Brightest stars

There are 15 bright (first magnitude) stars visible from all of the United States. There is something worth remembering about all 15, as listed in this table in order of brightness. All of these are much brighter intrinsically than the sun, which would only appear as an average (4th magnitude) star in our sky.

The Fifteen Brightest Stars Visible in U.S.A.
Name Location Apparent magnitude Absolute magnitude Distance (ly) What to Remember
Sun (Sol)   -26 4.83 1/60,000  
1. Sirius A Canis Major (Big Dog) -1.47 1.42 8.6 Appears to be the brightest of all stars because it is nearest of those on this list. It is white, but before Christ it was called red. Has white dwarf companion.
Canopus   -0.72 -5.53 330 Canopus is a supergiant, the brightest star in the southern constellation of Carina and the second brightest star in the night-time sky, after Sirius. It is a circumpolar star when viewed from points south of latitude 38 South, roughly that of Melbourne in Australia, or Wellington in New Zealand. To anyone living in the northern hemisphere, but far enough south to see the star, it served as a southern pole star until magnetic compasses became common.
Alpha Centauri A Centaurus -0.01 4.38 4.4 Although it appears as a single point to the naked eye, Alpha Centauri is actually a system of three stars, one of which is the fourth brightest star in the night sky. Alpha Centauri is famous in the Southern Hemisphere as the outermost "pointer" to the Southern Cross, but it is too far south to be visible in most of the northern hemisphere.
2. Arcturus Boötes (Herdsman) -0.04 var -0.29 37 To find, follow "arc" of Big Dipper. Orange Giant. Second brightest star visible from northern latitudes.
3. Vega Lyre 0.03   25 Nearby White Main Sequence. In summer Triangle. Vega was the first star other than the Sun to be photographed and the first to have its spectrum recorded. Was the North Star about 14,000 years ago.
4. Capella A/B Charioteer 0.71/0.96 -0.5 42 A pair of yellow giants, closer to the north celestial pole than any other first magnitude star (Polaris is only second magnitude). Nearly always above horizon. In Greek mythology, Capella is the goat that suckled baby Zeus and whose horn became the Horn of Plenty (Cornucopia). In Hindu mythology, Capella was seen as the heart of Brahma. The star is also often labelled "the shepherd's star" in English literature.
5. Rigel A Foot of Orion 0.12 -6.7 770 Very Distant Blue supergiant: greatest true brightness on this list. Dominates our Orion arm of our Galaxy.
6. Procyon A Canis Minor (Little Dog) 0.34 2.65 11 Near Sirius and 2nd closest on this list. Also has white dwarf companion, like Sirius. Its name comes from the Greek προκύον (prokúon), meaning "before the dog", since it precedes the "Dog Star" Sirius as it travels across the sky as the Earth rotates. These two dog stars are referred to in the most ancient literature and were venerated by the Babylonians and the Egyptians. Forms the Winter Triangle, along with Sirius and Betelgeuse. Procyon is also part of another asterism, the Winter Hexagon, which also includes Sirius, Rigel, Aldeberan, Capella, and Pollux.
7. Betelgeuse Shoulder of Orion 0.58 var -5.14 430 Huge red supergiant, the size of the orbit of Jupiter. In Orion cluster with Rigel and on the celestial equator.
8. Altair Head of the Eagle 0.77 2.2 17 Nearby White Main Sequence. 12th brightest star in the sky. Part of the Summer Triangle, along with Vega and Deneb.
9. Aldebaran Eye of Taurus, the Bull 0.85 var -0.63/12 65 Red Giant in the eye of Taurus, hence "Bull's Eye". 13th brightest star in the sky. One of 4 royal stars near ecliptic.
10. Antares Heart of the Scorpion (Scorpio) 1.09   600 Red Supergiant, almost as large as Betelgeuse. One of 4 royal stars near ecliptic, in the "Heart of the Scorpion".
11. Spica Virgo, Keep following arc past Acturus 1.04   260 Binary star with a period of only 4 days, Blue Main Sequence, just below ecliptic. Spica makes it easy to locate Virgo, as it can be found by following the curve of the Big Dipper to Arcturus in Boötes and continuing from there in the same curve ("follow the arc to Arcturus and speed on to Spica").
12. Pollux Head of Gemini (Twins) nearest ecliptic 1.15   34 Orange Giant just above ecliptic. The other twin is Castor, which just missed being in top 15 (it's #17).
13. Fomalhaut Southern Fish 1.16   25 One of 4 royal stars; somewhat below the ecliptic.
14. Deneb Tail of the Swan 1.25   3200 The most distant on this list: 1,500 l.y.; one of the brightest stars intrinsically. In summer triangle.
15. Regulus Heart of the Lion 1.35   77 Leader of 4 royal stars, almost exactly on ecliptic.
Castor Gemini 1.96   52  
 

Note: Venus is a planet but often mistaken for a bright star. It is by far the brightest celestial object in the sky after the Sun and Moon. It is called morning star or evening star because of its relatively tight orbit around the Sun. Mercury is also a morning/evening star, but is much dimmer and only visible for a few weeks of the year.
 

Royal stars

The four Royal stars or Guardians of the Sky were a group of stars noticed by the Persian astrologers around 3000 BC and used as a rudimentary season calendar. All four stars are among the brightest 25 stars, having an apparent magnitude of less than 1.5. However, this particular set of stars was chosen because they all lie close to the ecliptic and are divided on the sky by approximately 6 hours apart in right ascension. They are called "royal" because they appear to stand aside from the other stars in the sky. Throughout a year, each star is for several months "dominant" on the night sky and one can guess the season just by noticing which star is dominant.

