XX Pyxidis

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XX Pyxidis
XXPyxLightCurve.png
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]
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
XX Pyxidis, CD−24 7599, GSC  06589-00261 [6]
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]

Related Research Articles

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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.

<span class="mw-page-title-main">Gamma Doradus variable</span> Type of variable star

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.

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<span class="mw-page-title-main">Chi Aquarii</span> Star in the constellation Aquarius

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<span class="mw-page-title-main">28 Andromedae</span> Star in the constellation Andromeda

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.

<span class="mw-page-title-main">26 Arietis</span> Star in the constellation Aries

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<span class="mw-page-title-main">Kappa Boötis</span> Double star in the constellation of Boötes

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.

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<span class="mw-page-title-main">Delta Delphini</span> Star in the constellation Delphinus

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.

<span class="mw-page-title-main">TX Camelopardalis</span> Star in the constellation Camelopardalis

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<span class="mw-page-title-main">Delta Sagittae</span> Binary star system in the constellation Sagitta

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<span class="mw-page-title-main">Rho Pavonis</span> Variable star in the constellation Pavo

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.

<span class="mw-page-title-main">HY Velorum</span> Star in the constellation Vela

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°.

<span class="mw-page-title-main">AH Scorpii</span> Star in the constellation Scorpius

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.

<span class="mw-page-title-main">X Crucis</span> Variable star in the constellation Crux

X Crucis is a classical Cepheid variable star in the southern constellation of Crux.

<span class="mw-page-title-main">UZ Pyxidis</span> Star in the constellation Pyxis

UZ Pyxidis is a semiregular variable star in the constellation Pyxis. It is located about 3,600 light-years away from the Earth.

<span class="mw-page-title-main">V473 Lyrae</span> Star in the constellation Lyra

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.

<span class="mw-page-title-main">XX Persei</span> Star in the constellation Perseus

XX Persei is a semiregular variable red supergiant star in the constellation Perseus, between the Double Cluster and the border with Andromeda.

<span class="mw-page-title-main">BO Carinae</span> Star in the constellation Carina

BO Carinae, also known as HD 93420, is an irregular variable star in the constellation Carina.

<span class="mw-page-title-main">FG Virginis</span> Variable star in the constellation Virgo

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.

References

  1. Arentoft, T.; Sterken, C.; Handler, G. (September 2001). "Low-frequency variability and binarity of the δ Scuti star XX Pyx". Monthly Notices of the Royal Astronomical Society. 326 (1): 192–202. Bibcode:2001MNRAS.326..192A. doi: 10.1046/j.1365-8711.2001.04594.x .
  2. 1 2 3 4 5 6 7 8 9 10 11 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. 1 2 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
  4. 1 2 3 4 5 6 7 Aerts, C.; Handler, G.; Arentoft, T.; Vandenbussche, B.; Medupe, R.; Sterken, C. (2002). "The δ Scuti star XX Pyx is an ellipsoidal variable". Monthly Notices of the Royal Astronomical Society. 333 (2): L35–L39. Bibcode:2002MNRAS.333L..35A. doi: 10.1046/j.1365-8711.2002.05627.x .
  5. Chang, S.-W.; et al. (2013). "Statistical Properties of Galactic δ Scuti Stars: Revisited". The Astronomical Journal. 145 (5): 10. arXiv: 1303.1031 . Bibcode:2013AJ....145..132C. doi:10.1088/0004-6256/145/5/132. S2CID   118900730. 132.
  6. "XX Pyxidis". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 5 September 2015.
  7. Templeton, Matthew (16 July 2010). "Delta Scuti and the Delta Scuti Variables". Variable Star of the Season. AAVSO (American Association of Variable Star Observers). Retrieved 5 September 2015.
  8. Bedding, Timothy R.; et al. (2020). "Very regular high-frequency pulsation modes in young intermediate-mass stars". Nature. 581 (7807): 147–151. arXiv: 2005.06157 . Bibcode:2020Natur.581..147B. doi:10.1038/s41586-020-2226-8. PMID   32405022. S2CID   218613877.