V354 Cephei

Observational Data
Designation |  IRAS 22317+5838
Right ascension |  22h 33m 34.6349s[1][2]
Declination |  +58° 52′ 47.1259″[1][2]
Constellation |  Cepheus
Type of object |  Supergiant
Magnitude |  Apparent Mag: +10.42[3]
Astrometry
Distance from Earth |  9,000 ly[3]
Radial velocity |  -59.42 ± 0.28 km/s[1][2]
Proper motion |  RA: -2.816 mas/yr[1][2]
Dec: -2.510 mas/yr[1][2]
Parallax |  0.4581 ± 0.1023 mas[1][2]

V354 Cephei is a supergiant star in the constellation of Cepheus.[4] It is one of the largest stars known, thought to have a radius over 1,500 times greater than the Sun's. This would mean the star's outer layers extend significantly beyond Saturn if it replaced the Sun.[5] While it has one of the largest radii of any star known, it has a more modest mass estimated at 25 solar masses.[5] Its luminosity is estimated to be 300, times greater than Sol's. A medium sized (4.5 - 6.0 inches) telescope is required to observe the star as although large, it appears faint in the night sky.

V354 Cephei is located 9,000 light years from Earth meaning it shines with an apparent magnitude of +10.42.[3] The star is known to be a variable star with its magnitude varying by around 0.5.[6][7] The star's period is not known, it may be an irregular variable.

## See also[edit]

* RW Cephei
* Mu Cephei
* VY Canis Majoris

## References[edit]

1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 V354 Cephei. Simbad Astronomical Database. simbad.u-strasbg.fr. Retrieved on July 06, 2020.
2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Gaia Collaboration (2018). "VizieR Online Data Catalog: Gaia DR2". VizieR Online Data Catalog I/345: I/345. Bibcode: 2018yCat.1345....0G. arXiv:0708.1752
3. ↑ 3.0 3.1 3.2 V354 Cephei. universeguide. Retrieved on July 06, 2020.
4. ↑ Janet Mason (Janurary 16, 2020). The largest stars in the Universe (that we’ve found so far). zemscience.com. Retrieved on July 06, 2020.
5. ↑ 5.0 5.1 Fraser Cain (January 11, 2005). Three Largest Stars Discovered. universetoday.com. Retrieved on July 06, 2020.
6. ↑ IRAS 22317+5838. General Catalogue of Variable Stars. sai.msu.su. Retrieved on July 06, 2020.
7. ↑ Abramian, G. B. (1980). "New Variable M Supergiant Stars". Communications of the Byurakan Astrophysical Observatory (ComBAO) 52: 13-23. Bibcode: 1980SoByu..52...13A.

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