The four stars with their modern and ancient Persian names were:

 

Dimmer stars

Besides the fifteen bright (first magnitude) stars listed above, there are several other stars worth knowing by name, even though they are not the brightest stars in the sky.

Dimmer Stars Worth Knowing
Name Location What to Remember
Polaris Little Bear The Pole Star, so-called because it is currently within 1° of the North Celestial Pole. A second magnitude Cepheid variable. It can be found by using the stars Dubhe and Merak, the "Pointer Stars" of the Big Dipper.
Mizar Ursa Major (Big Bear) The star at the bend in the handle of the Big Dipper. This star is three kinds of double stars in one. First it makes an optical double star with Alcor, a faint blue star that most people can see very near it in a dark sky. It is also a fine visual binary visible in a small telescope. The primary of that pair is also the first spectroscopic double which was discovered.
Kochab Lesser Bear The four stars in the bowl of the Little Dipper are of 2nd, 3rd, 4th and 5th magnitude, so they form a nice set of measuring standards. Kochab is the brightest of them. The name means "star" in Arabic, being short for "al Kaukab ash-Shamali" meaning "North Star," which it was from 1500 B.C. to A.D. 300.
Thuban Lyre This star is easily found because it is nearly midway between Mizar and Kochab. It served as the Pole Star in ancient Egypt. Drawing a circle through it, Polaris and Vega shows the path of the North Celestial Pole over its 26,000 year cycle.
Algol Head of Medusa, in Perseus Known as "The Demon Star" (from Arabic "Ras al Ghul," whence our word "Ghoul" derives). It represented the decapitated head of the snake-haired Medusa, which Perseus is carrying in a pouch. It is an eclipsing binary which dims one full magnitude in brightness about every three days when the larger dimmer star obscures the brighter.
Alcyone in the Pleiades (the Seven Sisters) in The Bull The brightest of the Seven Sisters. This group has had great significance to many nations around the globe. The other sisters names are Maia, Electra, Merope, Taygeta, Celeno and Sterope, being the daughters of Atlas and Pleione. They are a nearby open cluster of about a hundred blue stars which is 2° across, a spectacular sight in binoculars.
Bellatrix Shoulder of Orion The name is Latin for "The Female Warrior", and it is sometimes called the Amazon Star.
Mintaka Orion's Belt Meaning "Belt," it is the western star of Orion's belt. All three belt stars are type O-B supergiants, about 30,000° surface temperature; over 10,000 times brighter than the Sun. Mintaka is almost exactly on the celestial equator.
Dubhe Big Bear The "Pointer Star" of the Big Dipper which is nearest to Polaris. The name means "Bear" in Arabic. The other pointer star is named Merak. Merak is part of the nearby star cluster that most of the Big Dipper stars are in, but Dubhe is not in the cluster.
Castor Twins The name both of the other Twin (along with Pollux) as well as the star representing his head. It is a beautiful close double star, the first binary star discovered (it requires a 6" telescope). It is really a triple star, each member of which is a spectroscopic binary, so there are at least six stars in the system.
Albireo Cygnus Perhaps the most beautiful double star, having blue and gold components. Easy to separate in any telescope.
Caph Cassiopeia The star on the right side of the "W" of Cassiopeia. It is almost exactly on the 0 hour line of right ascension, so it culminates at 0 hours sidereal time.
Delta Cephei Cepheus The first Cepheid variable discovered, for which they are named. Cepheids pulsate in brightness, with the period being directly related to their intrinsic luminosity. It change in brightness by nearly a full magnitude in 5 days. It is also a beautiful double star in binoculars.
Mira Cetus Its name meaning "Wonderful", this "Miracle Star" is a long term variable which changes from 3rd to 10th magnitude (barely visible in binoculars) in 330 days. Its luminosity changes between 1 and 10,000 times the brightness of the sun.
Almach Andromeda One of the most beautiful double stars, having yellow-orange and blue-green components.
Mirfak Perseus The brightest star in Perseus is in the center of a beautiful field of stars as seen in binoculars. They are an "association" which is like a cluster, but so loosely bound that is not held together by gravity.
Cor Caroli Andromeda A lovely double star with yellow components which can be seen in a 2" telescope.
Sheliak Lyra Also called Beta Lyrae, this star is one of the most interesting to astronomers. It is an eclipsing binary with a 13 day period, with a half-magnitude variation which can be observed visually by comparison to the star next to it. It has bright emission lines and is expelling matter so quickly that its orbital period is changing rapidly.
Eltanin Draco Meaning "the serpent" in Arabic, this star is the eye of the Dragon. It and the other four stars in the head make good standards for 2nd, 3rd, 4th and 5th magnitude stars. Eltanin is useful to know because it has right ascension of 18h, and is circumpolar for many, so it can be used to tell sidereal time.
Rasalgethe Hercules Meaning the "head of the kneeler," it is a beautiful orange and green binary star, but it requires at least an 8" telescope to resolve it. The dimmer member is again a spectroscopic binary. The brighter member is a red giant which varies erratically in brightness from 3rd to 4th magnitude in 50-130 days. It is ejecting great quantities of mass which envelop the entire system.
 

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