"average 2.69 AU from the other two stars. AG Persei is another Algol variable in Perseus, whose primary component is a B-type main sequence star with an apparent magnitude of 6.69. Phi Persei is a double star, although the two components do not eclipse each other. The primary star is a Be star of spectral type B0.5, possibly a giant star, and the secondary companion is likely a stellar remnant. The secondary has a similar spectral type to O-type subdwarfs. With the historical name Mirfak (Arabic for ""elbow"") or Algenib, Alpha Persei is the brightest star of this constellation with"
"Montanari. The name Algol means ""demon star"" (from ""al-ghūl""), which was probably given due to its peculiar behavior. Another visible ternary is Alpha Centauri, in the southern constellation of Centaurus, which contains the fourth-brightest star in the night sky, with an apparent visual magnitude of −0.01. This system also underscores the fact that binaries need not be discounted in the search for habitable planets. Alpha Centauri A and B have an 11 AU distance at closest approach, and both should have stable habitable zones. There are also examples of systems beyond ternaries: Castor is a sextuple star system, which is"
"(see ""The Stars My Destination"" by Alfred Bester, Demon Princes by Jack Vance, and Star Trek below). Rigel is the brightest star in the constellation Orion and the sixth brightest star in the sky, with an apparent magnitude of 0.18. Although it has the Bayer designation ""Beta,"" it is almost always brighter than Alpha Orionis (Betelgeuse). Whereas the latter star represents the right shoulder of the Hunter, Rigel represents his left foot. It is the first star counterclockwise from Sirius in the Winter Hexagon, and is followed in turn by Aldebaran. The star's name is a contraction of ""Riǧl Ǧawza"
"Orion (constellation) Orion is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous and recognizable constellations in the night sky. It was named after Orion, a hunter in Greek mythology. Its brightest stars are Rigel (Beta Orionis) and Betelgeuse (Alpha Orionis), a blue-white and a red supergiant, respectively. The earliest depiction that has been linked to the constellation of Orion is a prehistoric (Aurignacian) mammoth ivory carving found in a cave in the Ach valley in West Germany in 1979. Archaeologists have estimated it to have been fashioned approximately"
"size. It appears prominently in the northern sky during the Northern Hemisphere's spring. Its main asterism consists of 19 stars. The constellation's boundaries, as set by Eugène Delporte in 1930, are defined by a 26-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 ""Per"" for the constellation in 1922. Algol (from the Arabic رأس الغول ""Ra's al-Ghul"", which means ""The Demon's Head""), also known by its Bayer designation Beta Persei, is the best-known star"
"for example Betelgeuse, which is predicted to explode sometime in the next million years. Orion (constellation) Orion is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous and recognizable constellations in the night sky. It was named after Orion, a hunter in Greek mythology. Its brightest stars are Rigel (Beta Orionis) and Betelgeuse (Alpha Orionis), a blue-white and a red supergiant, respectively. The earliest depiction that has been linked to the constellation of Orion is a prehistoric (Aurignacian) mammoth ivory carving found in a cave in the Ach valley"
"attack cargo ship was named after the star. Gamma Geminorum Gamma Geminorum (γ Geminorum, abbreviated Gamma Gem, γ Gem), also named Alhena, is the third-brightest star in the constellation of Gemini. It has an apparent visual magnitude of 1.9, making it easily visible to the naked eye even in urban regions. Based upon parallax measurements with the Hipparcos satellite, it is located at a distance of roughly from the Sun. Alhena is an evolving star that is exhausting the supply of hydrogen at its core and has entered the subgiant stage. The spectrum matches a stellar classification of A0 IV."
"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."
