"Winter Triangle and the Circle. Orion's seven brightest stars form a distinctive hourglass-shaped asterism, or pattern, in the night sky. Four stars—Rigel, Betelgeuse, Bellatrix and Saiph—form a large roughly rectangular shape, in the centre of which lie the three stars of Orion's Belt—Alnitak, Alnilam and Mintaka. Descending from the 'belt' is a smaller line of three stars, Orion's Sword (the middle of which is in fact not a star but the Orion Nebula), also known as the hunter's sword. Many of the stars are luminous hot blue supergiants, with the stars of the belt and sword forming the Orion OB1"
"is now so entered in the IAU Catalog of Star Names. The apparent visual magnitude of Rigel is 0.13, making it on average the seventh-brightest star in the celestial sphere excluding the Sun—just fainter than Capella. It is an irregular pulsating variable with a visual range of magnitude 0.05–0.18. Although Rigel has the Bayer designation ""beta"", it is almost always brighter than Alpha Orionis (Betelgeuse). Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. Rigel is the third most inherently luminous first magnitude star after Deneb and"
"Alpha Reticuli Alpha Reticuli (Alpha Ret, α Reticuli, α Ret) is the Bayer designation of the brightest star in the southern circumpolar constellation of Reticulum, with an apparent visual magnitude of 3.3. This appears to be a solitary star located at a distance of 162 light-years from Earth. Although it is bright enough to be seen with the naked eye, the declination of this star means that it is best viewed from the southern hemisphere and is only readily visible below the tropic of cancer. This star has more than three times the mass of the Sun and is about"
"of its proximity to the Solar System. In contrast, the other bright stars of the constellation are stars of great distance and high luminosity. At magnitude 1.5, Epsilon Canis Majoris (Adhara) is the second-brightest star of the constellation and the brightest source of extreme ultraviolet radiation in the night sky. Next in brightness are the yellow-white supergiant Delta (Wezen) at 1.8, the blue-white giant Beta (Mirzam) at 2.0, blue-white supergiants Eta (Aludra) at 2.4 and Omicron at 3.0, and white spectroscopic binary Zeta (Furud), also at 3.0. The red hypergiant VY Canis Majoris is one of the largest stars known,"
"Deneb Deneb (), also designated α Cygni (Latinised alpha Cygni, abbreviated Alpha Cyg, α Cyg), is the brightest star in the constellation of Cygnus, the swan. It is one of the vertices of the asterism known as the Summer Triangle and forms the 'head' of the Northern Cross. It is the 19th brightest star in the night sky, with an apparent magnitude of 1.25. A blue-white supergiant, Deneb is also one of the most luminous stars. However, its exact distance (and hence luminosity) has been difficult to calculate; it is estimated to be somewhere between 55,000 and 196,000 times as"
"element, the constellation was not an integral part of the old Argo Navis and hence did not share in the original Bayer designations of that constellation, which were split between Carina, Vela and Puppis. Pyxis is a faint constellation, its three brightest stars—Alpha, Beta and Gamma Pyxidis—forming a rough line. Overall, there are 41 stars within the constellation's borders with apparent magnitudes brighter than or equal to 6.5. With an apparent magnitude of 3.68, Alpha Pyxidis is the brightest star in the constellation. Located 880 ± 30 light-years distant from Earth, it is a blue-white giant star of spectral type"
"Regulus Regulus, also designated Alpha Leonis (α Leonis, abbreviated Alpha Leo, α Leo), is the brightest star in the constellation of Leo and one of the brightest stars in the night sky, lying approximately 79 light years from the Sun. Regulus is a multiple star system composed of four stars that are organized into two pairs. The spectroscopic binary Regulus A consists of a blue-white main-sequence star and its companion, which has not yet been directly observed, but is probably a white dwarf. Located farther away are Regulus B, C, and D, which are dim main-sequence stars. ""α Leonis"" (Latinized"
"is the most luminous in our local region of the Milky Way; at about 71 times the diameter of the Sun it would, if viewed from a hypothetical planet at a distance of 1 AU, subtend an angle of 35° in the sky—when rising or setting it would extend from the horizon almost halfway up the sky—and it would shine at a lethal magnitude of −38 (see graphic). There is no evidence that the Rigel system hosts any extrasolar planets. However, several creators of works of science fiction have chosen to populate it with an unusually large family of worlds"
"Alpha Fornacis Alpha Fornacis (α Fornacis, abbreviated Alpha For, α For), also designated 12 Eridani, is a binary star system in the southern constellation of Fornax. It is the brightest star in the constellation and the only one brighter than magnitude 4.0. Based on parallax measurements obtained during the Hipparcos mission, it is approximately 46 light-years (14 parsecs) distant from the Sun. Its two components are designated Alpha Fornacis A (also named Dalim) and B. ""α Fornacis"" (Latinised to ""Alpha Fornacis"") is the system's Bayer designation, ""12 Eridani"" its Flamsteed designation. The designations of the two components as ""Alpha Fornacis"
