UX Antliae is a
post-AGB
The asymptotic giant branch (AGB) is a region of the Hertzsprung–Russell diagram populated by evolved cool luminous stars. This is a period of stellar evolution undertaken by all low- to intermediate-mass stars (about 0.5 to 8 solar masses) l ...
and
R Coronae Borealis variable
An R Coronae Borealis variable (abbreviated RCB, R CrB) is an eruptive variable star that varies in luminosity in two modes, one low amplitude pulsation (a few tenths of a magnitude), and one irregular, unpredictably-sudden fading by 1 to 9 ma ...
star that has a base
apparent magnitude
Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...
of around 11.85, with irregular dimmings down to below magnitude 18.0.
[
Researchers David Kilkenny and J.E. Westerhuys of the ]South African Astronomical Observatory
South African Astronomical Observatory (SAAO) is the national centre for optical and infrared astronomy in South Africa. It was established in 1972. The observatory is run by the National Research Foundation of South Africa. The facility's funct ...
confirmed that UX Antliae was an R Coronae Borealis variable in 1990 after noting the similarity of its spectrum to the RCB star W Mensae
W Mensae (W Men) is an unusual yellow supergiant star in the Large Magellanic Cloud in the southern constellation Mensa. It is an R Coronae Borealis variable and periodically decreases in brightness by several magnitudes.
W Men is very ...
.[ It had been suspected of being one since 1940, but had been little-studied and exhibited no characteristic declines between 1975 and 1990.][
Assuming that its absolute magnitude is around -5, it has been estimated as lying 25000 parsecs distant from Earth.][ Kilkenny and Westerhuys noted that its spectrum fit with that of a star of spectral class F, although was deficient in hydrogen.][ It has around 70% the mass of the Sun and an effective (surface) temperature of around 7000 K.]
See also
* R Coronae Borealis
References
External links
{{DEFAULTSORT:UX Antliae
Antlia
R Coronae Borealis variables
Antliae, UX
J10570905-3723550