"17th century English astrologer William Lilly regarded any planet to be afflicted when within five degrees of conjunction. As of 1986 its celestial longitude was 25 Tau. 55'48. Algol is also one of the 15 Behenian stars, associated with the diamond and hellebore, and marked with the kabbalistic sign: Gienah (gamma Corvi) is supposed to have a similar effect to Mars and Saturn, tending to promote greed and craftiness. It was one of the medieval Behenian stars, associated with onyx, burdock, and a crow-like kabbalistic symbol . In this context it is sometimes referred to as Ala Corvi, ""the wing"
"AFGL 2298 AFGL 2298, also known as IRAS 18576+0341, is a luminous blue variable star (LBV) located in the constellation Aquila, very close to the galactic plane. Its distance is not well known; it may be anywhere between and light years (7,000 to 13,000 parsecs) away from the Earth. Despite being extremely luminous, it is extremely reddened by interstellar extinction, so its apparent magnitude is brighter for longer-wavelength passbands; in fact, in visual wavelengths it is completely undetectable. AFGL 2298 has an absolute bolometric magnitude of −11.25, making it one of the most luminous stars known. Indeed, many of the"
"Geminiano Montanari Geminiano Montanari (1 June 1633 – 13 October 1687) was an Italian astronomer, lens-maker, and proponent of the experimental approach to science. He is best known for his observation, made around 1667, that the second-brightest star (called Algol as derived from its name in Arabic) in the constellation of Perseus varied in brightness. It is likely that others had observed this effect before, but Montanari was the first named astronomer to record it. The star's names in Arabic, Hebrew and other languages, all of which have a meaning of ""ghoul"" or ""demon"", imply that its unusual behaviour had"
"Gamma Geminorum Gamma Geminorum (γ Geminorum, abbreviated Gamma Gem, γ Gem), also named Alhena, is the third-brightest star in the constellation of Gemini. It has an apparent visual magnitude of 1.9, making it easily visible to the naked eye even in urban regions. Based upon parallax measurements with the Hipparcos satellite, it is located at a distance of roughly from the Sun. Alhena is an evolving star that is exhausting the supply of hydrogen at its core and has entered the subgiant stage. The spectrum matches a stellar classification of A0 IV. Compared to the Sun it has 2.8 times"
"Betelgeuse. Rigel has a color index (B–V) of −0.03, meaning it appears white or slightly blue-white. Culminating at midnight on 12 December, and at 9 pm on 24 January, Rigel is most visible in winter evenings in the northern hemisphere and summer in the southern. In the southern hemisphere, Rigel is the first bright star of Orion visible as the constellation rises. In stellar navigation, Rigel is one of the most important navigation stars, since it is bright, easily located and equatorial, which means it is visible all around the world's oceans (the exception, areas within 8° of the North"
"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"
"visual companion stars, WDS 19508+0852B, C, and D. Component B is not physically close to A but merely appears close to it in the sky. 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"
"Large Telescope in 2010. The nebula was found to be fairly circular, and the properties of the dust appeared to be constant throughout the entire nebula. AFGL 2298 AFGL 2298, also known as IRAS 18576+0341, is a luminous blue variable star (LBV) located in the constellation Aquila, very close to the galactic plane. Its distance is not well known; it may be anywhere between and light years (7,000 to 13,000 parsecs) away from the Earth. Despite being extremely luminous, it is extremely reddened by interstellar extinction, so its apparent magnitude is brighter for longer-wavelength passbands; in fact, in visual wavelengths"
"11th millennia, when it will be visible as far north as Germany and southern England. Achernar Achernar is the name of the primary (or 'A') component of the binary system designated Alpha Eridani (α Eridani, abbreviated Alpha Eri, α Eri), which is the brightest 'star' or point of light in, and lying at the southern tip of, the constellation of Eridanus, and the tenth-brightest in the night sky. The two components are designated Alpha Eridani A (the primary) and B (the secondary, also known informally as Achernar B). As determined by the Hipparcos astrometry satellite, it is approximately from the"
