Brightest Stars in Constellations

Alpheratz has a mass 3.8 times that of the Sun and a radius 2.7 times solar. It has a surface temperature of 13,800 K and is 240 times more luminous than the Sun. The estimated age of the star is 60 million years.

Alpheratz forms the Great Square of Pegasus with three stars in the constellation Pegasus, Scheat, Markab, and Algenib. The asterism outlines the main body of Pegasus, the Winged Horse.

Mirach (β Andromedae) is an evolved red giant (M0 III) with a mass of 2.49 solar masses and a radius 100 times that of the Sun. The star is 1,995 times more luminous than the Sun and has an effective temperature of 3,842 K. Its brightness varies from magnitude 2.01 to 2.10. Mirach lies 197 light-years away.

Sadalsuud and Sadalmelik form an asterism known as the Lightning Bolt with Deneb Algedi and Enif, the brightest stars in the constellations Capricornus and Pegasus. The asterism lies in the same area of the sky as the more prominent Great Square of Pegasus and the fainter Water Jar in Aquarius.

Altair is an exceptionally fast spinner. With a projected rotational velocity of 242 km/s, it completes a rotation in less than 8 hours (compared to the Sun’s rotation period of a little more than 25 days). The estimated age of Altair is 100 million years.

Altair forms the Shaft of Aquila with two relatively bright stars that flank it, Alshain and Tarazed. It is also part of the larger and brighter Summer Triangle, which it forms with Vega and Deneb, the brightest stars in the constellations Lyra and Cygnus.

Capella itself has a mass of 2.5687 solar masses and a radius 11.98 times that of the Sun. It is 78.7 times more luminous than the Sun with an effective temperature of 4,970 K. The estimated age of the system is between 590 and 650 million years.

Capella is part of two prominent asterisms. It forms Auriga’s hexagon with Menkalinan, Mahasim, Almaaz, and Hassaleh in Auriga, and Elnath in Taurus. It is also part of the Winter Circle, along with Sirius in Canis Major, Procyon in Canis Minor, Rigel in Orion, Aldebaran in Taurus, and Pollux in Gemini.

Arcturus is part of three spring asterisms. It appears at the base of the Kite, a pattern formed by the brightest stars in Boötes. The giant star also forms the Spring Triangle with Spica in Virgo and Regulus in Leo, and the Diamond of Virgo (the Great Diamond) with Spica, Denebola in Leo, and Cor Caroli in Canes Venatici.

Cor Caroli has a mass of 2.97 solar masses and a radius 2.5 times that of the Sun. With an effective temperature of 11,600 K, it shines with 101 solar luminosities. It has a binary companion, Alpha¹ CVn, at a separation of 19.6 arcseconds. The companion is an F-type main sequence star with an apparent magnitude of 5.60.

Cor Caroli is part of the Great Diamond, an asterism also formed by Arcturus in the constellation Boötes, Spica in Virgo, and Denebola at the Lion’s tail.

Sirius A has a white dwarf companion nicknamed the Pup. Sirius B is one of the most massive white dwarfs known. It has a mass of 1.02 solar masses packed into a volume comparable to the Earth’s.

Sirius forms the Winter Triangle with Betelgeuse in Orion and Procyon in Canis Minor. It is also part of the Winter Circle (Winter Hexagon), along with Capella in the constellation Auriga, Aldebaran in Taurus, Rigel in Orion, Procyon in Canis Minor, and Pollux in Gemini.

Procyon is one of the six first-magnitude stars that form the Winter Hexagon. The other five are Sirius, Aldebaran, Capella, Rigel, and Pollux. Procyon also forms the smaller Winter Triangle with Sirius and Betelgeuse. Both asterisms dominate the evening sky during the northern hemisphere winter.

Deneb Algedi forms the Lightning Bolt with the supergiants Enif in Pegasus and Sadalsuud and Sadalmelik in Aquarius.

The star is only slightly brighter than the F-type giant Caph (Beta Cassiopeiae, mag. 2.28). Both are occasionally outshone by the variable Gamma Cassiopeiae, normally the third brightest star in Cassiopeia.

Rigil Kentaurus and Toliman have a combined apparent magnitude of -0.27. Individually, they shine at magnitudes 0.01 and 1.33. Proxima Centauri, the nearest individual star to the solar system, appears 2.18 degrees southwest of the pair.

Rigil Kentaurus is a yellow dwarf with a mass of 1.078 solar masses and a radius of 1.2175 solar radii. Toliman is smaller and less massive. It is an orange dwarf with a mass of 0.9092 solar masses and a radius of 0.8591 solar radii. The estimated age of the system is about 5.3 billion years.

Rigil Kentaurus and Hadar (Beta Centauri) are known as the Southern Pointers. The two bright stars point toward the Southern Cross, an asterism used to find the southern celestial pole. Hadar, a hot blue giant in a triple star system, is the second-brightest star in Centaurus and the 11th-brightest star in the sky.

