consteThe 26 Brightest Stars

Stellar Brightness

The Brightest Stars, as Seen from the Earth

Adapted from Norton's 2000.0, 18th edition (copyright 1989, Longman Group UK) with additional comments taken from Bill Baity's Sky Pages


Common Name Scientific Name Distance (light years) Apparent Magnitude Absolute Magnitude Spectral Type
Sun - -26.72 4.8 G2V
Sirius Alpha CMa 8.6 -1.46 1.4 A1Vm
Canopus Alpha Car 74 -0.72 -2.5 A9II
Rigil Kentaurus Alpha Cen 4.3 -0.27 4.4 G2V + K1V
Arcturus Alpha Boo 34 -0.04 0.2 K1.5IIIp
Vega Alpha Lyr 25 0.03 0.6 A0Va
Capella Alpha Aur 41 0.08 0.4 G6III + G2III
Rigel Beta Ori ~1400 0.12 -8.1 B81ae
Procyon Alpha CMi 11.4 0.38 2.6 F5IV-V
Achernar Alpha Eri 69 0.46 -1.3 B3Vnp
Betelgeuse Alpha Ori ~1400 0.50 (var.) -7.2 M2Iab
Hadar Beta Cen 320 0.61 (var.) -4.4 B1III
Acrux Alpha Cru 510 0.76 -4.6 B0.5Iv + B1Vn
Altair Alpha Aql 16 0.77 2.3 A7Vn
Aldebaran Alpha Tau 60 0.85 (var.) -0.3 K5III
Antares Alpha Sco ~520 0.96 (var.) -5.2 M1.5Iab
Spica Alpha Vir 220 0.98 (var.) -3.2 B1V
Pollux Beta Gem 40 1.14 0.7 K0IIIb
Fomalhaut Alpha PsA 22 1.16 2.0 A3Va
Becrux Beta Cru 460 1.25 (var.) -4.7 B0.5III
Deneb Alpha Cyg 1500 1.25 -7.2 A2Ia
Regulus Alpha Leo 69 1.35 -0.3 B7Vn
Adhara Epsilon CMa 570 1.50 -4.8 B2II
Castor Alpha Gem 49 1.57 0.5 A1V + A2V
Gacrux Gamma Cru 120 1.63 (var.) -1.2 M3.5III
Shaula Lambda Sco 330 1.63 (var.) -3.5 B1.5IV

Magnitudes

The magnitude scale was invented by an ancient Greek astronomer named Hipparchus in about 150 B.C. He ranked the stars he could see in terms of their brightness, with 1 representing the brightest down to 6 representing the faintest. Modern astronomy has extended this system to stars brighter than Hipparchus' 1st magnitude stars and ones much, much fainter than 6.

As it turns out, the eye senses brightness logarithmically, so each increase in 5 magnitudes corresponds to a decrease in brightness by a factor 100. The absolute magnitude is the magnitude the stars would have if viewed from a distance of 10 parsecs or some 32.6 light years. Obviously, Deneb is intrinsically very bright to make this list from its greater distance. Rigel, of nearly the same absolute magnitude, but closer, stands even higher in the list. Note that most of these distances are really nearby, on a cosmic scale, and that they are generally uncertain by at least 20%. All stars are variable to some extent; those which are visibly variable are marked with a "v".

What are apparent and absolute magnitudes? Apparent is how bright the appear to us in the sky. The scale is somewhat arbitrary, as explained above, but a magnitude difference of 5 has been set to exactly a factor of 100 in intensity. Absolute magnitudes are how bright a star would appear from some standard distance, arbitrarily set as 10 parsecs or about 32.6 light years. Stars can be as bright as absolute magnitude -8 and as faint as absolute magnitude +16 or fainter. There are thus (a very few) stars more than 100 times brighter than Sirius, while hardly any are known fainter than Wolf 356.

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