List of brightest stars

The apparent brightness of a star depends on both its inherent (absolute) luminosity and its proximity to the observer. Below are listed the 91 brightest individual stars in order of their apparent magnitudes in the visible spectrum as seen from Earth. This is not the same as a list of the brightest stars as seen with the naked eye, as close binary or multiple star systems will appear as a single star with an apparent magnitude greater than their individual components, e.g. the binary system Alpha Centauri has an apparent magnitude of -0.27, but the brightest individual star is Alpha Centauri A with the apparent magnitude as listed here of -0.01. Hence Alpha Centauri is the third brightest star in the night sky, whilst its brightest component Alpha Centauri A is the fourth brightest individual star. Stellar brightness in this selected table is limited to brighter than +2.50 magnitude, mostly as the available number of observable stars increases almost exponentially as the magnitude increases.^[1] To the naked eye on a clear dark night, the total number of stars visible is about 6,500. Stars visible through optical aid increase this even further. Telescopically, the entire night's sky has been mapped, photographed and catalogued almost completely down to 11th magnitude, and recent star surveys are continuing to catalogue much fainter stars.

For comparison, the non-stellar objects in our Solar System with maximum visible magnitudes less than +2.50 are the Moon (−12.92), Venus (−4.67), Jupiter (−2.94), Mars (−2.91), Mercury (−2.45), and Saturn (−0.49).

An exact order of the visual brightness of stars is not perfectly defined for the following reasons:

• The brightnesses of all stars were traditionally based on the apparent visual magnitude as perceived by the human eye, from the brightest stars of 1st magnitude to the faintest at 6th magnitude.
• The invention of the telescope and the discovery of double or binary stars meant that star brightness could be individual (separate) or total (combined).
• More and more accurate instrumental photometry differentiated stellar magnitudes, often changing the order of lists of brighter stars.
• Stellar magnitude is sometimes listed by the apparent brightness of stars as seen to the naked eye as if they were single stars, for example Norton's Star Atlas 18th Edition pg. 136.^[2]
• Other stellar magnitude lists (like this one) report individual stars, differentiating those in binary stars or double star systems. Often, the differences apply to the ten or hundred brightest stars. For example, the total or combined magnitude of: −0.27 for Alpha Centauri as 3rd, +0.08 for Capella as 6th, and +0.77 for Acrux as 13th.
• A third kind includes the Sun as first in the magnitude listings, making Sirius as 2nd, Canopus as 3rd, etc. Some, like this list, place the Sun at zero, as it is not a nighttime star.
• There are sometimes small statistical variations in measured magnitudes; however, for most of the brightest stars, accurate photometry means brightness stays unchanged. These particular stars are some times called standard stars, which appear in the Catalogues of Fundamental Stars like the FK4, FK5 or FK6.
• Some stars, like Betelgeuse and Antares, are variable stars, changing their magnitude over days, months or years. (In the Table, these are indicated with var.)

See also

• Lists of stars
• List of nearest stars
• List of nearest bright stars
• List of most luminous stars
• List of largest stars
• Historical brightest stars: the brightest star in Earth's night sky at each period within the last or next 5 million years
• List of constellations
• Lists of stars by constellation
• List of constellations by area
• List of nearest galaxies

References

External links

• 25 Brightest Stars, as Seen from the Earth
• The Brightest Stars at An Atlas of the Universe
• The Magnitude system
• About stellar magnitudes