XX Pyxidis

XX Pyxidis

Visual band light curves for XX Pyxidis, adapted from Arentoft et al. (2001)[1]
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]
Distance2,280 ± 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
Mass1.85±0.05[4] M☉
Radius1.9[2] R☉
Luminosity27[2] L☉
Surface gravity (log g)4.21[2] cgs
Temperature9,431[2] K
Metallicity [Fe/H]+0.09[2] dex
Rotation1.5 d[4]
Rotational velocity (v sin i)52[5] km/s
Age316[2] Myr
Cool star
Mass0.3[4] M☉
Other designations
XX Pyxidis, CD−24 7599, GSC 06589-00261[6]
Database references
SIMBADdata

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]

  1. ^ Cite error: The named reference Arentoft was invoked but never defined (see the help page).
  2. ^ a b c d e f g h i j k Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  3. ^ a b Cite error: The named reference gcvs was invoked but never defined (see the help page).
  4. ^ a b c d e f g Cite error: The named reference Aerts 2002 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference chang2013 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference vsx was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference bedding2020 was invoked but never defined (see the help page).