Object type | Semiregular variable star |
---|---|
Other designations | DO 42253, FK5 6018, GCRV 27213, GSC 04654-00911, HD 217158, HIC 112882, HIP 112882, IRAS 22526+8446, 2MASS J22513374+8502469, PPM 4030, RAFGL 2988, SAO 3809, AG+84 497, BD+84 516, Gaia DR2 2300884800184802816, AR Cep, AAVSO 2253+84, GC 31962, TYC 4654-911-1, TIC 461522596, Gaia DR3 2300884800185315712 |
Observation data (Epoch J2000) | |
Constellation | Cepheus |
22h 51m 33.68 | |
Declination | +85° 02` 46.9 |
Distance | ~1,114 ly |
In visual light (V) | |
+7.3 | |
Temperature | 2,400 - 3,700 K |
AR Cephei (AR Cep) is a variable star in the constellation Cepheus. It is classified as a semiregular star, [1] [2] and has a maximum apparent magnitude of +7.32.
AR Cephei is located approximately 1,114 light-years (350 parsecs) from the Solar System, and has a radial velocity of -14.58000 ± 0.48 km/s, meaning that it is moving toward the Sun at ~14 kilometers every second.[ citation needed ]
Aernout de Sitter discovered the star in 1933. [4] [5] It was given its variable star designation, AR Cephei, in 1939. [5]
Cepheus is a constellation in the deep northern sky, named after Cepheus, a king of Aethiopia in Greek mythology. It is one of the 48 constellations listed by the second century astronomer Ptolemy, and it remains one of the 88 constellations in the modern times.
Gamma Cephei is a binary star system approximately 45 light-years away in the northern constellation of Cepheus. The primary is a stellar class K1 orange giant or subgiant star; it has a red dwarf companion. An exoplanet has been confirmed to be orbiting the primary.
Alpha Cephei, officially named Alderamin, is a second magnitude star in the constellation of Cepheus near the northern pole. The star is relatively close to Earth at 49 light years (ly) and drifting closer with a heliocentric radial velocity of about −16 km/s.
Mu Cephei, also known as Herschel's Garnet Star, Erakis, or HD 206936, is a red supergiant or hypergiant star in the constellation Cepheus. It appears garnet red and is located at the edge of the IC 1396 nebula. It is a 4th magnitude star easily visible to the naked eye under good observing conditions. Since 1943, the spectrum of this star has served as a spectral standard by which other stars are classified.
Delta Cephei is a quadruple star system located approximately 887 light-years away in the northern constellation of Cepheus, the King. At this distance, the visual magnitude of the star is diminished by 0.23 as a result of extinction caused by gas and dust along the line of sight. It is the prototype of the Cepheid variable stars that undergo periodic changes in luminosity.
Beta Cephei is a triple star system of the third magnitude in the constellation of Cepheus. Based on parallax measurements obtained during the Hipparcos mission, it is approximately 690 light-years distant from the Sun. It is the prototype of the Beta Cephei variable stars.
VV Cephei, also known as HD 208816, is an eclipsing binary star system located in the constellation Cepheus. It is both a B[e] star and shell star. As a 5th magnitude star, it is visible to the naked eye under good observing conditions.
V354 Cephei is a red supergiant star located within the Milky Way. It is an irregular variable located over 13,000 light-years away from the Sun. It has an estimated radius of 1,139 solar radii. If it were placed in the center of the Solar System, it would extend to between the orbits of Mars and Jupiter.
Nu Cephei is a class A2, fourth-magnitude blue supergiant star in the constellation Cepheus, visible to the naked eye. It is a white pulsating α Cygni variable star located about 4,700 light-years from Earth.
W Cephei is a spectroscopic binary and variable star located in the constellation Cepheus. It is thought to be a member of the Cep OB1 stellar association at about 8,000 light years. The supergiant primary star is one of the largest known stars and as well as one of the most luminous red supergiants.
MY Cephei is a red supergiant located in open cluster NGC 7419 in the constellation of Cepheus. It is a semiregular variable star with a maximum brightness of magnitude 14.4 and a minimum of magnitude 15.5.
T Cephei is a Mira variable star in the constellation Cepheus. Located approximately 600 light-years distant, it varies between magnitudes 5.2 and 11.3 over a period of around 388 days. When it is near its maximum brightness, it is faintly visible to the naked eye under good observing conditions.
Z Apodis (Z Aps) is a variable star in the constellation of Apus. It has an apparent visual magnitude which varies between 10.8 and 12.8, over a period of 39.37 days. Although described in the General Catalogue of Variable Stars as a cataclysmic variable star, it appears that it is a pulsating variable star, and has been classed as an RV Tauri variable star, type RVa. Other sources classify it is a type II Cepheid.
RT Normae is an R Coronae Borealis type variable star in the constellation Norma. It has a baseline magnitude of 9.8, dropping down to 14.7 at its minima.
RZ Normae is an R Coronae Borealis type variable star in the constellation Norma. It has a baseline magnitude of 10.2, dropping down to dimmer than 16.2 at its minima. It was discovered by the astronomer Sergei Gaposchkin in 1952.
V1936 Aquilae is a blue supergiant and candidate Luminous blue variable located in the nebula Westerhout 51, in the constellation Aquila, about 20,000 light years away. The star was originally identified as a massive star in 2000, and was thought to be an O-type supergiant. However, subsequent analyses have shown it to be not O but B-type, as well as being possibly an LBV. The star was shown to be a variable star by Luboš Kohoutek and R. Wehmeyer in 2004.
WY Geminorum is a binary star system in the northern constellation of Gemini, abbreviated WY Gem. It has an apparent visual magnitude that ranges from 7.26 down to 7.51, which is too faint to be readily viewed with the naked eye. This system is located at a distance of approximately 6,300 light years from the Sun based on parallax measurements, and is receding with a radial velocity of 19.5 km/s.
ST Cephei is a large variable star located in the constellation Cepheus. It has a mean apparent magnitude of +7.84, and a solar radius of 1,218.
S Cephei, also designated as HD 206362, is a carbon star and Mira-type variable in the constellation Cepheus. Based on the measurement of its annual parallax by the Gaia satellite, the star is approximately ∼1,590 ly away from Earth.
WY Velorum, also known as HD 81137, is a binary system between a variable red supergiant (RSG) and a blue giant companion in the constellation of Vela. It is located approximately 1,900 parsecs distant. Its apparent magnitude slowly varies over the course of years between 8.84 and 10.22. As such, it has been described as an irregular variable, though a rough 550-day period and a more uncertain 370-day period have been detected. The primary star is among the largest stars discovered to date, with an estimated radius of 1,157 R☉. If it replaced the Sun, its surface would reach past Jupiter's orbit.