RW Cephei | |
---|---|
Observational Data | |
Designation | Rw Cep HD 21246 HIP 110504 |
Right ascension | 22h 23m 07.0152s[1][2] |
Declination | +55° 57′ 47.6161″[1][2] |
Constellation | Cepheus |
Type of object | Supergiant star |
Magnitude | Apparent Mag: +6.44[3] Absolute Mag: -3.18 / -4.02[3] |
Astrometry | |
Distance from Earth | 4026.71 ly[3] |
Radial velocity | -56.00 ± 5.7 km/s[1][4] |
Proper motion | RA: -3.616 mas/yr[1][2] Dec: -2.349mas/yr[1][2] |
Parallax | 0.2357 ± 0.0944 mas[1][2] |
RW Cephei (Rw Cep, HD 21246, HIP 110504) is a supergiant star in the constellation of Cepheus.[3] It is not part of the constellation itself, but does lie within the borders of Cepheus. The star is one of the largest stars known with a radius nearly 1,600 greater than the Sun's.[5] The star is sufficiently bright that it does not require binoculars or a telescope to observe it.
RW Cephei is situated roughly 4026.71 light years from Earth.[3] The star is truly huge, thought to have a radius of 1,535 solar radii and a mass of 13.7 solar masses.[5] The temperature of the star is thought to be low at 590 kelvin.[3] The prefix "RV" in the name identifies RW Cephei as a variable star, meaning its brightness changes over time. It is classified as a pulsating, slow regular variable. The Star slowly expands and contracts over time in a regular and predictable manner. As it does so, the brightness varies between +6.456 and +6.620 over a period of 0.170 days or four hours.[3][6]
The star is not known to have any exoplanets.
Categories: [Astronomy] [Stars]