"(not shown on the main map as it is located below the map's southeastern corner, north is up). Instead, the brightest star is Epsilon Sagittarii (ε Sgr) (""Kaus Australis,"" or ""southern part of the bow""), at magnitude 1.85. Sigma Sagittarii (σ Sgr) (""Nunki"") is the constellation's second-brightest star at magnitude 2.08. Nunki is a B2V star approximately 260 light years away. ""Nunki"" is a Babylonian name of uncertain origin, but thought to represent the sacred Babylonian city of Eridu on the Euphrates, which would make Nunki the oldest star name currently in use. Zeta Sagittarii (ζ Sgr) (""Ascella""), with apparent"
"Lion:the King."" Regulus Regulus, also designated Alpha Leonis (α Leonis, abbreviated Alpha Leo, α Leo), is the brightest star in the constellation of Leo and one of the brightest stars in the night sky, lying approximately 79 light years from the Sun. Regulus is a multiple star system composed of four stars that are organized into two pairs. The spectroscopic binary Regulus A consists of a blue-white main-sequence star and its companion, which has not yet been directly observed, but is probably a white dwarf. Located farther away are Regulus B, C, and D, which are dim main-sequence stars. ""α"
"Spica Spica, also designated Alpha Virginis (α Virginis, abbreviated Alpha Vir, α Vir), is the brightest star in the constellation of Virgo and one of the 20 brightest stars in the night sky. Analysis of its parallax shows that it is located 250 ± 10 light years from the Sun. It is a spectroscopic binary and rotating ellipsoidal variable; a system whose two main stars are so close together they are egg-shaped rather than spherical, and can only be separated by their spectra. The primary is a blue giant and a variable star of the Beta Cephei type. Spica, along"
"Betelgeuse Betelgeuse, also designated Alpha Orionis (α Orionis, abbreviated Alpha Ori, α Ori), is on average the ninth-brightest star in the night sky and second-brightest in the constellation of Orion. It is distinctly reddish, and is a semiregular variable star whose apparent magnitude varies between 0.0 and 1.3, the widest range of any first-magnitude star. Betelgeuse is one of three stars that make up the asterism of the Winter Triangle, and it marks the center of the Winter Hexagon. If the human eye could view all wavelengths of radiation, Betelgeuse would be the brightest star in the night sky. Classified"
"on the outskirts of the massive Cygnus OB2 association, the detectable effects of NML Cygni's radiation on the surrounding dust and gas are limited to the region away from the central hot stars of the association. NML Cygni NML Cygni or V1489 Cygni is a red hypergiant (RHG) or red supergiant (RSG) in the constellation Cygnus. It is one of the largest stars currently known, and is also one of the most luminous and massive cool hypergiants, as well as one of the most luminous stars in the Milky Way. If placed at the center of the Solar System, its"
"that the coordinates were mistranscribed 32 in error by Flamsteed and in fact referred to 7.4 magnitude HD 10407. Baily also noted that 16 Trianguli was closer to Aries and included it in the latter constellation. Three stars make up the long narrow triangle that gives the constellation its name. The brightest member is the white giant star Beta Trianguli of apparent magnitude 3.00, lying 127 light-years distant from Earth. It is actually a spectroscopic binary system; the primary is a white star of spectral type A5IV with 3.5 times the mass of our sun that is beginning to expand"
"is the third-brightest star in the constellation Cygnus, is actually a close binary itself. Also in the Cygnus constellation is Cygnus X-1, an X-ray source considered to be a black hole. It is a high-mass X-ray binary, with the optical counterpart being a variable star. Sirius is another binary and the brightest star in the night time sky, with a visual apparent magnitude of −1.46. It is located in the constellation Canis Major. In 1844 Friedrich Bessel deduced that Sirius was a binary. In 1862 Alvan Graham Clark discovered the companion (Sirius B; the visible star is Sirius A). In"
"Pictor Pictor is a constellation in the Southern Celestial Hemisphere, located between the star Canopus and the Large Magellanic Cloud. Its name is Latin for painter, and is an abbreviation of the older name Equuleus Pictoris (the ""painter's easel""). Normally represented as an easel, Pictor was named by Abbé Nicolas-Louis de Lacaille in the 18th century. The constellation's brightest star is Alpha Pictoris, a white main-sequence star around 97 light-years away from Earth. Pictor also hosts RR Pictoris, a cataclysmic variable star system that flared up as a nova, reaching apparent (visual) magnitude 1.2 in 1925 before fading into obscurity."
