General Stellar desity in our area of the Milky Way

[Proneutron]

According to astronomy.com, "The average stellar density here in the galactic disk is one star every 19 cubic parsecs, or about 5 light-years between stars."
That correlates with the 50% density per hex star gen method.

https://astronomy.com/magazine/ask-...e-can-stars-get-to-each-other-in-galaxy-cores

 

[Ulsyus]

According to astronomy.com, "The average stellar density here in the galactic disk is one star every 19 cubic parsecs, or about 5 light-years between stars."
That correlates with the 50% density per hex star gen method.

https://astronomy.com/magazine/ask-...e-can-stars-get-to-each-other-in-galaxy-cores

Isn’t one hex on a map a single parsec? Is there a 3D-to-2D ratio that’s been determined that’d allow some certainty around the density of systems you’d see in a section map?

 

[Proneutron]

Isn’t one hex on a map a single parsec?

Yes. And if two stars are 5 LYs apart they are two hexes apart.

 

[Timerover51]

Yes. And if two stars are 5 LYs apart they are two hexes apart.

So, on the average, to get anywhere from Terra to another star means either Jump-2 or two Jump-1.

 

[Grav_Moped]

So, on the average, to get anywhere from Terra to another star means either Jump-2 or two Jump-1.

Or the hex sizes are wrong, and should be 1.53 times larger.

 

[Timerover51]

Or the hex sizes are wrong, and should be 1.53 times larger.

Optionally, state that a Jump is from 5 to 30 Light Years, but can be shorter. Thirty light years would be slightly greater than 9 parsecs, so a Jump-6 drive would cover 9 hexes. A Jump-5 drive would cover 7 hexes. A Jump-4 would cover 6 hexes. A Jump-3 would cover 4 hexes. A Jump-2 would cover 3 hexes, and a Jump-1 would cover 1.5 hexes.

 

[Proneutron]

So, on the average, to get anywhere from Terra to another star means either Jump-2 or two Jump-1.

Yep. At 4.3 LYs (>1.3 parsecs) it's Alpha Centauri. A trinary I think.

 

[aramis]

Yep. At 4.3 LYs (>1.3 parsecs) it's Alpha Centauri. A trinary I think.

A binary central pair with a remote weakly bound distant companion at around 12,947 AU (about 0.205 LY). Proxima is also the most likely source of radio contact BLC1 (2020), aka "WOW! signal 2020". 980 MHz. See https://earthsky.org/space/wow-signal-2020-blc1-proxima-centauri

 

[Proneutron]

A binary central pair with a remote weakly bound distant companion at around 12,947 AU (about 0.205 LY). Proxima is also the most likely source of radio contact BLC1 (2020), aka "WOW! signal 2020". 980 MHz. See https://earthsky.org/space/wow-signal-2020-blc1-proxima-centauri

I just heard about that signal yesterday

 

[sudnadja]

Yep. At 4.3 LYs (>1.3 parsecs) it's Alpha Centauri. A trinary I think.

Note that at the time of the traveller (say 001-1105, 3605 years from now), Alpha Centauri A will be about 4.12 LY away and Proxima 4.00 LY.

 

[aramis]

THe density may be higher than listed if one counts the larger M10···M19 Brown Dwarf Stars (Also called Methane Dwarves and Class L0-L9 subdwarves), which have yet to be adequately searched for, and are bloody hard to detect without good IR scopes... which we're waiting on the right orbital scope to search for.`

I just heard about that signal yesterday

Friday, for me.

 

[Proneutron]

THe density may be higher than listed if one counts the larger M10···M19 Brown Dwarf Stars (Also called Methane Dwarves and Class L0-L9 subdwarves), which have yet to be adequately searched for, and are bloody hard to detect without good IR scopes... which we're waiting on the right orbital scope to search for.`



Friday, for me.

Merry Christmas.

Yes, can't wait 'till they can get a better population count in our neighborhood. Along with accurate temp readings.

 

[aramis]

Solstation.com's list of stars within 10 Pc from 2015...

