Star Info Page 3

Table of the Earth's Nearest Stars

distance	star	magnitude	spectral class	ascension	declination
.000016 ly	The Sun	-26.9	G2	.	-23 to +23
4.2 ly	Proxima Centauri .	11.3	M5e	14:30	-62:41
4.3 ly	Alpha Centauri A	.33	G0	14:40	-60:50
4.3 ly	Alpha Centauri B	1.70	K5	14:40	-60:50
5.96 ly	Barnard's Star	9.5	M5	17:58	+04:34
7.6 ly	Wolf 359	13.5	M6e	10:56	+07:01
8.11 ly	Lalande 21185	7.5	M2	11:03	+35:58
8.7 ly	Sirius A	-1.47	A0	06:45	-16:43
8.7 ly	Sirius B	8.3	white dwarf .	06:45	-16:43
8.93 ly	Luyten 726-8 A	12.5	M6e	01:39	-17:57
8.93 ly	Luyten 726-8 B	13	M6e	01:39	-17:57
9.4 ly	Ross 154	10.6	M5e	18:50	-23:50
10.3 ly	Ross 248	12.2	M6e	23:42	+44:10
10.7 ly	Epsilon Eridani	3.7	K2	03:33	-09:28
10.8 ly	Luyten 789-6	12.6	M6	22:38	-15:19
10.8 ly	Ross 128	11.1	M4	11:48	+00:48
11.1 ly	61 Cygni A	5.6	K5	21:07	+38:45
11.1 ly	61 Cygni B	6.3	K6	21:07	+38:45
11.3 ly	Epsilon Indi	4.7	K5	22:03	-56:47
11.4 ly	Procyon A	0.38	F5	07:39	+05:13
11.4 ly	Procyon B	10.7	white dwarf	07:39	+05:13
11.6 ly	Sigma 2398	9	m4	18:43	+59:38

A light year is the distance light travels in a year: 5,880,500,000,000 miles or 9 463 700 000 000 Kilometers. Distances to stars are difficult to measure accurately. There are a dozen stars at distances of 11-12 light years.

Magnitude is the measure of apparent brightness as seen from Earth, the larger the number the dimmer the star appears. A decrease of 1 in magnitude means the star appears two-and-a-half times as bright. A decrease of 2.5 in magnitude means the star appears 10 times as bright. Many stars have variable brightness. Stars with magnitudes beyond 6 are difficult to see without binoculars or a telescope.

The spectral class of a star attempts to determine its temperature, mass and size from its color and brightness. Most of these stars belong to the "main sequence" of star types.

Hours and minutes of right ascension are measured clockwise around Polaris, starting with the sun's position at the vernal equinox. One rotation = 24 hours. One hour = 60 minutes. The pointer stars of the big dipper are at 11 hours, Cassiopeia (the big W) is about 0 hours.

Declination (latitude) is measured in degrees and minutes of angle north (positive) and south (negative) from the equator. The declination of the north star, Polaris, is almost +90 degrees. One minute of right ascension is fifteen times as great an angle as one minute of declination.

The values given for ascension and declination are for January 2000. Stars move and the earth's axis precesses (wobbles), so these values will change slowly with time.