Alderamin can be found by extending a line from Schedar through Caph, the rightmost stars of Cassiopeia’s W. The luminary of Cepheus appears at the base of an asterism that looks like a stick house. It lies in the far northern sky and is one of the stars that take their turn as the North Star over the course of Earth’s axial precession cycle.

Phact forms an asterism called the Egyptian X with Naos, the brightest star in Puppis, and the stars of the Winter Triangle (Betelgeuse, Procyon, and Sirius).

Beta CrA is an orange giant or bright giant with a mass 5.17 times that of the Sun and a radius 38.5 times the Sun’s. The star is about 614 times more luminous than the Sun with an effective temperature of 4,575 K. It lies 470 light-years away.

Meridiana (α Coronae Australis) is an A-type main sequence star with a mass of 2.57 solar masses and a radius 2.21 times that of the Sun. With a surface temperature of 9,916 K, it is 31 times more luminous than the Sun. The star is a very fast spinner, with a projected rotational velocity of 195 km/s. It has an estimated age of 254 million years and lies 125 light-years away.

Acrux itself has a mass 17.8 times that of the Sun and a radius 7.8 times the Sun’s. It is 25,000 times more luminous than the Sun, shining at first magnitude from a distance of 320 light-years. It has the spectrum of a hot blue subgiant star. The star has a spectroscopic companion at a distance of only 1 astronomical unit.

Acrux forms the Southern Cross with Mimosa (Beta Crucis), Gacrux (Gamma Crucis), Imai (Delta Crucis), and Ginan (Epsilon Crucis). The asterism is commonly used to find true south. Mimosa and Gacrux, the second and third brightest stars in Crux, are the 20th and 25th brightest stars in the sky respectively.

Deneb marks the tail of the Swan and is the brightest of the five Cygnus stars that form the Northern Cross, one of the most recognizable asterisms in the northern sky. The supergiant also forms the Summer Triangle with the brighter Vega in the constellation Lyra and Altair in Aquila.

Deneb has a mass 19 times that of the Sun and a radius 203 times solar. It is about 196,000 times more luminous than the Sun, with an effective temperature of 8,525 K. The supergiant is the prototype for a class of variable stars known as the Alpha Cygni variables. These stars are A- and B-type supergiants that show small, irregular variations in brightness due to pulsations.

Rotanev is part of a small but distinctive asterism called Job’s Coffin, also formed by Alpha, Gamma, and Delta Delphini. The asterism outlines the body of the Dolphin.

The primary star has a mass 3.33 times that of the Sun and a radius 3.5 times solar. It shines with 195 solar luminosities with an effective temperature of 11,588 K. The companion has a mass 2.7 times that of the Sun and a radius of 1.9 solar radii. With a surface temperature of 12,200 K, it is 70 times more luminous than the Sun.

Eltanin has a mass of 1.72 solar masses and a radius 48.15 times that of the Sun. It shines with about 471 solar luminosities with an effective temperature of 3,930 K.

Kitalpha has a mass 2.3 times that of the Sun and a radius 9.2 times solar. It is 52.5 times more luminous than the Sun and has a surface temperature of 5,100 K. The companion has twice the Sun’s mass and a radius 2.6 times solar. With an effective temperature of 8,150 K, it is 26.3 times more luminous than the Sun.

Achernar is a hot blue main sequence star with a mass six times that of the Sun and a radius between 6.78 and 9.16 times solar. It is an exceptionally fast spinner, with a projected rotational velocity of 250 km/s. Due to its fast rotation, the star has an oblate shape. Its estimated age is 63 million years.

Achernar has a companion, an A-type main sequence star at a separation of 7.35 astronomical units. The companion has twice the Sun’s mass and is 17.5 times more luminous than the Sun.

Pollux, the brighter Twin, has a mass of 1.91 solar masses and a radius 9.06 times that of the Sun. It has a surface temperature of 4,586 K and shines with 32.7 solar luminosities. It is believed to be about 724 million years old.

The giant is one of the six first-magnitude stars that form the Winter Hexagon (Winter Circle), a bright, large asterism that dominates the evening sky during the northern hemisphere winter.

Kornephoros has a companion. The secondary component has a mass 90% that of the Sun. The two stars are locked in a 410.6-day orbit.

Kornephoros is about as bright as Zeta Herculis, the second brightest star in Hercules. Zeta Herculis is a multiple-star system located 35 light-years away. The primary component in the system is an F-type subgiant with a mass of 1.45 solar masses and an estimated age of 6.2 billion years.

Zeta Herculis forms the Keystone, an asterism that outlines the torso of Hercules, with Pi, Eta, and Epsilon Herculis. The asterism appears in the region between the bright Vega and Arcturus.

