Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Scuptor |
Right ascension | 23h 53m 00.8742s |
Declination | −38° 51′ 46.6625″ |
Apparent magnitude (V) | 16.5 |
Characteristics | |
Evolutionary stage | white dwarf + brown dwarf |
Spectral type | D+T [1] |
Variable type | cataclysmic variable star |
Astrometry | |
Proper motion (μ) | RA: 81.036±0.043 mas/yr [2] Dec.: -63.109±0.050 mas/yr [2] |
Parallax (π) | 10.6786 ± 0.0524 mas [2] |
Distance | 305 ± 1 ly (93.6 ± 0.5 pc) |
Orbit [1] | |
Primary | BW Scu A |
Companion | BW Scu B |
Period (P) | 78.23 minutes |
Semi-major axis (a) | 0.58±0.02 R☉ |
Inclination (i) | 64.3±3.6° |
Semi-amplitude (K1) (primary) | 27.7±3.0 km/s |
Semi-amplitude (K2) (secondary) | 461±13 km/s |
Details [1] | |
BW Scl A | |
Mass | 0.85±0.04 M☉ |
BW Scl B | |
Mass | 53.4±6.3 MJup |
Radius | 1.03±0.05 RJup |
Other designations | |
RX J2353.0-3852, HE 2350-3908, 2MASS J23530086-3851465, MCT 2350-3908, TIC 183676876, AAVSO 2347-39 | |
Database references | |
SIMBAD | data |
BW Sculptoris is WZ Sge-type dwarf nova and a candidate period bouncer. The binary consists of a white dwarf and a brown dwarf donor that orbits the white dwarf every 78.23 minutes. BW Sculptoris is one of the closest and brightest cataclysmic variable stars with a brightness of magnitude16.5 and a distance of 93.3 parsecs. It also has the shortest period for any CVs known to date (as of August 2023). [1]
BW Sculptoris was discovered in 1997 by two teams. Abbott et al. discovered it with ROSAT as RX J2353.0-3852. [4] Augusteijn & Wisotzki discovered it independently in the Hamburg/ESO survey with the ESO 1.52 meter telescope and it was originally designated HE 2350–3908. [3] Both authors noted the low mass transfer. [4] [3] Earlier mass ratios hinted at a low mass donor and Neustroev & Mäntynen were able to narrow down the mass of the white dwarf to 0.85±0.04 M☉ and the mass of the donor to 0.051±0.006 M☉ (53.4±6.3 MJ), making the donor a brown dwarf. BW Sculptoris is a candidate period bouncer. This is an evolutionary stage of a cataclysmic variable in which a donor star looses enough mass to evolve into a substellar object or brown dwarf. This occurs together with a decrease of the orbital period until the period reaches 70–80 minutes, at which point the period increases again. It is suspected that BW Sculptoris already passed this minimum and that the orbital period will increase in the future. [1]
BW Sculptoris experienced a superoutburst with an amplitude of 7.5 mag in October 2011. The superoutburst was first detected by M. Linnolt (AAVSO) on October 21 with a visual magnitude of 9.6. On October 31 an ordinary superhump developed and on November 12 BW Sculptoris entered the rapid fading phase. [5] Even 10 years after the superoutburst the star has not returned to its pre-outburst level. [1]
EF Eridani is a variable star of the type known as polars, AM Herculis stars, or magnetic cataclysmic variable stars. Historically it has varied between apparent magnitudes 14.5 and 17.3, although since 1995 it has generally remained at the lower limit. The star system consists of a white dwarf with a substellar-mass former star in orbit.
DI Lacertae or Nova Lacertae 1910 was a nova in constellation Lacerta which appeared in 1910. It was discovered by Thomas Henry Espinell Compton Espin at Wolsingham Observatory on 30 Dec 1910, at which time it was an 8th magnitude object. Subsequent examination of pre-discovery photographic plates showed that the outburst occurred sometime between 17 November 1910 and 23 November 1910. It reached a peak brightness of magnitude 4.6 on 26 November 1910, making it visible to the naked eye. Before the nova event DI Lacertae was a 14th magnitude star, and by 1950 it had returned to 14th magnitude.
V1494 Aquilae or Nova Aquilae 1999 b was a nova which occurred during 1999 in the constellation Aquila and reached a brightness of magnitude 3.9 on 2 December 1999. making it easily visible to the naked eye. The nova was discovered with 14×100 binoculars by Alfredo Pereira of Cabo da Roca, Portugal at 18:50 UT on 1 December 1999, when it had a visual magnitude of 6.0.
An AM Canum Venaticorum star, is a rare type of cataclysmic variable star named after their type star, AM Canum Venaticorum. In these hot blue binary variables, a white dwarf accretes hydrogen-poor matter from a compact companion star.
AM Canum Venaticorum is a hydrogen-deficient cataclysmic variable binary star in the constellation of Canes Venatici. It is the type star of its class of variables, the AM Canum Venaticorum stars. The system consists of a white dwarf gaining matter via an accretion disk from a semi-degenerate or white dwarf companion.
WZ Sagittae is a cataclysmic dwarf nova star system in the constellation Sagitta. It consists of a white dwarf primary being orbited by a low mass companion. The white dwarf is about 0.85 solar masses while the companion is only 0.08 solar masses. This implies that the companion is a spectral class L2 star, although this has yet to be confirmed. The distance to this system has been determined by parallax, yielding a distance of 45.1 parsecs.
