08-11-2022, 03:51 PM | #1 |
Join Date: Aug 2014
Location: Canada
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Number of habitable worlds within170 light years?
Hi,
I know nobody can really answer this with true certainty, but what do you think a reasonable amount of habitable worlds would be to place in a campaign if you traveled in every direction up to 170 light years away?
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Oliver. |
08-11-2022, 04:33 PM | #2 |
Join Date: Apr 2019
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Re: Number of habitable worlds within170 light years?
There are more than 60 G-type stars (like Sol) within 50 parsecs (just under 170 ly) from Earth:
http://www.solstation.com/stars3/100-gs.htm There are many many many M-type stars (Red Dwarfs likely to have habitable zones) within 50 parsecs. It's up for debate, though, whether these stars are really likely to have habitable worlds: http://www.solstation.com/stars3/100-ms.htm#40-50 And maybe the likeliest to have habitable worlds are K-type stars, with an estimated >200 within 50 ly and maybe as many as 2,000 within 100 ly. http://www.solstation.com/stars3/100-ks.htm Hope these pages help! EDIT: In other words, probably far, far more than it would be possible to stat for any playable game! Guesstimate 10% of these stars host habitable worlds and you're still looking at more than a thousand habitable worlds within 50 parsecs at the very least. Last edited by JulianLW; 08-11-2022 at 04:37 PM. |
08-11-2022, 04:41 PM | #3 |
Join Date: May 2005
Location: Oz
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Re: Number of habitable worlds within170 light years?
I ran the GURPS Space generator over data from the XHIP catalogue. Disregarding a lot of synchronously-rotating planets of M and late K stars that I didn’t think would actually be habitable, and adopting a somewhat higher bar for habitability than the standard Habitability rating, I got one thousand habitable planets within 175 light years.
That’s optimistic, but not incredible.
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Decay is inherent in all composite things. Nod head. Get treat. Last edited by Agemegos; 08-12-2022 at 01:02 AM. Reason: typing errors, including “155” for “175” |
08-11-2022, 04:44 PM | #4 | |
Join Date: Aug 2014
Location: Canada
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Re: Number of habitable worlds within170 light years?
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Oliver. |
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08-11-2022, 04:44 PM | #5 | |
Join Date: Aug 2014
Location: Canada
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Re: Number of habitable worlds within170 light years?
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Oliver. |
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08-11-2022, 06:15 PM | #6 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: Number of habitable worlds within170 light years?
A lot depends on your definition of habitable, and on some assumptions (I would note that Earth has not been human-habitable for most of its lifespan, and we have far less information about alien planets)
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08-11-2022, 08:23 PM | #7 |
Join Date: Jun 2006
Location: On the road again...
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Re: Number of habitable worlds within170 light years?
I use K, G, and F type stars for hunting down habitable worlds. A generous estimate is likely to be 50% of the stars have a planet in the habitable zone, with 50% of those planets being habitable without some form of terraforming.
That said, in my own space opera setting I have a habitable planet in each of those that has a stable zone (F types with orbiting white dwarfs - like Procyon - don't count) - and even those whose planets aren't habitable still get inhabited by humans in pressure domes. So even the M-types are inhabited, even if not inhabitable. (A-types like Vega aren't likely to have habitable planets, due to being too young, if they have planets in the first place.)
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08-11-2022, 08:29 PM | #8 |
Join Date: May 2019
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Re: Number of habitable worlds within170 light years?
Fascinating! Why 170 ly? Can we scale up these numbers to larger regions? What's the percentage of stars in the galaxy that would have habitable planets, using these same assumptions? (I'm presuming the core might have a lower percentage of habitable systems...).
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08-11-2022, 09:05 PM | #9 |
Join Date: Aug 2004
Location: Seattle, WA USA
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Re: Number of habitable worlds within170 light years?
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08-12-2022, 01:06 AM | #10 | |
Join Date: May 2005
Location: Oz
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Re: Number of habitable worlds within170 light years?
Quote:
Little thing like that!
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