"in fact the supernova known as Tycho's Supernova. Within the constellation's borders, there are 157 stars brighter than or equal to apparent magnitude 6.5. The five brightest stars of Cassiopeia – Alpha, Beta, Gamma, Delta, and Epsilon Cassiopeiae – form the characteristic W-shaped asterism. All five are prominent naked eye stars, three are noticeably variable, and a fourth is a suspected low amplitude variable. The asterism is oriented as a W when below Polaris during northern spring and summer nights. In northern winter, and when seen from southern latitudes, it is ""above"" Polaris (i.e. closer to the zenith) and the"
"Five Chariots Five Chariots (五車, pinyin: Wǔ Ju) is a constellation in Chinese astronomy. A five-star Chinese constellation equivalent to Auriga minus δ Aur (Delta Aurigae). Also known in Japanese as Gosha (Five Chariots; 五車). The Five Chariots otherwise known as Auriga is a constellation that borders Taurus. The constellation is named as such due to the five main stars, representing the five celestial emperors. The constellation appears within the region of the sky dominated by the White Tiger of the West. Within the region of the White Tiger of the West there are seven mansions, the Five Chariots resides"
"star, three Wolf-Rayet stars, two of them carbon-rich, and other young, massive stars. The closest complex, formed by ""G10.2-0.3"" and ""G10.6-0.4"", includes a very young (0.6 Myr) star cluster with at least four O stars and five massive YSOs. Westerhout 31 Westerhout 31, also known as W31, is a complex of star formation regions of the Milky Way located in the constellation of Sagittarius. As happens with other similar star-forming regions, Westerhout 31's location in the Milky Way obscures it so much due to the interstellar dust located between it and the Solar System that it cannot be studied with"
"of the class of stars that came to be called Wolf-Rayet stars (WR stars) after Charles Wolf and Georges Rayet who discovered their unusual appearance. It is a member of the nitrogen sequence of WR stars, while the other two (WR 135 and WR 137) are both members of the carbon sequence that also have OB companions. WR 134 has a spectrum with N and N emission between two and five times stronger than N, leading to the assignment of a WN6 spectral type. The spectrum also shows strong He emission and weaker lines of He and C. WR 134"
"Lacerta Lacerta is one of the 88 modern constellations defined by the International Astronomical Union. Its name is Latin for lizard. A small, faint constellation, it was defined in 1687 by the astronomer Johannes Hevelius. Its brightest stars form a ""W"" shape similar to that of Cassiopeia, and it is thus sometimes referred to as 'Little Cassiopeia'. It is located between Cygnus, Cassiopeia and Andromeda on the northern celestial sphere. The northern part lies on the Milky Way. Lacerta is typical of Milky Way constellations: no bright galaxies, nor globular clusters, but instead open clusters, for example NGC 7243, the"
"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"
"W appears inverted. Alpha Cassiopeiae, traditionally called Schedar (from the Arabic ""Al Sadr"", ""the breast""), is a multiple star. The primary is an orange-hued giant of magnitude 2.2, 228 ± 2 light-years from Earth. With a luminosity of around 771 times that of the Sun, it has swollen and cooled after exhausting its core hydrogen over its 100 to 200 million-year lifespan, spending much of it as a blue-white B-type main-sequence star. The brightest companion is a magnitude 8.9 yellow dwarf widely separated from the primary, while two other companions are closer and magnitudes 13 and 14 respectively. Beta Cassiopeiae,"
"5.0. Overall, there are 22 stars within the constellation's borders brighter than or equal to apparent magnitude 6.5. The Large Magellanic Cloud lies partially within Mensa's boundaries, although most of it lies in neighbouring Dorado. It is a satellite galaxy of the Milky Way, located at a distance of 163,000 light-years. Among its stars within Mensa are W Mensae, an unusual yellow-white supergiant that belongs to a rare class of star known as a R Coronae Borealis variable, HD 268835, a blue hypergiant that is girded by a vast circumstellar disk of dust, and R71, a luminous blue variable star"
"WR 9 WR 9 is a spectroscopic binary in the constellation Cygnus consisting of a Wolf-Rayet star and a class O star. It is around 4,800 light years away. WR 9 is a binary with two components in a circular 14 day orbit. The Wolf-Rayet component is often identified as the primary because it dominates the spectrum with its broad emission lines, although it is less massive, less luminous, and less visually bright than its companion. The companion is an approximately O7 star. The spectrum is dominated by broad emission lines, those of C being the strongest, followed by He."
