great list, thanks for the link

I wonder how long it will be before we see those names on SCI-FI.

Personally, I have a lot of problems with the stars on the list, though frankly I won't lose sleep over it. i just hope she gets a chance to actually *search* those stars.

But, out of curiosity, what are some of the most "friendly" stars, in terms of their characteristics? My top 5 list would be:

Beta Canum Venaticorum
61 Virginis
Beta Comae Berenices
18 Scorpii
37 Geminorum

__________________
"There is a technical, literary term for those who mistake the opinions and beliefs of characters in a novel for those of the author. The term is 'idiot'."
-- Larry Niven

Indeed, the most promising stars are those which doesn't have known planets but still are metal rich. They may have Jupiters in distant, circular orbits. We just don't have enough data or sensitivity to detect them yet.

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

You can add HD 98618 in the Big Dipper to the list. It's the second-best solar twin ever found (after 18 Scorpii). Details here.

[quote=Harvestar]sigh... This is, I'm afraid, the problem with current modes of press releases. I'm sure Maggie meant spectral class, but, unfortunately, "one doesn't put that into a press release." I've had similar problems trying to explain my own research in a press release (which did make it to Universe Today).

Should one use "spectral class", certainly, but how many "common" people know what those words mean. (y'all excepted, of course )?

The common "dumbing down" of press releases is a difficult issue. How much does one assume about the public and who is reading it? Do you assume they know the word "luminosity"?


As a high school teacher in a new school, I pointed out the moon, visible in daylight, and as a joke, commented..."Look, the moon!....and I can see little footprints where they walked on it." The students ,I thought, would find it ludicrous that I would be able to see footprints from Earth....instead...78 of 81 thought I was insane for suggesting that anybody ever walked there (Spring,1983)...so you can't assume "the public" will know very much.

__________________
A third rate theory forbids
A second rate theory explains after the fact
A first rate theory predicts...A. Lomonosov

Alas, without a binary star model for habitable-zone planets, Sirius is nowhere on anyone's list. How come?

It's an A star - too short lived (and possibly too much UV within the CZ).

__________________
My message board, now more fun than ever - Text effects - Sky photos - Element spectra
Remember I before E except after C, or be seized by your weird neighbors who have had too much caffeine.

And its companion has already died -- Sirius was not a nice place to live when Sirius B was a red giant.

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

My condolences to the Dogon theorists.

Nothing kills theories like that more than time and a better understanding of stellar evolution. When the whole Dogon thing started, did we even have a clue how old Sirius was? IIRC, it's now known to be about 250 million years old.

...John...

__________________
"There is a technical, literary term for those who mistake the opinions and beliefs of characters in a novel for those of the author. The term is 'idiot'."
-- Larry Niven

It's interesting that the Dogons themselves seem to be unaware of the myth...

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

Hi there--OK, wait, is it a good thing to have your work talked about on "Bad" Astronomy? Yikes. But I've enjoyed reading some of these posts.

I've just had a quick glance over some of the comments, and I think people appreciate some of the unknowns associated with doing this work. For example, 51 Peg. A giant planet migrating through the hab zone and sweeping up any "junk" (as Doug Lin would say) orbiting there is potentially bad news for habitable terrestrial planets. However, given that we don't know much about planet formation, and that planet formation theory has been turned on it's head in the past by new discoveries (e.g. 51 Peg), I opted not to rule out this star based on that consideration alone. The habitable zone is dynamically stable given the presence of all (1) known giant planets in that system.

Some people have mentioned other stars as well, and this is where I point out that our real SETI target list actually has thousands of stars that all passed the criteria of:

-age > 3 Gyr
-non-variable/non-flaring
-companions, including GPs, don't interfere with HZ
-at least half-solar metallicity
-kinematics indicating thin disk population, non-spiral arm crossers
-mass allowing for at least a 3 Gyr lifetime

and a few other things that I'm forgetting right now. Stars passing with flying colors include 37 Gem, 18 Sco, beta CVn, 61 Vir, and of course, HD 98618, among other good friends. These are all top candidates that will get observed ASAP. Stars NOT passing with flying colors include the alpha Cen system, whose orbits probably preclude the delivery of water to inner planets, even though alpha Cen B is probably the easiest place in the Universe to _detect_ Earth-like planets in the habitable zone if they are there. Nevertheless SETI will also observe alpha Cen because we promised to search all of the nearest 100 stars regardless of habitability concerns.

As you can guess, the press does not really want to hear about thousands of fantastic stars, and for an overview showing the characteristics we were looking for, I presented these five. As an aside, I found that in-print articles were the hardest to interview for, because of mis-quotes and oversimplification to the point of being wrong--although in this case I was actually quite satisfied with most articles. I mean, hey, we've got the press talking about things like stellar metallicity!!!! Radio was easier, if more nerve-wracking, because I just said what I meant.

Thanks a lot for your comments.

Thanks Maggie for taking the time to comment on our discussion!

...and welcome to the board!!

Okay, see? Now I'm nervous that my earlier comments sounded way too harsh! **wry chuckle** Considering how much I admire your work and the remarkable effort put forth thus far, let me do some serious brown-nosing and say that I'm glad that you've been able to join the forum and put forth some comments of your own. Alright, onward....

That certainly opens up some possibilities, doesn't it! I've always wondered why, even if a planet *does* migrate inward, there wouldn't be enough material left behind to reform a second early generation of planets. Planet formation is, as I understand it, even faster of an event than what we believed a handful of years ago, and certainly a Jovian moving inward wouldn't remove *all* of the available planet building material.

As far as metallicity, is that the standard accepted value for allowing large, terrestrial planets, or is there a hefty margine provided here for safety's sake? I once emailed Seth Shostak on the question, and was lucky enough to get a response back, where he indicated that stars with as little as 0.3 of Sol could be suitable. However, this was a few years ago now, and theories and hard data have almost certainly changed....

Oh, man, I was almost bang on, eh? Nice! I don't suppose you could name the other "good friends". I have this thing about very friendly, Solar analogue stars....

Yeah, despite my own high interest in Alpha Centauri, which borders on an unhealthy obsession, I've always thought that the system would be fairly poor odds. But my thoughts were always surrounding the possibility that, while stable orbits exist now, were the A and B components always orbiting as they currently are, or was there some early formation issues where their orbits could have been a bit different, and only eventually evolved into the current configuration? At best, I figured there's be some terrestrial worlds about each star, but that these would be lifeless pieces of rock in eccentric orbits.

Thank you for taking the time to read them, and to comment on them! It's wonderful to have someone "in the thick of it" come aboard and comment!

...John...

__________________
"There is a technical, literary term for those who mistake the opinions and beliefs of characters in a novel for those of the author. The term is 'idiot'."
-- Larry Niven