The name Alphard comes from the Arabic word for “the individual” or “the solitary one” and refers to the fact that there are no other exceptionally bright stars in this part of the sky. Alphard can be identified using the stars of the Sickle of Leo, a conspicuous asterism that represents the head and mane of the celestial Lion.

Regulus marks the Lion’s heart. It appears at the base of the Sickle of Leo, an asterism that outlines the head and mane of the celestial Lion. The star also forms the Spring Triangle with Arcturus in the constellation Boötes and Spica in Leo.

Regulus is a hot blue subgiant star located 79.3 light-years away. It is part of a multiple-star system that also includes a white dwarf, an orange dwarf, and a red dwarf. Regulus has a mass of 3.8 solar masses and a radius 4.35 times that of the Sun. With an effective temperature of 11,668 K, it shines with 316.2 solar luminosities. It has an estimated age of about 1 billion years.

The star is an exceptionally fast spinner, with a projected rotational velocity of 318 km/s. As a result, it has a highly oblate shape. It is flattened at the poles and has an equatorial bulge.

Together with Altair in the constellation Aquila and Deneb in Cygnus, Vega forms the Summer Triangle, a large, prominent asterism that dominates the northern summer sky. The star appears next to a parallelogram asterism that represents the lyre of Orpheus in Greek mythology.

Vega has a mass of 2.135 solar masses and a radius of 2.362 – 2.818 solar radii. The star’s equatorial radius is 19% larger than its polar radius because Vega is an exceptionally fast spinner and has an oblate shape. The temperature at its poles is higher – about 10,060 K – than at the equator – 8,152 K – because the poles are closer to the centre of mass.

Vega is about 40.12 times more luminous than the Sun. It has an estimated age of 455 million years. A candidate planet was detected orbiting the star in 2021.

Alpha Mensae has a companion, a red dwarf with a mass 16.9% that of the Sun and a radius 19% that of the Sun. The stars are separated by 3.05 arcseconds, corresponding to a physical distance of about 30 astronomical units.

Rasalhague has a mass of 2.40 solar masses and a radius 2.388 – 2.858 times that of the Sun. The star is a very fast spinner, with a projected rotational velocity of 240 km/s. As a result, it has an oblate shape and its equatorial radius is about 20% larger than its polar radius. With a surface temperature of 7,880 – 8,050 K, the giant is 25.1 – 25.6 times more luminous than the Sun. It has an estimated age of 0.77 billion years.

Rigel is classified as an Alpha Cygni variable. Its brightness has been observed to vary between magnitude 0.05 and 0.18. With a mass about 21 times that of the Sun, the star is a supernova candidate. It has a radius 78.9 times that of the Sun and is 120,000 times more luminous than the Sun, with an effective temperature of 12,100 K. The companions are less massive, with masses 3.84 (Ba), 2.94 (Bb), and 3.84 (C) times that of the Sun.

Rigel is the seventh brightest star in the sky. It is sometimes outshone by Betelgeuse (Alpha Orionis), a variable red supergiant at the shoulder of Orion. Betelgeuse is normally the second brightest star in Orion and the 10th brightest star in the sky.

Rigel marks the Hunter’s foot and is one of the six first-magnitude stars that form the Winter Circle, a large asterism that dominates the evening sky during the northern hemisphere winter.

Peacock is part of a spectroscopic binary system. The companion has a mass of at least 0.26 solar masses. The components have an orbital period of 11.753 days.

Enif is classified as a slow irregular variable. Its brightness is usually in the range from magnitude 2.37 to 2.45, but it has been observed to vary between magnitudes 0.7 and 3.5. On average, the star is only marginally brighter than Scheat (Beta Pegasi), a red giant or bright giant located 196 light-years away. Scheat is a semiregular variable with brightness oscillations in the range from 2.31 to 2.74. It is part of the Great Square of Pegasus.

Enif forms an asterism popularly known as the Lightning Bolt with Sadalsuud and Sadalmelik, the brightest stars in the constellation Aquarius, and Deneb Algedi, the lucida of Capricornus.

Mirfak has a mass 8.5 times that of the Sun and a radius 68 times solar. With an effective temperature of 6,350 K, it is about 5,000 times more luminous than the Sun. The star has an estimated age of 41 million years.

Fomalhaut is part of a wide triple star system with the orange dwarf TW Piscis Austrini and red dwarf LP 876-10. The primary component has a mass of 1.92 solar masses and a radius 1.842 times that of the Sun. It is 16.63 times more luminous than the Sun and has an effective temperature of 8,590 K. The star has an estimated age of about 440 million years.

Fomalhaut has a vast debris ring with an inner edge about 0.1 astronomical units from the star and outer edge at a radial distance of 133 astronomical units. The appearance of the ring in Hubble images has earned the star the nickname the Eye of Sauron.