"from every location on Earth except within the Antarctic circle. The red giant Gamma Sagittae is the constellation's brightest star, with an apparent magnitude of 3.47. Two star systems have been found to have planets. The Greeks who may have originally identified this constellation called it ""Oistos"". The Romans named it Sagitta. Sagitta's shape is reminiscent of an arrow, and many cultures have interpreted it thus, among them the Persians, Hebrews, Greeks and Romans. The Arabs called it ""as-Sahm"", a name that was transferred ""Sham"" and now refers to Alpha Sagittae only. In ancient Greece, Sagitta was regarded as the"
"W Sagittarii W Sagittarii (W Sgr, Gamma-1 Sagittarii (γ¹ Sgr)) is a multiple star system star in the constellation Sagittarius, and a Cepheid variable star. W Sagittarii is an optical line-of-sight companion nearly a degree from the much brighter γ Sgr (Al Nasl) which marks the nozzle or spout of the teapot asterism. W Sgr is listed as component A of a multiple star system catalogued as ADS 11029 and WDS J18050-2935. Components B and C are at 33"" and 46"" respectively and both are 13th magnitude. They are purely optical companions, not physically associated with W Sgr. Component A,"
"WR 104 WR 104 is a triple star system located about from Earth. The primary star is a Wolf-Rayet star, abbreviated as WR, with a B0.5 main sequence star in close orbit and another more distant fainter companion. The WR star is surrounded by a distinctive spiral Wolf–Rayet nebula, often referred to as a pinwheel nebula. The rotational axis of the binary system, and likely of the two closest stars, is directed approximately towards Earth. Within the next few hundred thousand years, the Wolf-Rayet star is predicted to probably become a core-collapse-supernova with a small chance of producing a long"
"Wolf-Rayet star and a B0.5 main sequence star. The WR star is visually 0.3 magnitudes fainter than the main sequence star, although the WR star is typically considered the primary as it dominates the appearance of the spectrum and is more luminous. The two are in a nearly circular orbit separated by about 2 AU, which would be about one milli-arcsecond at the assumed distance. The two stars orbit every 241.5 days with a small inclination (i.e. nearly face-on). The visually resolved companion is 1.5 magnitudes fainter than the combined spectroscopic pair and almost one arc-second away. It is thought"
"V, which makes it an F-type main sequence star. The pair is about 63 million years old. In Chinese, (), meaning ""Legs (asterism)"", refers to an asterism consisting of ν Andromedae, η Andromedae, 65 Piscium, ζ Andromedae, ε Andromedae, δ Andromedae, π Andromedae, μ Andromedae, β Andromedae, σ Piscium, τ Piscium, 91 Piscium, υ Piscium, φ Piscium, χ Piscium and ψ¹ Piscium. Consequently, ν Andromedae itself is known as (, .) Nu Andromedae Nu Andromedae (Nu And, ν Andromedae, ν And) is a binary star in the constellation Andromeda. The system has an apparent visual magnitude of 4.5, which is"
"the International Astronomical Union organized a Working Group on Star Names (WGSN) to 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 ""Menkalinan"" for this star. It is known as 五車三 (the Third Star of the Five Chariots) in traditional Chinese astronomy. Beta Aurigae is a binary star system, although the light that the star system releases forges the appearance of a single star in the night sky. The two brightest components are metallic-lined subgiant stars belonging to the"
"to the south, touching on Telescopium to the southwest. The recommended three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is 'Mic'. The official constellation boundaries, as set by Eugène Delporte in 1930, are defined by a polygon of four segments (""illustrated in infobox""). In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between −27.45° and −45.09°. The whole constellation is visible to observers south of latitude 45°N. Given that its brightest stars are of fifth magnitude, the constellation is invisible to the"
