Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cygnus |
Right ascension | 21h 01m 09.20684s [1] |
Declination | +50° 21′ 44.8033″ [1] |
Apparent magnitude (V) | 11.99 [2] |
Characteristics | |
Spectral type | G7-K0IV [3] |
Astrometry | |
Proper motion (μ) | RA: 0.980 [1] mas/yr Dec.: −3.783 [1] mas/yr |
Parallax (π) | 1.6760 ± 0.0237 mas [1] |
Distance | 1,950 ± 30 ly (597 ± 8 pc) |
Details [3] | |
Mass | 2.8 M☉ |
Radius | 5 R☉ |
Temperature | 5200 K |
Other designations | |
Database references | |
SIMBAD | data |
V1331 Cygni (also known as V1331 Cyg) is a young star in the constellation Cygnus. V1331 Cyg is located in the dark nebula LDN 981. [4]
V1331 Cygni is most noted for having an arc-like reflection nebula surrounding it. This circumstellar disc is a great birthplace for young stars, which form in the cloud. [5] V1331 Cygni is heavily obscured by dust, so the properties of the central star are hard to deduce; however, it is estimated to have a radius five times that of the Sun and a mass of 2.8 M☉. [3]
The General Catalog of Variable Stars classifies V1331 Cygni as an "INST" type variable, meaning a T Tauri star which shows rapid light variations. [7] [8] Its visual band brightness varies from magnitude 13.08 to 10.58. [7] It is sometimes classified as a pre-FUOR star. [9] A semi-regular period of ~449 days has been reported. [9] Unlike many T Tauri stars, the mean brightness of V1331 Cygni remains nearly constant over long time periods. [10] [6]
V1500 Cygni or Nova Cygni 1975 was a bright nova occurring in 1975 in the constellation Cygnus. It had the second highest intrinsic brightness of any nova of the 20th century, exceeded only by CP Puppis in 1942.
Merope, designated 23 Tauri, is a star in the constellation of Taurus and a member of the Pleiades star cluster. It is approximately 440 light-years (135 pc) away.
RV Tauri is a star in the constellation Taurus. It is a yellow supergiant and is the prototype of a class of pulsating variables known as RV Tauri variables. It is a post-AGB star and a spectroscopic binary about 4,700 light years away.
AE Aurigae is a runaway star in the constellation Auriga; it lights the Flaming Star Nebula.
HD 96919, also known by its Bayer designation of z2 Carinae and the variable star designation of V371 Carinae, is a blue supergiant star in the constellation Carina. It lies near the Carina Nebula and at a comparable distance.
32 Cygni is a binary star system in the Cygnus constellation. It is a 4th magnitude star, which can be seen with the naked eye under suitably dark skies. Parallax measurements give an estimated distance of 1,000 light-years (307 parsecs) from the Earth. However, Schröder et al. (2007) suggest the actual value, after correcting for Malmquist bias, may be closer to 1,174 light-years (360 parsecs). Although it is a spectrsocopic binary with components that cannot be separated visually, it has two entries in the Henry Draper Catalogue, with identical magnitudes and positions, but showing the spectral types of the two components.
V1057 Cygni is a suspected binary star system in the northern constellation of Cygnus. It is a variable star of the FU Orionis-type, and was the second FU Orionis-type variable to be discovered. The system is located at a distance of approximately 3,000 light years from the Sun, in the North America Nebula. It has an apparent visual magnitude of around 12.4.
SS Cygni is a variable star in the northern constellation Cygnus. It was discovered in 1896 by Louisa D. Wells, a computer working under Edward Pickering at Harvard College Observatory. It is the prototype of the subclass of dwarf novae that show only normal eruptions. It typically rises from 12th magnitude to 8th magnitude for 1–2 days every 7 or 8 weeks. The northerly declination of SS Cygni makes the star almost circumpolar from European and North American latitudes, allowing a large proportion of the world's amateur astronomers to monitor its behavior. Furthermore, since the star lies against the rich backdrop of the Milky Way band, the telescope field of view around SS Cygni contains an abundance of useful brightness comparison stars.
HD 168607 is a blue hypergiant and luminous blue variable (LBV) star located in the constellation of Sagittarius, easy to see with amateur telescopes. It forms a pair with HD 168625, also a blue hypergiant and possible luminous blue variable, that can be seen at the south-east of M17, the Omega Nebula.
Iota2 Cygni, Latinized from ι2 Cygni and often simply called ι Cygni, is a single star in the constellation Cygnus. It is visible to the naked eye as a white-hued point of light with an apparent visual magnitude of 3.76. Located around 121.3 light-years distant from the Sun based on parallax, it is drifting closer with a radial velocity of −19.5 km/s and is expected to come to within 92 light-years in around 783,000 years.
55 Cygni is a blue supergiant star in the constellation Cygnus. It is thought to be a member of the Cygnus OB7 stellar association at about 2,700 light years.
29 Cygni is a single star in the northern constellation of Cygnus. It is dimly visible to the naked eye as a white-hued star with an apparent visual magnitude of 4.93. The distance to 29 Cyg, as estimated from an annual parallax shift of 24.5 mas, is 133 light years. The star is moving closer to the Earth with a heliocentric radial velocity of −17 km/s. It is a member of the 30–50 million year old Argus Association of co-moving stars.
R Geminorum is a Mira variable and technetium star in the constellation Gemini. It is located approximately 850 parsecs (2,800 ly) away.
W Cygni is a semi-regular variable star in the constellation Cygnus, located 570 light-years from Earth. It lies less than half a degree southeast of ρ Cygni. W Cygni is, at times, a naked eye star but it was not given a Bayer or Flamsteed designation. It has been proposed as a binary star system with a hotter main sequence companion, but this has not been confirmed.
R Cygni is a variable star of the Mira type in the constellation Cygnus, less than 4' from θ Cygni. This is a red giant star on the asymptotic giant branch located around 2,200 light years away. It is an S-type star ranging between spectral types S2.5,9e to S6,9e(Tc).
HD 65750, also known as V341 Carinae is a bright red giant star in the constellation Carina. It is surrounded by a prominent reflection nebula, known as IC 2220, nicknamed the Toby Jug Nebula.
WR 31a, commonly referred to as Hen 3-519, is a Wolf–Rayet (WR) star in the southern constellation of Carina that is surrounded by an expanding Wolf–Rayet nebula. It is not a classical old stripped-envelope WR star, but a young massive star which still has some hydrogen left in its atmosphere.
S Cassiopeiae is a Mira variable and S-type star in the constellation Cassiopeia. It is an unusually cool star, rapidly losing mass and surrounded by dense gas and dust producing masers.
SX Centauri is a variable star in the constellation Centaurus. An RV Tauri variable, its light curve alternates between deep and shallow minima, varying its apparent magnitude from 9.1 to 12.4. From the period-luminosity relationship, it is estimated to be around 1.6 kpc from Earth. Gaia Data Release 2 gives a parallax of 0.2175 mas, corresponding to distance of about 4,600 pc.
CH Cygni is a red giant, variable, symbiotic binary in the constellation Cygnus. It is the nearest symbiotic star to Earth, and one of the brightest, making it an ideal candidate for study.