"Rigel Rigel (), also designated Beta Orionis (β Orionis, abbreviated Beta Ori, β Ori), is generally the seventh-brightest star in the night sky and the brightest in the constellation of Orion—though occasionally it is outshone within the constellation by the variable star Betelgeuse. With an apparent magnitude of 0.13, it is a luminous object some 863 light-years distant from Earth. Rigel as seen from Earth is actually a multiple star system of three to five stars, the primary star (Rigel A) being a blue-white supergiant which is estimated to be anywhere from 120,000 to 279,000 times as luminous as the"
"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"
"Ptolemy's time, Alpha Centauri was visible from Alexandria, Egypt, at but, due to precession, its declination is now , and it can no longer be seen at that latitude. English explorer Robert Hues brought Alpha Centauri to the attention of European observers in his 1592 work ""Tractatus de Globis"", along with Canopus and Achernar, noting:""Now, therefore, there are but three Stars of the first magnitude that I could perceive in all those parts which are never seene here in England. The first of these is that bright Star in the sterne of Argo which they call Canobus. The second [Achernar]"
"Alpha Gruis Alpha Gruis, Latinized from α Gruis, also named Alnair, is the brightest star in the southern constellation of Grus. ""α Gruis"" (Latinised to ""Alpha Gruis"") is the star's Bayer designation. (Its first depiction in a celestial atlas was in Johann Bayer's ""Uranometria"" of 1603.) It bore the traditional name ""Alnair"" or ""Al Nair"" (sometimes ""Al Na'ir"" in lists of stars used by navigators), from the Arabic ""al-nayyir"" <nowiki>[</nowiki>an-nai:r<nowiki>]</nowiki>, meaning ""the bright one"", itself derived from its Arabic name, ""al-Nayyir min Dhanab al-ḥūt (al-Janūbiyy)"", ""the Bright (star) belongs to the Tail of (the constellation of) the (Southern) Fish"". Confusingly,"
"induce changes in its radius of gyration that have been linked to recurrent orbital period variations on the order of ≈ 10 via the Applegate mechanism. Mass transfer between the components is small in the Algol system but could be a significant source of period change in other Algol-type binaries. Algol is about 92.8 light-years from the Sun, but about 7.3 million years ago it passed within 9.8 light-years of the Solar System and its apparent magnitude was about −2.5, which is considerably brighter than the star Sirius is today. Because the total mass of the Algol system is about"
"catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included ""Algol"" for this star. It is so entered on the IAU Catalog of Star Names. In Hebrew folklore, Algol was called ""Rōsh ha Sāṭān"" or ""Satan's Head"", as stated by Edmund Chilmead, who called it ""Divels head"" or ""Rosch hassatan"". A Latin name for Algol from the 16th century was ""Caput Larvae"" or ""the Spectre's Head"". Hipparchus and Pliny made this a separate, though connected, constellation. In Chinese, (), meaning"
"in Perseus. Representing the head of the Gorgon Medusa in Greek mythology, it was called Horus in Egyptian mythology and ""Rosh ha Satan"" (""Satan's Head"") in Hebrew. Located 92.8 light-years from Earth, it varies in apparent magnitude from a minimum of 3.5 to a maximum of 2.3 over a period of 2.867 days. The star system is the prototype of a group of eclipsing binary stars named Algol variables, though it has a third member to make up what is actually a triple star system. The brightest component is a blue-white main-sequence star of spectral type B8V, which is 3.5"
"A1689-zD1 A1689-zD1 is a galaxy in the Virgo constellation cluster. It was a candidate for the most distant and therefore earliest observed galaxy discovered , based on a photometric redshift. If the redshift, z~7.6, is correct, it would explain why the galaxy's faint light reaches us at infrared wavelengths. It could only be observed with Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) and the Spitzer Space Telescope's Infrared Array Camera exploiting the natural phenomenon of gravitational lensing: the galaxy cluster Abell 1689, which lies between Earth and A1689-zD1, at a distance of 2.2 billion light-years from us,"
