Date: Thu, 06 Oct 94 04:30:46 -0800 From: Edward_Swatschek@mindlink.bc.ca (Edward Swatschek) To: traveller@MPGN.COM Subject: Stars Message-ID: Someone asked a while back about the frequency of stars (or something along those lines). Here's a percentage break-down for main sequence stars: % ------ M 70 K 15 G 10 F 4 A 1 Some other useful stats: Steller density: 80 systems per 1000 cubic parsecs (average separation of 1.4 parsecs). Of the closest 26 star systems, 65% solitary (17) 17% binary (8) 4% trinary (1) Of those 36 stars, 92% main sequence (33) 8% white dwarf (3) Two of the three white dwarfs (DA) were part of binary systems, and circled the two most luminous stars (Sirius and Procyon). The final one is a solitary DG. Star Luminosity/Radius/Mass table. L R M -------------------------------- main sequence -------------------------------- O8 110 000 9.12 18 B0 46 000 11 14 B1 11 000 7.1 11 B2 5 300 5.8 8.9 B5 910 4.2 6.0 A0 54 2.0 2.8 A5 16 1.7 1.8 F0 7.1 1.5 1.4 F5 3.1 1.3 1.2 G0 1.6 1.1 1.1 G5 0.65 0.87 0.68 K0 0.28 0.66 0.60 K5 0.14 0.66 0.56 M0 0.059 0.60 0.50 M2 0.033 0.58 0.40 M4 0.012 0.38 0.28 Uncertain, because of M6 0.0019 0.17 0.13 the steepness of the main sequence -------------------------------- giants -------------------------------- G0 45 7.9 - Masses up to 4 K0 110 20 - Masses up to 4 M0 520 69 - Masses up to 4 -------------------------------- supergiants -------------------------------- B0 460 000 35 - All data have wide range A0 59 000 79 - All data have wide range K0 180 000 1100 - All data have wide range M0 460 000 2500 - All data have wide range L = Luminosty, relative to Sol; Sol = 3.9 x 10^26 W R = Radius, relative to Sol; Sol = 7.0 x 10^8 m M = Mass, relative to Sol; Sol = 2.0 x 10^30 kg (source: McGraw-Hill Encyclopedia of Science and Technology)