T Pyxidis
T Pyxidis (T Pyx) is a recurrent nova and nova remnant in the constellation Pyxis. It is a binary star system and its distance is estimated at about 4,783 parsecs (15,600 light-years) from Earth. It contains a Sun-like star and a white dwarf. Because of their close proximity and the larger mass of the white dwarf, the latter draws matter from the larger, less massive star. The influx of matter on the white dwarf's surface causes periodic thermonuclear explosions to occur.
T Pyx surrounded by the nova remnants of a previous outburst. Hubble Space Telescope composite | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pyxis |
| Right ascension | 09h 04m 41.5062s |
| Declination | −32° 22′ 47.5033″ |
| Apparent magnitude (V) | 6.4 Max. 18.5 Min. |
| Characteristics | |
| Spectral type | White Dwarf |
| Variable type | Recurrent nova |
| Astrometry | |
| Proper motion (μ) | RA: −2.531±0.052 mas/yr Dec.: 0.177±0.062 mas/yr |
| Parallax (π) | 0.3051 ± 0.0419 mas |
| Distance | 3185+607 −283 pc |
| Details | |
| White dwarf | |
| Mass | 0.7±0.2 M☉ |
| Second component | |
| Mass | 0.14±0.03 M☉ |
| Orbit | |
| Period (P) | 1.8295 hours |
| Inclination (i) | 10±2° |
| Other designations | |
| Database references | |
| SIMBAD | data |
The usual apparent magnitude of this star system is 15.5, but there have been observed eruptions with maximal apparent magnitude of about 7.0 in the years 1890, 1902, 1920, 1944, 1966 and 2011. Evidence seems to indicate that T Pyxidis may have increased in mass despite the nova eruptions, and is now close to the Chandrasekhar limit when it might explode as a supernova. When a white dwarf reaches this limit it will collapse under its own weight and cause a type Ia supernova.