RX Andromedae is a variable star in the constellation of Andromeda. Although it is classified as a dwarf nova of the Z Camelopardalis (UGZ) type, it has shown low-luminosity periods typical of VY Sculptoris stars. However, for most of the time it varies from an apparent visual magnitude of 15.1 at minimum brightness to a magnitude of 10.2 at maximum brightness, with a period of approximately 13 days.
EK Trianguli Australis is a star in the constellation Triangulum Australe. It is a dwarf nova of the SU Ursae Majoris type that officially classified as such in 1980, after the characteristic eruptions of a short eruption and a supereruption were observed in May 1978 and June 1979 respectively. These systems are characterised by frequent eruptions and less frequent supereruptions. The former are smooth, while the latter exhibit short "superhumps" of heightened activity. The distance of the system has been assumed at 180 parsecs from the Solar System, for the donor star. Spectroscopic analysis and calculation gave an estimate of 125 parsecs.
QS Telescopii is a faint, well-studied binary star system in the southern constellation Telescopium. It is composed of a white dwarf and main sequence donor star, locked into a close, circular orbit facing one another. Known as polars, material from the donor star does not form an accretion disk around the white dwarf, but rather streams directly onto it. This is due to the presence of the white dwarf's strong magnetic field. The pair undergo frequent shifts between a high and low accretion states, and it shifts between single and double accretion poles. The main pole is partially self-eclipsing.
SS Ursae Minoris is a cataclysmic variable star system in the constellation Ursa Minor. It was discovered visually and by its X-ray emissions separately in 1982 before they were understood to be coming from the same object. It is classified as a SU Ursae Majoris variable subclass of dwarf nova in that it has both 'normal' outbursts of increased brightness as well as even brighter 'superoutbursts'. However, unlike other SU Ursae Majoris stars, the superoutbursts are of longer duration than the regular outbursts.
LL Andromedae is a dwarf nova in the constellation Andromeda, discovered during an outburst in 1979. Its typical apparent visual magnitude is 19.4, but undergoes outbursts events when can reach a peak magnitude of 14.3. Since this magnitude is reached during the most powerful outbursts, while less bright outbursts can occur, it is classified as a SU Ursae Majoris variable.
PX Andromedae is an eclipsing cataclysmic variable star in the constellation Andromeda. It has been classified as a SW Sextantis variable, and its apparent visual magnitude varies between 14.04 and 17.
V455 Andromedae is a dwarf nova in the constellation Andromeda. It has a typical apparent visual magnitude of 16.5, but reached a magnitude of 8.5 during the only observed outburst.
QZ Aurigae, also known as Nova Aurigae 1964, was a nova which occurred in the constellation Auriga during 1964. It was discovered by Nicholas Sanduleak on an objective prism photographic plate taken at the Warner and Swasey Observatory on 4 November 1964. Examination of pre-discovery plates from Sonneberg Observatory showed that the eruption occurred in early February 1964, and it had a photographic magnitude of 6.0 on 14 February 1964. Its brightness declined in images taken after the 14th, suggesting that its peak brightness was above 6.0. It was probably visible to the naked eye for a short time.
GI Monocerotis, also known as Nova Monocerotis 1918, was a nova that erupted in the constellation Monoceros during 1918. It was discovered by Max Wolf on a photographic plate taken at the Heidelberg Observatory on 4 February 1918. At the time of its discovery, it had a photographic magnitude of 8.5, and had already passed its peak brightness. A search of plates taken at the Harvard College Observatory showed that it had a photographic magnitude of 5.4 on 1 January 1918, so it would have been visible to the naked eye around that time. By March 1918 it had dropped to ninth or tenth magnitude. By November 1920 it was a little fainter than 15th magnitude.
BZ Ursae Majoris is a dwarf nova star system in the northern circumpolar constellation of Ursa Major. It consists of a white dwarf primary in a close orbit with a red dwarf. The latter star is donating mass, which is accumulating in an accretion disk orbiting the white dwarf. The system is located at a distance of approximately 505 light years from the Sun based on parallax measurements.
RZ Leonis Minoris is a cataclysmic variable star system in the northern constellation of Leo Minor. It undergoes frequent outbursts that vary in brightness from an apparent visual magnitude of 14.4 down to 16.8. Based on parallax measurements, this system is located at a distance of approximately 2,160 light years from the Sun.
SW Ursae Majoris is a cataclysmic binary star system in the northern circumpolar constellation of Ursa Major, abbreviated SW UMa. During quiescence it has an apparent visual magnitude of 16.5–17, which is too faint to be visible to the naked eye. Based on parallax measurements, it is located at a distance of approximately 526 light years from the Sun.
ER Ursae Majoris is a variable star in the northern circumpolar constellation of Ursa Major, abbreviated ER UMa. It is a prototype system for a subclass of SU Ursae Majoris dwarf novae. The system ranges in brightness from a peak apparent visual magnitude of 12.4 down to 15.2, which is too faint to be visible to the naked eye. The distance to this system, based on parallax measurements, is approximately 1,163 light years.
CR Boötis is an interacting binary system in the northern constellation of Boötes, abbreviated CR Boo. It is one of the best-known AM Canum Venaticorum stars. The system varies widely in brightness, ranging in apparent visual magnitude from 13.6 down to 17.5. The distance to this system is approximately 1,150 light years from the Sun, based on parallax measurements.