"Alpha Vulpeculae Alpha Vulpeculae (α Vulpeculae, abbreviated Alf Vul, α Vul), also named Anser, is the brightest star in the constellation of Vulpecula. It is approximately 297 light-years from Earth. It forms a wide optical binary with 8 Vulpeculae. Alpha Vulpeculae is a red giant of spectral class M1 and has apparent magnitude +4.4. It has been analysed as a member of the Arcturus stream, a group of stars with high proper motion and metal-poor properties thought to be the remnants of a small galaxy consumed by the Milky Way. ""α Vulpeculae"" (Latinised to ""Alpha Vulpeculae"") is the system's Bayer"
"the Rush albums ""A Farewell to Kings"" and ""Hemispheres"", the """" computer game, ""Stellaris"", science fiction novel ""Hyperion"", and Andy Weir, in his novel ""The Martian"". Deneb Deneb (), also designated α Cygni (Latinised alpha Cygni, abbreviated Alpha Cyg, α Cyg), is the brightest star in the constellation of Cygnus, the swan. It is one of the vertices of the asterism known as the Summer Triangle and forms the 'head' of the Northern Cross. It is the 19th brightest star in the night sky, with an apparent magnitude of 1.25. A blue-white supergiant, Deneb is also one of the most"
"Epsilon Pegasi Epsilon Pegasi (ε Pegasi, abbreviated Epsilon Peg, ε Peg), also named Enif (EE-nif), is the brightest star in the northern constellation of Pegasus. With an apparent visual magnitude of 2.4, this is a second-magnitude star that is readily visible to the naked eye. The distance to this star can be estimated using parallax measurements from the Hipparcos astrometry satellite, yielding a value of around . ""ε Pegasi"" (Latinised to ""Epsilon Pegasi"") is the star's Bayer designation. It bore the traditional name ""Enif"" derived from the Arabic word for 'nose', due to its position as the muzzle of Pegasus."
"are defined by a 17-sided polygon. In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between and . The International Astronomical Union (IAU) adopted the three-letter abbreviation ""Lyr"" for the constellation in 1922. The brightest and by far the most well-known star in the constellation is Vega, a main-sequence star of spectral type A0Va. Only 7.7 parsecs distant, is a Delta Scuti variable, varying between magnitudes −0.02 and 0.07 over 0.2 days. On average, it is the second-brightest star of the northern hemisphere (after Arcturus) and the fifth-brightest"
"regard it as the chief of all the stars. Rehua is father of ""Puanga/Puaka"" (Rigel), an important star in the calculation of the Māori calendar. The Wotjobaluk Koori people of Victoria, Australia, knew Antares as ""Djuit"", son of ""Marpean-kurrk"" (Arcturus); the stars on each side represented his wives. The Kulin Kooris saw Antares (""Balayang"") as the brother of ""Bunjil"" (Altair). Antares Antares (), also designated Alpha Scorpii (α Scorpii, abbreviated Alpha Sco, α Sco), is on average the fifteenth-brightest star in the night sky, and the brightest star in the constellation of Scorpius. Distinctly reddish when viewed with the naked"
"remain in use, likely because of their proximity to the north celestial pole. Within the constellation's borders, there are 39 stars brighter than or equal to apparent magnitude 6.5. Marking the Little Bear's tail, Polaris, or Alpha Ursae Minoris, is the brightest star in the constellation, varying between apparent magnitude 1.97 and 2.00 over a period of 3.97 days. Located around 432 light-years away from Earth, it is a yellow-white supergiant that varies between spectral types F7Ib and F8Ib, and has around 6 times the Sun's mass, 2,500 times its luminosity and 45 times its radius. Polaris is the brightest"
"NML Cygni NML Cygni or V1489 Cygni is a red hypergiant (RHG) or red supergiant (RSG) in the constellation Cygnus. It is one of the largest stars currently known, and is also one of the most luminous and massive cool hypergiants, as well as one of the most luminous stars in the Milky Way. If placed at the center of the Solar System, its surface would extend past the orbit of Jupiter or Saturn. The distance of NML Cygni from Earth is estimated to be around 1.6 kpc, about 5,300 light-years. It is a part of the Cygnus OB2 association,"
"mentally draw a line from the Pleiades star cluster located in Taurus and the brightest star in Leo, Regulus. In doing so, an imaginary line that is relatively close to the ecliptic is drawn, a line which intersects Gemini roughly at the midpoint of the constellation, just below Castor and Pollux. The constellation contains 85 stars visible to observation on Earth without a telescope. The brightest star in Gemini is Pollux, and the second-brightest is Castor. Castor's Bayer designation as ""Alpha"" arose because Johann Bayer did not carefully distinguish which of the two was the brighter when he assigned his"
