V803 Centauri
Star in the constellation Centaurus
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V803 Centauri (V803 Cen) is a cataclysmic binary consisting of a dwarf helium star losing mass to a white dwarf. It is an example of the AM Canum Venaticorum (AM CVn) type of cataclysmic variable stars.[1]
Three light curves for V803 Centauri, on three timescales, hours (plot A), days (plot B) and years (plot C). Adapted from Patterson et al. (2000),[1] Kato et al. (2004)[2] and Levitan et al. (2015)[3] | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 13h 23m 44.54s[4] |
| Declination | −41° 44′ 29.54″[4] |
| Apparent magnitude (V) | 12.7 - 17.7[5] |
| Characteristics | |
| Spectral type | pec |
| U−B color index | −0.9 - −1.0[6] |
| B−V color index | +0.1[6] |
| Variable type | AM CVn[7] |
| Astrometry | |
| Proper motion (μ) | RA: −3.907[4] mas/yr Dec.: +11.978[4] mas/yr |
| Parallax (π) | 3.4885±0.0599 mas[4] |
| Distance | 930 ± 20 ly (287 ± 5 pc) |
| Absolute magnitude (MV) | 5.93[7] |
| Details | |
| White dwarf | |
| Mass | 0.8 - 1.2[7] M☉ |
| Donor star | |
| Mass | 0.06 - 0.11[7] M☉ |
| Other designations | |
| V803 Centauri, V803 Cen, AE-1, 2MASS J13234454-4144294, AAVSO 1317-41. | |
| Database references | |
| SIMBAD | data |
Aina Margareta Elvius announced the discovery of this star in 1975.[8] It was given its variable star designation, V803 Centauri, in 1978.[9] The light curve shows a "low state" at about magnitude 17, with rapid outbursts of several magnitudes lasting only a few days or brighter super-outbursts lasting a few weeks, and a "high state" at up to 13th magnitude. V803 Centauri is most often seen in the high state, where it may stay bright for a year or more.[10]
The donor star has been radically stripped of material and now only around 0.1 M☉ remains. With its outer layers removed, the helium core has expanded and cooled and is almost impossible to detect directly. The accreting white dwarf has a temperature around 14,000 K.[11] Most of the light from V803 Cen is produced by an accretion disk, especially when the system is in outburst. The accretion disk shows a blackbody temperature around 30,000 K.[12]