THE 172 BRIGHTEST STARS

Through Magnitude 3.00

From Jim Kaler's STARS.

The table lists the 172 visually brightest stars of the sky, those through visual magnitude 3.00 (that is, all the stars of the minus first, zeroth, first, and second magnitudes as seen with the naked eye, and extended to mid-third), adapted originally from the Cambridge Encyclopedia of Stars (J. B. Kaler, Cambridge University Press, 2006). Most data are taken from the Bright Star Catalogue (BSC, Fourth Revised Edition, D. Hoffleit and C. Jaschek, Yale University Observatory, New Haven, 1982) and SIMBAD . With some exceptions, distances are taken from the Hipparcos Catalogue, as are proper motions (motions across the line of sight). Distances of first magnitude (and brighter) stars are from the second reduction, as are some others as indicated in the stars' descriptions.

Magnitudes (hence rankings), colors (to determine the degree of interstellar dust absorption), and spectral classes are those of the BSC. In cases of ties in magnitudes, the stars are ranked from hottest to coolest. Many of the stars are binary (double) or even more complex. Close doubles are noted, wide ones ignored. Doubles unresolvable with the naked eye (ignoring faint companions) are ranked according to the combined magnitudes, with data on individuals given in the remarks. Note that listings such as this one cannot be unique and definitive because of stellar variability, different sources of data (which can give slightly different magnitudes), and different ways of treating binaries.

Several stars present special cases. The individual members of the Rigil Kentaurus (Alpha Centauri, ignoring Proxima), Capella (Alpha Aurigae), Hadar (Beta Centauri), and Acrux (Alpha Crucis) pairs would each make the list on their own. As a result, the table actually contains the 174 visually brightest stars. Castor A (which is itself double), at magnitude 1.93, would make the list as well, ranking 43rd, as would the brighter components of Spica, Mizar, Almach (Gamma And), Muhlifain (Gamma Cen), Algieba (Gamma Leo), and Graffias (Beta Sco). Because they are easily separable, the components of Rigil Kentaurus and Acrux are presented as individuals, though each is given the rank as if they were combined. Betelgeuse and Antares are variables that will change their brightness ranks. Outbursting Dschubba (Delta Scorpii) and Gamma Cassiopeiae are listed according to their catalogued magnitudes. Scheat (Beta Peg) can drop to third magnitude.

Statistics: Ignoring binaries, there are two stars of the minus first magnitude (brighter than -0.50, Canopus and Sirius), 8 of zeroth magnitude (between -0.49 and +0.50), 13 of first magnitude (between 0.51 and 1.50), and 70 of second magnitude (between 1.51 and 2.50). The number increases very rapidly with decreasing brightness, over 200 in third magnitude, and so on.

The table presents, in order:

• Rank (linked to the Constellation Maps);
• Proper name (linked to the star's story);
• Greek letter name (linked to a labelled photo of the star's constellation);
• Full Morgan-Keenan-Kellman spectral class (CLASS); (linked to the HR Diagram if star so located)
• Distance (DIST) in light years (those presented after July 1, 2009 using the second Hipparcos reduction);
• Apparent visual magnitude (APP MAG; combined for close double stars, binaries);
• Absolute visual magnitude (ABS MAG; what the apparent visual magnitude would be at a distance 32.6 light years), corrected for dimming by interstellar dust;
• Radial (line of sight) velocity (RAD VEL) in kilometers per second (negative indicating approach, positive recession;
• True speed (VEL; space velocity) in kilometers per second relative to the Sun;
• Remarks.

Opening image: Ursa Minor's Little Dipper, with Polaris at far left.