PX Andromedae
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| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 00h 30m 05.8084s[2] |
| Declination | +26° 17′ 26.439″[2] |
| Apparent magnitude (V) | 14.04 – 17.00 variable[3] |
| Characteristics | |
| Spectral type | pec(UG)[3] |
| Apparent magnitude (B) | 11.84[4] |
| Apparent magnitude (R) | 14.69[4] |
| Apparent magnitude (G) | 14.8494[2] |
| Apparent magnitude (J) | 14.652[5] |
| Apparent magnitude (H) | 14.485[5] |
| Apparent magnitude (K) | 14.344[5] |
| Variable type | SW Sex[4] |
| Astrometry | |
| Proper motion (μ) | RA: −10.924±0.081 [2] mas/yr Dec.: −10.992±0.052[2] mas/yr |
| Parallax (π) | 1.2323±0.0437 mas[2] |
| Distance | 2,650 ± 90 ly (810 ± 30 pc) |
| Orbit | |
| Period (P) | 3.5112 hours[6] |
| Other designations | |
| 2MASS J00300581+2617264, AAVSO 0024+25, 2XMM J003005.7+261727, PG 0027+260 | |
| Database references | |
| SIMBAD | data |
PX Andromedae (often abbreviated to PX And) is an eclipsing cataclysmic variable star in the constellation Andromeda. It has been classified as a SW Sextantis variable,[4] and its apparent visual magnitude varies between 14.04 and 17.[3]
In 1982, Richard Green et al. listed PX Andromedae as a possible cataclysmic variable, based on spectra taken with the Hale Telescope.[7] Observations in 1989 by Li Yong et al, at the Beijing Observatory detected rapid variations of the star's brightness of up to 0.2 magnitudes, as well as eclipses which occur every 3.5 hours.[8] In 1992 the star was given the variable star designation PX Andromedae.[9]
The spectrum of PX Andromedae is variable, but typically shows a continuum with prominent broad emission lines of hydrogen and helium. Unlike many types of cataclysmic variable, the emission lines are generally single-peaked, although for a short time during each orbit they do show a double peak due to an absorption core within the emission lines. The single-peaked lines are shown in novae and dwarf novae outbursts, and PX Andromedae is often described as nova-like although it does not shown outbursts with large increases in brightness. However, it does have high and low states with the low states generally being fainter and showing weaker emission.[10]
PX Andromedae is a very blue star with an ultraviolet excess, indicating that it includes very hot objects.[10]
