near-identical twin of the Sun, located in the constellation Scorpio. 51 Pegasus: The first planet beyond our solar system was detected around this star in 1995. Although that planet was a gas giant, Turnbull thinks 51 Pegasus could harbor rocky planets as well.
All of these stars have already been surveyed by SETI’s Project Phoenix in the past without success, but the Allen Telescope Array will have up to five times Project Phoenix’s frequency range, making it more likely that a habitable planet around these stars will be detected if one exists.
TPF stars
For the TPF mission, Turnbull chose the following five stars: Epsilon Indi A: Turnbull’s top TPF mission choice; this star is only about one-tenth as bright as the Sun and about 11.8 light-years away in the constellation Indus. Epsilon Eridani: This star is a bit smaller and cooler than our Sun; it is located about 10.5 light-years away in the constellation Eridanus. Omicron2 Eridani: A yellow-orange star about 16 light-years away that is roughly the same age as our Sun. Alpha Centauri B: This triple star system is located just 4.35 light-years away and one of the Sun’s closest stellar neighbors. Tau Ceti: This star is a G-class star and is in the same brightness category as the Sun. Despite being relatively metal-poor, it is long-lived enough for complex life forms to evolve.
posted
I'm not talking about the difference between name and catalogue designation. I'm talking about why one star would be listed as both '40 Eridani' and 'Omicron2 Eridani'. Omicron is only the fifteenth letter in the Greek alphabet.
And just to pick an even finer nit, 'Alpha Centauri B' is not a ternary system. 'Alpha Centauri' is. I'm curious as to why 'B' was the one she indicated. 'A' is a G2 or G3 yellow sun very much like ours, but 'B' is orange (about a K0, if I remember correctly). And just to cap it off, Alpha Centauri C -- or 'Proxima Centauri' -- is the nearest actual sun to ours at only 4.33LY. At least, that is, until it swings back around behind A and B in its orbit.
--Jonah (Geek? Moi?)
-------------------- "That's what I like about these high school girls, I keep getting older, they stay the same age."
--David "Woody" Wooderson, Dazed and Confused
Registered: Feb 2001
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posted
Frustratingly (although perhaps not unexpectedly), over the centuries there have been several stellar catalogues which use differing criterion for their naming system of choice. And so depending on binary, trinary, variability, etc. one star may have several different designations. "Keid" would be the Arabic name dating from the middle ages (which means egg shells, btw), "Omicron2 Eridani" would be the Greek Letter Name assigned by that grand kraut Johannes Bayer (based on the constellation and apparent brightness) and "40 Eridani" would be the Flamsteed number which is based on the star's position (right ascension & declination) within the constellation boundary. Which isn't even getting into the more recent (and comprehensive) star catalogues the cross referencing of which is a science of itself. The HD numbers mentioned in the original post refer to the Henry Draper memorial catalogue.
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posted
Isn't this mess what the new general catalouge was set up to sort out? Or is that just for nebulae and stuff?
-------------------- I have plenty of experience in biology. I bought a Tamagotchi in 1998... And... it's still alive.
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posted
So it's more everybody deciding that their system is better than anybody elses and publishing it. Fecking astronomers.
-------------------- I have plenty of experience in biology. I bought a Tamagotchi in 1998... And... it's still alive.
Registered: Apr 2005
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posted
I've always been happy with the old Arabic names (where available), supplemented by the latin names (mostly S. hemisphere), and all referred to by their magnitude within the constellation.
Although it will be tough to "unlearn" the odd well-known name from other lists, like Wolf 359. *heh*
All but a couple of the twenty-five brightest stars that we can see from the Northern Hemisphere have Arabic names. But the twenty-five closest are boring as can be, with catalogue listings (at least five catalogues represented) and a depressing amount of numbers.
Similarly, the first non-stellar catalogue I learned was the Messier catalogue, and I still prefer that to the NGC catalogue. Sorry, but "M-31" is permanently etched on the skin of my brain.
--Jonah
-------------------- "That's what I like about these high school girls, I keep getting older, they stay the same age."
--David "Woody" Wooderson, Dazed and Confused
Registered: Feb 2001
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