Distances to Stars

Distances are particularly easy to calculate if we use the parsec as our distance unit. In that case, the distance of a star in parsecs is just

D = 1/p where D is the distance in pc and p is the parallax angle in seconds of arc. For example, Sirius has a parallax angle of 0.38 seconds of arc and thus its distance from the Earth is d = 1/0.38 = 2.6 pc = 8.6 LY. The nearest star (other than the Sun) is the alpha-Centauri system, which has a parallax of 0.76 seconds of arc, corresponding to a distance of 1.315pc = 4.3 LY. Thus, all stars have parallax angles of less than one second of arc.

 Here is a table of distances to the nearest stars:-
 

The Nearest Stars Name Distance (LY) Spectral Type R.A. Dec. Luminosity (Solar Units) Proxima Centauri 4.2 M5V 14 30 -62 41 6 x 10-6 Alpha Centauri A 4.3 G2V 14 33 -60 50 1.5 Alpha Centauri B 4.3 K0V 14 33 -60 50 0.5 Barnard's Star 6.0 M4V 17 57 +04 33 4 x 10-4 Wolf 359 (Gliese 406) 7.8 M6V 10 56 +07 03 2 x 10-5 Lalande 21185 (HD 95735) 8.2 M2V 11 04 +36 02 5 x 10-3 Luyten 726-8 A 8.6 M5V 01 38 -17 58 6 x 10-5 Luyten 726-8 B (UV Ceti) 8.6 M6V 01 38 -17 58 4 x 10-5 Sirius A 8.6 A1V 06 45 -16 43 24 Sirius B 8.6 WD 06 45 -16 43 3 x 10-3 Ross 154 (Gliese 729) 9.6 M4V 18 50 -23 49 5 x 10-4 Ross 248 (Gliese 905) 10.3 M6V 23 42 +44 12 1 x 10-4 Epsilon Eridani 10.7 K2V 03 33 -09 27 0.3 Ross 128 (Gliese 447) 10.8 M4V 11 48 +00 49 3 x 10-4 Luyten 789-6 A1 11.1 M5V 22 39 -15 20 1 x 10-4 Luyten 789-6 B 11.1 - 22 39 -15 20 - Luyten 789-6 C 11.1 - 22 39 -15 20 - BD +43 44 A (Gliese 15 A) 11.3 M1V 00 18 +44 61 6 x 10-3 BD +43 44 B (Gliese 15 B) 11.3 M3V 00 18 +44 61 4 x 10-4 Epsilon Indi 11.3 K5V 22 03 -56 47 0.14 61 Cygni A 11.3 K5V 21 07 +38 45 0.008 61 Cygni B 11.3 K7V 21 07 +38 45 0.004 BD +59 1915 A (Gliese 725 A) 11.4 M3V 18 43 +59 37 0.003 BD +59 1915 B (Gliese 725 B) 11.4 M4V 18 43 +59 37 0.002 Tau Ceti 11.4 G8V 01 44 -15 56 0.45 Procyon A 11.4 F5IV 07 39 +05 13 7.7 Procyon B 11.4 WD 07 39 +05 13 6 x 10-4 CD -36 15693 (Locaille 9352) 11.5 M2V 23 06 -35 52 0.01 GJ 1111 (G51-15) 11.8 M7V 08 29 +26 47 1 x 10-5 GJ 1061 12.0 M5V 03 36 -44 30 8 x 10-5 Luyten 725-32 (YZ Ceti) 12.2 M5V 01 12 -18 04 3 x 10-4 BD +5 1668 (Gliese 273) 12.3 M4V 07 28 +05 17 0.001 CD -39 14192 (Gliese 825) 12.6 M0V 21 17 -38 52 0.03 Kapteyn's Star 12.6 M0V 05 11 -44 56 0.004