The supergiant star has a mass 56.1 times that of the Sun and a radius between 14 and 26 solar radii. With a projected rotational velocity of over 220 km/s, it spins close to its breakup velocity and completes a rotation every 1.78 days. The star has an estimated age of only 3.2 million years, but it is at an advanced stage of its evolutionary cycle and will soon meet its end as a spectacular supernova.

Naos is part of the Egyptian X, a large asterism also formed by Phact, the brightest star in the constellation Columba, and the stars of the Winter Triangle (Sirius, Procyon, and Betelgeuse).

Kaus Australis has a mass 3.515 times that of the Sun and a radius 6.8 times solar. With a surface temperature of 9,960 K, it shines with 363 solar luminosities. It has an estimated age of 232 million years. The star is a very fast spinner, with a projected rotational velocity of 236 km/s. It has a binary companion, Epsilon Sagittarii B, at a physical separation of about 106 astronomical units.

The supergiant has a mass between 11 and 14.3 solar masses, which makes it a clear supernova candidate. It has a radius about 680 times that of the Sun and shines with 75,900 solar luminosities with a surface temperature of about 3,660 K. The estimated age of Antares is only about 15 million years.

The star has a binary companion, a hot blue main sequence star with a mass 7.2 times that of the Sun. The companion is an exceptionally fast spinner, with a projected rotational velocity of 250 km/s. The two stars are separated by about 2.6 – 2.8 arcseconds, which corresponds to a physical separation of about 529 astronomical units.

The giant star appears along the imaginary line extended from the three stars of Orion’s Belt. It is one of the six first-magnitude stars that form the Winter Circle, a large asterism that dominates the evening sky in the northern hemisphere during the winter months.

Aldebaran has a mass of 1.16 solar masses and a radius about 45.1 times that of the Sun. With a surface temperature of 3,900 K, it is 439 times more luminous than the Sun. The star is older than the Sun, with an estimated age of 6.4 billion years.

Polaris is the brightest of the seven Ursa Minor stars that form the Little Dipper. It marks the end of the Dipper’s handle and the tip of the Little Bear’s tail. The easiest way to find it is using the stars of the brighter Big Dipper. A line extended through the outer stars of the Big Dipper’s bowl (from Merak through Dubhe) leads to the North Star.

The star forms a triple star system with two F-type main sequence stars. It has a mass 5.4 times that of the Sun and a radius 37.5 times solar. With a surface temperature of 6,015 K, it is 1,260 times more luminous than the Sun. The supergiant star has an estimated age of 70 million years. It is classified as a classic Cepheid variable. Its brightness varies from magnitude 1.86 to 2.13. On average, Polaris is the 48th brightest star in the sky.

Gamma² Velorum is composed of a Wolf-Rayet star and a blue supergiant, while Gamma¹ contains a blue giant and a spectroscopic companion. The Wolf-Rayet star is the nearest and brightest star of its type to the Sun. It has a mass 9 times that of the Sun and a radius 6 times solar. With a surface temperature of 57,000 K, it is 170,000 times more luminous than the Sun. It has an estimated age between 3.5 and 5.5 million years. The O-type companion is a supergiant with a mass of 28.5 solar masses and a radius 17 times that of the Sun. With an effective temperature of 35,000 K, it shines with 280,000 solar luminosities. The two stars orbit each other with a period of 78.53 days at a separation that varies between 0.8 and 1.6 astronomical units.

The Gamma¹ Velorum pair has an orbital period of 1.48 days. The primary component is a blue-white giant and the companion is too close to it to be resolved optically.

Spica is a supernova candidate. It has a mass of 11.43 solar masses and a radius 7.47 times that of the Sun. With a surface temperature of 25,300 K, it is about 20,512 times more luminous than the Sun. It has an estimated age of only 12.5 million years. The star is an exceptionally fast spinner, with a projected rotational velocity of 165.3 km/s. It is classified as a Beta Cephei variable and a rotating ellipsoidal variable.

Spica appears at the base of the Y of Virgo, an asterism formed by the brightest stars in the Virgo constellation. The star is also part of two prominent seasonal asterisms. It forms the Spring Triangle with Arcturus in the constellation Boötes and Regulus in Leo and the Diamond of Virgo (Great Diamond) with Arcturus, Denebola in Leo, and Cor Caroli in Canes Venatici.

The giant star has a mass of 0.97 solar masses and a radius 43.14 times that of the Sun. With an effective temperature of 3,690 K, it shines with 415.9 solar luminosities.

The name Anser means “goose.” It is a reference to the old name of the constellation Vulpecula, Vulpecula cum Ansere (“the little fox with the goose”). The constellation was created by the Polish astronomer Johannes Hevelius in the 17th century.