To continue this completely off-topic discussion....
I just looked it up, there are 6,300 or so F and G type stars in the solar
neighborhood for every 10^6 pc^3, so it works out there should be 6,100 or so
in a sphere of 200 ly centered on the earth. For stars that are close to the
sun in surface temperature and total luminosity, you might want to cut that
number down by a factor of 5 or so. I only
included main-sequence stars, no Giants. I got all this from a great
book that recently went out of print called Galactic Astronomy by Milhalas and
Binney. Mark K should at least have a copy available at the ST library.
cheers brad
> @:) I understand there are around 70,000 stars within 200 LY of the
Yes, our sun is a G2 V, Main Sequence (dwarf) star.
> stars within 200 LY? Or other types that might likely be capable of
<snicker> I don't know of any lists that have been divided up into spectral
types by distance. However, if you're feeling adventurous, find yourself a
copy of the "Sky Catalogue 2000.0, Vol 1, Stars to Magnitude 8.0". Within you
will find over 600 pages of information on the stars that are 8th magnitude
or brighter, including spectral type, approximate and/or estimated
distance, location in the sky, etc.
Note: there are, on average, 75 stars listed per page. Simple math exercise
for the reader how many stars are listed in that book. Extrapolate for the
fainter ones (see Note #3).
Note #2: at a distance of a mere 150 ly our sun would drop below 8th magnitude
and thus not be listed in this catalog.
Note #3: there are a lot of stars that are much, much closer that will not
appear in this catalogue (eg, Barnard's Star, for example, is magnitude 9.5
but only 6 ly away). Although the majority of these stars would fall outside
of your desired request range.
Note #4: there are astronomy books out there (I don't have mine handy at the
moment) which do list the '20 Brightest Stars' (and their distances),
as well as the '20 Closest Stars' (and their distances/apparent
brightness).
Mk
> I wrote:
> I don't know of any lists that have been divided up into spectral types
BTW, the distances used in the catalog are in *parsecs*, not lightyears.
You'll have to convert... ;-)
(3.26ly = 1pc for those who don't know)
Mk
> To continue this completely off-topic discussion....
Yeah, there's a copy somewhere up in the library. I have a personal copy, too,
but it's at home, buried in a ton of other books. Haven't looked at
that in...a while :-/ But I'll be digging it up soon enough... At
the moment, down here in Ops, the only thing I have available are the Sky
Catalogue 2000.0. and the Burnham's Celestial Handbook series.
Mk
Excerpts from FT: 8-Sep-97 Stars (was: RE: [OFFICIAL] .. by EPICS: S. W.
Tours@stsci
> >stars within 200 LY? Or other types that might likely be capable of
[snip]
Alternately, you can check out the Near Star List in 2300 AD, which lists all
stars within 50 ly of Sol, and (if you buy the Kafer sourcebook) 25 ly (I
think) of the Kafer homeworld. (There's a good bit of overlap in there,
though.) All in all there are roughly 750 stars listed there... it's based off
the second edition of the Gliese Star Catalog, IIRC, and some of the data
changed in the third edition, but what the heck.
Also, 2300 AD has a nice system for placing planets... they do some fiddling
with the temperature of the star to determine a 'life zone' where temperatures
on a planet's surface will be vaguely Earthlike.
Later,
> Bradford Holden writes:
@:) To continue this completely off-topic discussion....
It's better than some recent discussions.
@:) I just looked it up, there are 6,300 or so F and G type stars in @:) the
solar neighborhood for every 10^6 pc^3, so it works out there @:) should be
6,100 or so in a sphere of 200 ly centered on the earth. @:) For stars that
are close to the sun in surface temperature and @:) total luminosity, you
might want to cut that number down by a @:) factor of 5 or so.
Using an on-line reference of nearby stars, the same one mentioned
by Tre, I think, I found 670 G, low-numbered F, or high-numbered K
stars within 25 parsecs (81.5 ly). That sounds like about 1158 within 100 ly.
Choose your own likelihood of planets but it sounds like a relatively large
number of systems. The reference is:
Cat.of Nearby Stars,3rd Ed.(prelim.) (CNS3) Gliese,Jahreiss,1991,
and I found it at:
http://adac.mtk.nao.ac.jp/index.html.
Thanks to Mark K. for astronomical assistance.
For a good on-line primer on near stars, check out Winchell Chung's
(yeah, the same Winchell Chung who came up with the design for SJ Game's OGRE)
web site:
http://www.clark.net/pub/nyrath/starmap.html
Hope that helps.
Take care,
> Alternately, you can check out the Near Star List in 2300 AD, which
And I thought it was 'Joachim Heck'... ;-)
Who, btw, pointed me towards:
http://adac.mtk.nao.ac.jp/index.html
I haven't had any time to bring up a browser to look it over, so you
guys'll have to explore it w/out input from me. ;-)
Mk
Another source of information I've used it the book Proximity Zero. Details
can be found at:
http://www.peekaboo.net/tkepner/proximityzero.html
> Alan E & Carmel J Brain wrote:
> "Starforce Alpha Centauri" has a hex-grid map of a radius of all stars
My thoughts exactly. The map is a 3D sphere with star names, position, and
altitude on the Starforce map. It would be ideal for FT campaigns
in the game universe or a Sol-centered universe of your own making.
Some math is needed to move is 3D space for fleet movement, but that is
provided on the map sheet as well, I believe. I'll have to dig my map out of
storage.
> EPICS: Self-Guided Wilderness Tours wrote:
SPI many years ago brought out 2 space games, one a Wargame, the other (later)
one an RPG.
"Starforce Alpha Centauri" has a hex-grid map of a radius of all stars
about 20 LY from earth, with altitudes. So you get a 3-D map.
> At 02:01 PM 9/8/97 -0400, you wrote:
There are a number of writers guides for science fiction that include the same
calculations. I have at least two books with the surface temperature
calculation, and they are easier to find than the 2300AD game.