"Lynx (constellation) Lynx is a constellation named after the animal, usually observed in the northern sky. The constellation was introduced in the late 17th century by Johannes Hevelius. It is a faint constellation, with its brightest stars forming a zigzag line. The orange giant Alpha Lyncis is the brightest star in the constellation, and the semiregular variable star Y Lyncis is a target for amateur astronomers. Six star systems have been found to contain planets. Those of 6 Lyncis and HD 75898 were discovered by the Doppler method; those of XO-2, XO-4, XO-5 and WASP-13 were observed as they passed"
"W Mensae W Mensae (W Men) is an unusual yellow supergiant star in the Large Magellanic Cloud in the southern constellation Mensa. It is an R Coronae Borealis variable and periodically decreases in brightness by several magnitudes. W Men is very distant, being located in the neighboring galaxy Large Magellanic Cloud, where it lies on the southern metal-deficient edge. Despite its high luminosity, the star has a maximum apparent brightness of +13.8, too dim to be visible in a small telescope. Its radius has been calculated to be 61 times that of the Sun. The variability of W Men was"
"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"
"Westerhout 31 Westerhout 31, also known as W31, is a complex of star formation regions of the Milky Way located in the constellation of Sagittarius. As happens with other similar star-forming regions, Westerhout 31's location in the Milky Way obscures it so much due to the interstellar dust located between it and the Solar System that it cannot be studied with optical telescopes and for its observation infrared telescopes such as Spitzer, radiotelescopes, or instruments able to detect X Rays and Gamma rays are needed. Westerhout 31 seems to be actually formed of several star-forming regions at very different distances"
"the Wolf-Rayet star would have to undergo an extraordinary string of successive events: WR 104 WR 104 is a triple star system located about from Earth. The primary star is a Wolf-Rayet star, abbreviated as WR, with a B0.5 main sequence star in close orbit and another more distant fainter companion. The WR star is surrounded by a distinctive spiral Wolf–Rayet nebula, often referred to as a pinwheel nebula. The rotational axis of the binary system, and likely of the two closest stars, is directed approximately towards Earth. Within the next few hundred thousand years, the Wolf-Rayet star is predicted"
"other WN stars. They were previously referred to as WNL stars, although there are late-type WN stars without hydrogen as well as WR stars with hydrogen as early as WN5. Wolf–Rayet stars were named on the basis of the strong broad emission lines in their spectra, identified with helium, nitrogen, carbon, silicon, and oxygen, but with hydrogen lines usually weak or absent. The first system of classification split these into stars with dominant lines of ionised nitrogen (N, N, and N) and those with dominant lines of ionised carbon (C and C) and sometimes oxygen (O - O), referred to"
"W Aquilae W Aquilae (W Aql / SAO 143184 / GC 2525) is a variable star in the constellation of Aquila. Its distance from the solar system is estimated between 1,100 and 7,502 light-years. W Aquilae is an S-type star with a spectral type of S3e to S6e, a red giant similar to M-type stars, but in which the dominant spectrum oxides are formed by metals of the fifth period of the periodic table. W Aquilae is also rich in the element technetium. Another feature of this class of stars is the stellar mass loss, in the case of W"
"branch, and started helium fusion in its core. τ Sagittarii is the closest constellational star (a star that is part of the traditional outline of a constellation) to the origin of the 1977 Wow! signal. \end{align}</math></ref> Tau Sagittarii Tau Sagittarii (Tau Sgr, τ Sagittarii, τ Sgr) is a star in the southern zodiac constellation of Sagittarius. With an apparent visual magnitude of +3.3, this is one of the brighter members of the constellation. The distance of this star from Earth is roughly , based upon parallax measurements. This is a spectral type K1 giant star with about . The stellar"
"KW Sagittarii KW Sagittarii is a red supergiant, located approximately 2,400 parsecs away from our Sun in the direction of the constellation Sagittarius. It has a size over making it one of the largest known stars. If placed at the center of the Solar System, the star's surface would engulf Mars. The distance of 2,400 parsecs is based on the assumption of membership on the Sagittarius OB5 association. The parallax derived from the Hipparcos mission is negative so doesn't give much information about the distance except that it is likely to be large. Levesque calculate that the star has a"
