![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/d/d5/Sculptor_constellation_map.svg/640px-Sculptor_constellation_map.svg.png&w=640&q=50)
R Sculptoris
Variable star in the constellation Sculptor / From Wikipedia, the free encyclopedia
R Sculptoris is a variable star system in the southern constellation of Sculptor.[11][12] Parallax measurements provide a distance estimate of approximately 1,435 ± 98 light-years from the Sun.[1] An independent estimate based on measurements of an ejected shell surrounding the star yield a distance of 1,180 ± 140 light-years.[6] The star is drifting closer with a radial velocity of −5.4 km/s.[5]
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/a/ae/RSclLightCurve.png/640px-RSclLightCurve.png)
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Sculptor |
Right ascension | 01h 26m 58.09462s[1] |
Declination | −32° 32′ 35.4377″[1] |
Apparent magnitude (V) | +5.72[2] |
Characteristics | |
Spectral type | C6,5ea(Np)[3] |
U−B color index | +7.67[2] |
B−V color index | +3.87[2] |
Variable type | SRb[4] |
Astrometry | |
Radial velocity (Rv) | −5.40[5] km/s |
Proper motion (μ) | RA: −9.784[1] mas/yr Dec.: −30.900[1] mas/yr |
Parallax (π) | 2.2724 ± 0.1471 mas[1] |
Distance | 1177±143 ly (361±44 pc)[6] |
Absolute magnitude (MV) | −0.45[7] |
Details[8] | |
Mass | 1.3±0.7 M☉ |
Radius | 355±55,[8] 513[9] R☉ |
Luminosity | 5,495+2,822 −1,865 L☉ |
Surface gravity (log g) | −0.6±0.4 cgs |
Temperature | 2640±80 K |
Metallicity [Fe/H] | 0.0[3] dex |
Other designations | |
Database references | |
SIMBAD | data |
This is an aging giant star on the asymptotic giant branch with a stellar classification of C6,5ea(Np),[3] which indicates a carbon-rich atmosphere. It is a semi-regular pulsating star of the SRb[4] type that is nearing the end of its fusing lifespan. A sine curve fitted to the last ten pulsation cycles prior to 2017 give a pulsation period of 376 days with an amplitude of 0.75 magnitude. The star is shedding its outer atmosphere, and it is surrounded by a thin shell of dust and gas that was created during the most recent thermal pulse around 2,000 years ago.[6]
Observations have revealed a spiral structure in the material around the star.[14] The spiral is suspected to be caused by an unseen companion star.[11] The spiral windings are consistent with an orbital period of ~350 years.[14]