"Betelgeuse"" by Robert R. Chase and ""Calculating God"" by Robert J. Sawyer, below). Betelgeuse is the eighth-brightest star in the night sky and second-brightest star in the constellation of Orion, outshining its neighbour Rigel (Beta Orionis) only rarely. Distinctly reddish-tinted, it is a semiregular variable star whose apparent magnitude oscillates between 0.2 and 1.2, the widest range of any first magnitude star. It marks the upper right vertex of the Winter Triangle and center of the Winter Hexagon. There is considerable controversy about the Arabic language origin of the name Betelgeuse, with some dozens of possible derivations and spellings proposed"
"in the far Southern Celestial Hemisphere means that the whole constellation is visible to observers south of latitude 26°N, and parts become circumpolar south of latitude 35°S. Pictor is a faint constellation; its three brightest stars can be seen near the prominent Canopus. Within the constellation's borders, there are 49 stars brighter than or equal to apparent magnitude 6.5. Located about 97 light-years away from Earth, Alpha Pictoris is the brightest star in the constellation; it is a white main-sequence star with an apparent magnitude of 3.3, and spectral type A8VnkA6. A rapidly spinning star with a projected rotational velocity"
"margin of error). The space velocity components of this star in the Galactic coordinate system are [""U"", ""V"", ""W""] = , , . \end{align}</math></ref> Alpha Gruis Alpha Gruis, Latinized from α Gruis, also named Alnair, is the brightest star in the southern constellation of Grus. ""α Gruis"" (Latinised to ""Alpha Gruis"") is the star's Bayer designation. (Its first depiction in a celestial atlas was in Johann Bayer's ""Uranometria"" of 1603.) It bore the traditional name ""Alnair"" or ""Al Nair"" (sometimes ""Al Na'ir"" in lists of stars used by navigators), from the Arabic ""al-nayyir"" <nowiki>[</nowiki>an-nai:r<nowiki>]</nowiki>, meaning ""the bright one"", itself derived"
"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"
"Containing 537 Named Stars"", ""Al Kalbain"" were the title for five stars : φ as ""Alkalbain I"", χ as ""Alkalbain II"", κ as ""Alkalbain III"", κ as ""Alkalbain IV"" and this star (υ) as ""Alkalbain V"". Upsilon Tauri Upsilon Tauri (υ Tauri) is a solitary, white-hued star in the zodiac constellation of Taurus, and is a member of the Hyades star cluster. It is faintly visible to the naked eye with an apparent visual magnitude of +4.28. Based upon an annual parallax shift of 21.21 mas as seen from Earth, it is located around 154 light years from the Sun."
"of the naming the Algol-class ships after bright stars, the ""Capella"" was named after Capella, the brightest star in the constellation Auriga, the sixth brightest in the night sky. Conversion began on 23 October 1982 at Pennsylvania Shipbuilding in Chester, Pennsylvania. Her cargo hold was redesigned into a series of decks connected by ramps so vehicles can be driven into and out of the cargo hold for fast loading and unloading. She was also fitted with two sets of two cranes; one set located at midship capable of lifting 35 tons, and another set located aft capable of lifting 50"
"the ship Argo Navis, before the constellation was split. The star has an apparent visual magnitude of 3.861, so is visible to the naked eye under good conditions, though light pollution may result in stars dimmer than magnitude 3 being too dim to see. It is the second brightest in its constellation, exceeded only by Alpha Pictoris, which has an apparent magnitude of 3.30. The distance to Beta Pictoris and many other stars was measured by the Hipparcos satellite. This was done by measuring its trigonometric parallax: the slight displacement in its position observed as the Earth moves around the"
"depicted Perseus holding the disembodied head of Medusa, whose asterism was named together as ""Perseus et Caput Medusae"", however, this never came into popular usage. The galactic plane of the Milky Way passes through Perseus, whose brightest star is the yellow-white supergiant Alpha Persei (also called Mirfak or Mirphak), which shines at magnitude 1.79. It and many of the surrounding stars are members of an open cluster known as the Alpha Persei Cluster. The best-known star, however, is Algol (Beta Persei), linked with ominous legends because of its variability, which is noticeable to the naked eye. Rather than being an"