Nearby Celestial Objects by Type, Number, and Mass

Spectral or Luminosity Type	Number within 10 Parsecs	Sum of Minimum Solar-Masses
O - Blue Stars	0	0.00
B - Blue White Stars	0	0.00
A - Bluish White Stars	4	8.7
F - Yellowish White Stars	8	8.9
G - Yellow-Orange Stars	20	18.5
K - Orange-Red Stars	42	29.9
M - Red Stars	273+	>38.4
M,L,T,Y - Brown Dwarfs	48+	<2.5
D - White Dwarfs	21+	>11.8
Total Objects Known	>413	>121

[tc=3][/tc]

and I know more M, L, and T have been found since. I doubt many more Bright stars will be.

 

[Proneutron]

Solstation.com's list of stars within 10 Pc from 2015...

Nearby Celestial Objects by Type, Number, and Mass

Spectral or Luminosity Type	Number within 10 Parsecs	Sum of Minimum Solar-Masses
O - Blue Stars	0	0.00
B - Blue White Stars	0	0.00
A - Bluish White Stars	4	8.7
F - Yellowish White Stars	8	8.9
G - Yellow-Orange Stars	20	18.5
K - Orange-Red Stars	42	29.9
M - Red Stars	273+	>38.4
M,L,T,Y - Brown Dwarfs	48+	<2.5
D - White Dwarfs	21+	>11.8
Total Objects Known	>413	>121

[tc=3][/tc]

and I know more M, L, and T have been found since. I doubt many more Bright stars will be.

Holy C! All within 10 parsecs I had no idea there was this many. ~10/ cubic parsec

 

[Ulsyus]

Holy C! All within 10 parsecs I had no idea there was this many. ~10/ cubic parsec

Doesn't that come out at 1 system per 11 cubic LY, or every 3^1/2 parsec hexes? I reckon this is where the difficulty of trying to accurately represent 3D space on a 2D map become apparent.

 

[Proneutron]

Doesn't that come out at 1 system per 11 cubic LY, or every 3^1/2 parsec hexes? I reckon this is where the difficulty of trying to accurately represent 3D space on a 2D map become apparent.

Correct. And, for sure. Would be nice to have real 3D holo-displays for gaming

 

[BRover]

Doesn't that come out at 1 system per 11 cubic LY, or every 3^1/2 parsec hexes? I reckon this is where the difficulty of trying to accurately represent 3D space on a 2D map become apparent.

Correct. And, for sure. Would be nice to have real 3D holo-displays for gaming

Yeah--and a 3-D Imperium could have a whole lot more systems, and still be a lot more compact. Even if you limited it to a 300pc depth--which, IIRC, is roughly the thickness of the galactic disk in our neighborhood.

 

[Proneutron]

Yeah--and a 3-D Imperium could have a whole lot more systems, and still be a lot more compact. Even if you limited it to a 300pc depth--which, IIRC, is roughly the thickness of the galactic disk in our neighborhood.

That would be awesome. Ya know, this could be done with a large monitor and some s/w (cough, cough, hint, hint, wink, wink).

 

[Straybow]

When considering how hard it is to pinpoint distance to very dim M stars and brown dwarfs, an allowance is made for stellar-like bodies that may be within 10 pc but haven't been discovered or placed with certainty. For stars within 5 pc, a much more complete survey with 63 stars and 78 total stellar-like bodies in 2018, that is more like 8 pc³ per star.

 

[G. Kashkanun Anderson]

Yeah--and a 3-D Imperium could have a whole lot more systems, and still be a lot more compact. Even if you limited it to a 300pc depth--which, IIRC, is roughly the thickness of the galactic disk in our neighborhood.

That is the scale height of the thin disk that you are referring to, so the actual thickness is double that. The thick disk extends an additional 1-1.5kpc above/below that, though by the time you get to that, navigation would get pretty challenging for any low to moderate jump craft.

Most measurements have the Sol system about 17-20 parsecs above the galactic plane. This places us in the junior varsity section of the galaxy (the young thin disk, <50pc above/below the galactic plane), despite the fact that ours is not a particularly young star at all.