Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Pyxis |
Right ascension | 08h 58m 39.03s [2] |
Declination | −24° 35′ 10.6″ [2] |
Apparent magnitude (V) | 11.49 [3] |
Characteristics | |
Spectral type | A4V + M3V [4] |
Variable type | Delta Scuti variable [3] |
Astrometry | |
Proper motion (μ) | RA: −13.830 [2] mas/yr Dec.: +6.985 [2] mas/yr |
Parallax (π) | 1.4301 ± 0.0341 mas [2] |
Distance | 2,280 ± 50 ly (700 ± 20 pc) |
Orbit [4] | |
Period (P) | 1.15 d |
Eccentricity (e) | 0.0 |
Inclination (i) | 25-30° |
Semi-amplitude (K1) (primary) | 17.8±0.4 km/s |
Details | |
Hot star | |
Mass | 1.85±0.05 [4] M☉ |
Radius | 1.9 [2] R☉ |
Luminosity | 27 [2] L☉ |
Surface gravity (log g) | 4.21 [2] cgs |
Temperature | 9,431 [2] K |
Metallicity [Fe/H] | +0.09 [2] dex |
Rotation | 1.5 d [4] |
Rotational velocity (v sin i) | 52 [5] km/s |
Age | 316 [2] Myr |
Cool star | |
Mass | 0.3 [4] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
XX Pyxidis is a star located in the constellation Pyxis. It has an apparent magnitude that varies slightly at about 11.5, and is about 2,300 light years away.
XX Pyxidis is one of the more-studied members of a class of stars known as Delta Scuti variables [4] —short-period (six hours at most) pulsating stars that have been used as standard candles and as subjects to study astroseismology. [7] 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±0.05 times as massive as the Sun. Its companion is most likely a red dwarf 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, [4] and pulsates in several overlapping modes 26-76 times per day. [8]
Delta Scuti, Latinized from δ Scuti, is a variable star in the southern constellation Scutum. With an apparent visual magnitude that fluctuates around 4.72, it is the fifth-brightest star in this small and otherwise undistinguished constellation. Analysis of the parallax measurements place this star at a distance of about 199 light-years from Earth. It is drifting closer with a radial velocity of −45 km/s.
Gamma Doradus variables are variable stars which display variations in luminosity due to non-radial pulsations of their surface. The stars are typically young, early F or late A type main sequence stars, and typical brightness fluctuations are 0.1 magnitudes with periods on the order of one day. This class of variable stars is relatively new, having been first characterized in the second half of the 1990s, and details on the underlying physical cause of the variations remains under investigation.
Delta Apodis is the Bayer designation for a double star in the southern constellation of Apus.
Chi Aquarii, Latinized from χ Aquarii, is the Bayer designation of a star in the equatorial constellation of Aquarius. The distance to this star, based upon parallax measurements with a 7% margin of error, is roughly 610 light-years. It is visible to the naked eye with an apparent visual magnitude of about 5.
28 Andromedae is a Delta Scuti variable star in the constellation Andromeda. 28 Andromedae is the Flamsteed designation. It also bears the variable star name GN Andromedae. Its apparent magnitude is 5.214, varying by less than 0.1 magnitudes.
26 Arietis is a variable star in the northern constellation of Aries. 26 Arietis is the Flamsteed designation; it also bears the variable star designation UU Arietis. The apparent visual magnitude of this star is 6.14, which, according to the Bortle Dark-Sky Scale, is within the naked eye visibility limit in dark rural skies. The annual parallax shift of 13.78 mas is equivalent to a distance of approximately 215 light-years from Earth. The star is receding from the Earth with a heliocentric radial velocity of +15 km/s.
Kappa Boötis is a double star in the constellation Boötes. It has the traditional name Asellus Tertius and the Flamsteed designation 17 Boötis. The components are separated by an angular distance of 13.5 arcsec, viewable in a small telescope. Kappa Boötis is approximately 155 light years from Earth.
Rapidly oscillating Ap stars (roAp stars) are a subtype of the Ap star class that exhibit short-timescale rapid photometric or radial velocity variations. The known periods range between 5 and 23 minutes. They lie in the δ Scuti instability strip on the main sequence.
Delta Delphini, Latinized from δ Delphini, is a binary star in the northern constellation of Delphinus. It is visible to the naked eye with an apparent visual magnitude of 4.43. Based upon an annual parallax shift of 14.61 mas as seen from the Earth, the system is located about 223 light years from the Sun.
TX Camelopardalis is a Mira-type variable star in the constellation Camelopardalis. It is a classical long period variable star with pulsational period of 558.7 days. Water masers have been observed around the star.
Delta Sagittae is a binary star in the constellation of Sagitta, with an apparent magnitude of +3.68. The primary component is a red M-type bright giant, and the secondary is a B-type main-sequence star. It is approximately 430 light years from Earth, based on its Gaia Data Release 2 parallax.
Rho Pavonis, Latinized from ρ Pavonis, is a single, variable star in the southern constellation of Pavo. It is yellow-white in hue and faintly visible to the naked eye with an apparent visual magnitude that fluctuates around 4.86. The star is located at a distance of approximately 190 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +8 km/s. It is a candidate outlying member of the Tucana Association of co-moving stars.
HY Velorum is a binary star system in the southern constellation of Vela. It is a dim star but visible to the naked eye with an apparent visual magnitude of 4.83. The distance to this system, as estimated from its annual parallax shift of 7.1 mas, is 460 light years. HY Vel most likely forms a gravitationally bound pair with the magnitude 5.45 binary system KT Vel ; both are members of the IC 2391 open cluster. As of 1998, HY Vel and KT Vel had an angular separation of 76.1″ along a position angle of 311°.
AH Scorpii is a red supergiant variable star located in the constellation Scorpius. It is one of the largest stars known by radius and is also one of the most luminous red supergiant stars in the Milky Way.
X Crucis is a classical Cepheid variable star in the southern constellation of Crux.
UZ Pyxidis is a semiregular variable star in the constellation Pyxis. It is located about 3,600 light-years away from the Earth.
V473 Lyrae is a variable star in the constellation Lyra. It is an unusual Classical Cepheid variable with a visual range of 5.99 to 6.35.
XX Persei is a semiregular variable red supergiant star in the constellation Perseus, between the Double Cluster and the border with Andromeda.
BO Carinae, also known as HD 93420, is an irregular variable star in the constellation Carina.
FG Virginis is a well-studied variable star in the equatorial constellation of Virgo. It is a dim star, near the lower limit of visibility to the naked eye, with an apparent visual magnitude that ranges from 6.53 down to 6.58. The star is located at a distance of 273.5 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +16 km/s. Because of its position near the ecliptic, it is subject to lunar occultations.