XX Pyxidis is a
star
A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...
located in the constellation
Pyxis. It has an
apparent magnitude that varies slightly at about 11.5, and is about 2,300
light year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...
s away.
XX Pyxidis is one of the more-studied members of a class of stars known as
Delta Scuti variables
—short-period (six hours at most) pulsating stars that have been used as
standard candles
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A ''direct'' distance measurement of an astronomical object is possible o ...
and as subjects to study
astroseismology.
[ Astronomers made more sense of its pulsations when it became clear that it is also a binary star system. The main star is a white main sequence star of spectral type A4V that is around 1.85 times as massive as the Sun. Its companion is most likely a ]red dwarf
''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave since 2009, gaining a cult following. T ...
star of spectral type M3V, around 0.3 times as massive as the Sun. The two are very close—possibly only 3 times the diameter of the Sun between them—and orbit each other every 1.15 days. The brighter star is deformed into an egg-shape,[
]
References
{{DEFAULTSORT:XX Pyxidis
Pyxis
Pyxidis, XX
Delta Scuti variables
CD-24 7599
J08583903-2435106
A-type main-sequence stars
M-type main-sequence stars
Binary stars