VW Leonis Minoris

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VW Leonis Minoris
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Leo Minor
Right ascension 11h 02m 51.90926s[1]
Declination 30° 24′ 54.7229″[1]
Apparent magnitude (V) 8.07[2]
Characteristics
Spectral type F2V + G2V[3]
B−V color index +0.410±0.015[2]
Variable type Suspected W UMa[4]
Astrometry
Radial velocity (Rv)+5.00±0.75[2] km/s
Proper motion (μ) RA: +13.303[1] mas/yr
Dec.: −6.083[1] mas/yr
Parallax (π)9.0488 ± 0.1200[1] mas
Distance360 ± 5 ly
(111 ± 1 pc)
Absolute magnitude (MV)2.46[2]
Orbit – Contact (1 & 2)[5]
Period (P)11.461225 h
Eccentricity (e)0.0
Semi-amplitude (K1)
(primary)		105.8±1.0 km/s
Semi-amplitude (K2)
(secondary)		250.2±1.2 km/s
Orbit – Non-contact (3 & 4)[5]
Period (P)7.93063 d
Eccentricity (e)0.035±0.003
Periastron epoch (T)2,452,274.54±0.11 HJD
Argument of periastron (ω)
(secondary)		1.90±0.09°
Semi-amplitude (K1)
(primary)		63.99±0.23 km/s
Semi-amplitude (K2)
(secondary)		65.53±0.27 km/s
Orbit – Mutual (12 & 34)[5]
Period (P)355.02±0.17 d
Eccentricity (e)0.097±0.011
Periastron epoch (T)2,453,046±6 HJD
Argument of periastron (ω)
(secondary)		2.20±0.12°
Semi-amplitude (K1)
(primary)		21.61±0.49 km/s
Semi-amplitude (K2)
(secondary)		23.22±0.33 km/s
Details
Component 1
Mass1.68±0.02[6] M☉
Radius1.69±0.02[6] R☉
Luminosity8.73[2] L☉
Surface gravity (log g)4.21±0.02[6] cgs
Component 2
Mass0.71±0.02[6] M☉
Radius1.18±0.02[6] R☉
Surface gravity (log g)4.14±0.02[6] cgs
Other designations
VW LMi, BD+31°2225, HD 95660, HIP 54003, SAO 62372[7]
Database references
SIMBADdata

VW Leo Minoris is a tight quadruple[5] star system, located in the constellation of Leo Minor. With a peak combined apparent visual magnitude of 8.07,[2] it is too faint to be seen with the naked eye. Parallax measurements give a distance estimate of approximately 360 light years from the Sun, and it is drifting further away with a radial velocity of +5 km/s.[2]

Component 1
Period = 0.48 d
Component 2
Period = 355.02 d
Component 3
Period = 7.93 d
Component 4

Hierarchy of orbits

This system was found to be variable using observations with the Hipparcos satellite. It is classified as an A-type[6] W Ursae Majoris eclipsing binary, where the two stars share a common envelope. The eclipse of the primary causes the magnitude of the system to drop to 8.45.[4] These components (1 & 2) have an orbital period of 11.4611 hours and the orbital plane has an inclination of 72.4° to the line of sight from the Earth.[5] They have a combined stellar classification of F2V, matching an F-type main sequence star.[3]

In 2006 an additional, detached binary component was discovered, making this a quadruple star system.[8] This binary has an orbital period of 7.93 days, a mild eccentricity (ovalness) of 0.04,[5] and it shows an apsidal precession with a period of 78.6±1.6 years.[3] The components (3 & 4) have a combined stellar class of G2V,[3] showing a match with a G-type main-sequence star.[3]

The two binaries (1–2 & 3–4) orbit each other with a period of 355 days and an eccentricity of 0.1.[5] The plane of their orbit is close to coplanar (within 5°) with the orbital plane of the detached binary. This outer orbit appears stable, suggesting there is no additional outlying component to this system.[3] The nearby ninth magnitude star HD 95606 (HIP 53969) shares a common proper motion with this system and may be loosely gravitationally bound. They likely all formed in the same protostellar cloud.[5]

References[]

  1. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ a b c d e f g Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  3. ^ a b c d e f Pribulla, T.; et al. (May 2020), "Secular changes in the orbits of the quadruple system VW LMi", Monthly Notices of the Royal Astronomical Society, 494 (1): 178–189, arXiv:2003.08169, Bibcode:2020MNRAS.494..178P, doi:10.1093/mnras/staa699.
  4. ^ a b Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
  5. ^ a b c d e f g h Pribulla, T.; et al. (October 2008), "VW LMi: tightest quadruple system known. Light-time effect and possible secular changes of orbits", Monthly Notices of the Royal Astronomical Society, 390 (2): 798–806, arXiv:0808.0129, Bibcode:2008MNRAS.390..798P, doi:10.1111/j.1365-2966.2008.13781.x, S2CID 14256305.
  6. ^ a b c d e f g Djurašević, G.; et al. (March 2013), "Photometric Analysis of HS Aqr, EG Cep, VW LMi, and du Boo", The Astronomical Journal, 145 (3): 10, Bibcode:2013AJ....145...80D, doi:10.1088/0004-6256/145/3/80, 80.
  7. ^ "VW LMi". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-02-05.CS1 maint: postscript (link)
  8. ^ Pribulla, Theodor; Rucinski, Slavek M. (June 2006), "Contact Binaries with Additional Components. I. The Extant Data", The Astronomical Journal, 131 (6): 2986–3007, arXiv:astro-ph/0601610, Bibcode:2006AJ....131.2986P, doi:10.1086/503871, S2CID 15762240.
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