"of the constellation is Praesepe (Messier 44), one of the closest open clusters to Earth and a popular target for amateur astronomers. Cancer is a medium-sized constellation that is bordered by Gemini to the west, Lynx to the north, Leo Minor to the northeast, Leo to the east, Hydra to the south, and Canis Minor to the southwest. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is 'Cnc'. The official constellation boundaries, as set by Eugène Delporte in 1930, are defined by a polygon of 10 sides (""illustrated in infobox""). In the equatorial"
"triple star system. The companion θ Muscae B is not part of the triple system but an optical double which happens to be along the same line of sight. It is a luminous O class giant star. It is suspected of itself being a spectroscopic binary with the companion being much fainter. The triple star θ Muscae A is composed of two parts: a spectroscopic binary system composed of the Wolf–Rayet star (spectral type: WC5 or 6) and an O-type main-sequence star (spectral type: O6 or O7) that orbit each other every 19 days and a blue supergiant (spectral type:"
"sequence O, B, A, F, G, K and M. (A popular mnemonic for memorizing this sequence of stellar classes is ""Oh Be A Fine Girl/Guy, Kiss Me"".) The luminosity class ranged from I to V, in order of decreasing luminosity. Stars of luminosity class V belonged to the main sequence. In April 2018, astronomers reported the detection of the most distant ""ordinary"" (i.e., main sequence) star, named Icarus (formally, MACS J1149 Lensed Star 1), at 9 billion light-years away from Earth. When a protostar is formed from the collapse of a giant molecular cloud of gas and dust in the"
"sequence star, respectively. The tertiary and fifth component, Zeta Piscium C, is a magnitude 12.2 star at an angular separation 1.0 arc seconds from component B. Zeta Piscium Zeta Piscium (ζ Piscium, abbreviated Zet Psc, ζ Psc) is a quintuple star system in the zodiac constellation of Pisces. Based upon parallax measurements obtained during the Hipparcos mission, it is located roughly distant from the Sun. The system is composed of a binary star (designated Zeta Piscium A) and a triple star system (BC), the latter consisting of a spectroscopic binary (B) and a single star (C). A's two components are"
"larger, and some of the most luminous stars known. They have been detected as early as WN5h in the Magellanic clouds. The nitrogen seen in the spectrum of WNh stars is still the product of CNO cycle fusion in the core, but it appears at the surface of the most massive stars due to rotational and convectional mixing while still in the core hydrogen burning phase, rather than after the outer envelope is lost during core helium fusion. Some Wolf–Rayet stars of the carbon sequence (""WC""), especially those belonging to the latest types, are noticeable due to their production of"
"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."
"separated by an angle of 27 arcseconds and have apparent magnitudes of 4.4 and 4.5 respectively. They can be separated in small telescopes. A third star, Beta Tucanae, is separated by 10 arcminutes from the two, and able to be seen as a separate star with the unaided eye. Each star is itself a binary star, making six in total. Lying in the southwestern corner of the constellation around 251 light-years away from Earth, Delta Tucanae consists of a blue-white primary contrasting with a yellowish companion. Delta Tucanae A is a main sequence star of spectral type B9.5V and an"
"in front of the host star. Within the constellation's borders lie NGC 2419, an unusually remote globular cluster; the galaxy NGC 2770, which has hosted three recent Type Ib supernovae; the distant quasar APM 08279+5255, whose light is magnified and split into multiple images by the gravitational lensing effect of a foreground galaxy; and the Lynx Supercluster, which was the most distant supercluster known at the time of its discovery in 1999. Polish astronomer Johannes Hevelius formed the constellation in 1687 from 19 faint stars between the constellations Ursa Major and Auriga that earlier had been part of the obsolete"