"Altair Altair () (from Arabic """"al-ṭā'ir"""") also designated Alpha Aquilae (α Aquilae, abbreviated Alpha Aql, α Aql), is the brightest star in the constellation of Aquila and the twelfth brightest star in the night sky. It is currently in the G-cloud—a nearby interstellar cloud, which is an accumulation of gas and dust. Altair is an A-type main sequence star with an apparent visual magnitude of 0.77 and is one of the vertices of the asterism known as the Summer Triangle (the other two vertices are marked by Deneb and Vega). It is 16.7 light-years (5.13 parsecs) from the Sun and"
"stars, though several lie across the boundary in Ursa Major. Overall, there are 97 stars within the constellation's borders brighter than or equal to apparent magnitude 6.5. The brightest star in this constellation is Alpha Lyncis, with an apparent (visual) magnitude of 3.14. It is an orange giant of spectral type K7III located 203 ± 2 light-years distant from Earth. Around twice as massive as the Sun, it has exhausted the hydrogen at its core and has evolved away from the main sequence. The star has swollen to about 55 times the Sun's radius and is emitting roughly 673 times"
"star he designated in the neighbouring constellation Crater—31 Crateris—lay within Corvus once the constellation boundaries were established in 1930. Within the constellation's borders, there are 29 stars brighter than or equal to apparent magnitude 6.5. Four principal stars, Delta, Gamma, Epsilon, and Beta Corvi, form a quadrilateral asterism known as ""the ""Spica's Spanker"" or ""the Sail"". Although none of the stars are particularly bright, they lie in a dim area of the sky, rendering the asterism easy to distinguish in the night sky. Gamma and Delta serve as pointers toward Spica. Also called Gienah, Gamma is the brightest star in"
"designation. It bore the traditional name ""Anser"", derived from when the constellation had the name ""Vulpecula cum Ansere"" 'the little fox with the goose'. In 2016, the IAU organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN approved the name ""Anser"" for this star on 30 June 2017 and it is now so included in the List of IAU-approved Star Names. Alpha Vulpeculae Alpha Vulpeculae (α Vulpeculae, abbreviated Alf Vul, α Vul), also named Anser, is the brightest star in the constellation of Vulpecula. It is approximately 297 light-years from Earth."
"bright stars. These include Sirius (Alpha Canis Majoris), the brightest star in the night sky, as well as three other stars above magnitude 2.0. Furthermore, two other stars are thought to have previously outshone all others in the night sky—Adhara (Epsilon Canis Majoris) shone at -3.99 around 4.7 million years ago, and Mirzam (Beta Canis Majoris) peaked at −3.65 around 4.42 million years ago. Another, NR Canis Majoris, will be brightest at magnitude −0.88 in about 2.87 million years' time. The German cartographer Johann Bayer used the Greek letters Alpha through Omicron to label the most prominent stars in the"
"Moravveji and colleagues calculate a luminosity for Rigel A of 120,000 times that of the Sun. Its surface temperature is around 12,100 K. The interferometer-measured angular diameter of this star, after correction for limb darkening, is . At its estimated distance, this yields a size of about 78.9 times the radius of the Sun. Norbert Przybilla and colleagues used atmospheric modelling in 2006 to come up with a distance of . They calculated it to be around 218,000 times as luminous as the Sun, and have around 21 ± 3 solar masses and 109 ± 12 times its radius. The"
"the constellation, as adopted by the International Astronomical Union in 1922, is 'Cir'. Circinus is a faint constellation, with only one star brighter than fourth magnitude. Alpha Circini, a white main sequence star with an apparent magnitude of 3.19, is 54 light-years away and 4° south of Alpha Centauri. Not only the brightest star in the constellation, it is also the brightest example of a rapidly oscillating Ap (RoAp) star in the night sky. It has the unusual spectral type A7 Vp SrCrE, showing increased emissions of strontium, chromium and europium. Stars of this type have oddly localised magnetic fields"
"the Sun making it one of the most luminous stars in the Milky Way. Pistol Nebula The Pistol Nebula is located in the constellation Sagittarius. It surrounds one of the most luminous stars known, the Pistol Star. Both are located 25,000 light years away from Earth in the Quintuplet cluster, near the center of the Milky Way galaxy. The nebula contains approximately 9.3 solar masses worth of ionized gas that was ejected by the star several thousand years ago. The nebula was named in the 1980s for its shape as seen in low resolution images that were available at the"