![]() 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 | |
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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 | |
Database references | |
SIMBAD | data |
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]
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]