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VW Leonis Minoris

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VW Leonis Minoris

A light curve VW Leonis Minoris, plotted from TESS data[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Leo Minor
Right ascension 11h 02m 51.910s[2]
Declination 30° 24′ 54.70″[2]
Apparent magnitude (V) 8.07[3]
Characteristics
Spectral type F2V + G2V[4]
B−V color index +0.410±0.015[3]
Variable type Suspected W UMa[5]
Astrometry
Radial velocity (Rv)+5.00±0.75[3] km/s
Proper motion (μ) RA: +12.304 mas/yr[2]
Dec.: −4.764 mas/yr[2]
Parallax (π)8.8238 ± 0.1046 mas[2]
Distance370 ± 4 ly
(113 ± 1 pc)
Absolute magnitude (MV)2.46[3]
Orbit – Contact (1 & 2)[6]
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)[6]
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)[6]
Period (P)355.02±0.17 d
Eccentricity (e)0.097±0.011
Periastron epoch (T)2,453,046±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[7] M
Radius1.69±0.02[7] R
Luminosity8.73[3] L
Surface gravity (log g)4.21±0.02[7] cgs
Component 2
Mass0.71±0.02[7] M
Radius1.18±0.02[7] R
Surface gravity (log g)4.14±0.02[7] cgs
Other designations
VW LMi, BD+31°2225, HD 95660, HIP 54003, SAO 62372[8]
Database references
SIMBADdata

VW Leo Minoris is a tight quadruple[6] star system, located in the constellation of Leo Minor. With a peak combined apparent visual magnitude of 8.07,[3] it is too faint to be seen with the naked eye. Parallax measurements give a distance estimate of approximately 370 light years from the Sun, and it is drifting further away with a radial velocity of +5 km/s.[3]

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[7] 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.[5] 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.[6] They have a combined stellar classification of F2V, matching an F-type main sequence star.[4]

In 2006 an additional, detached binary component was discovered, making this a quadruple star system.[9] This binary has an orbital period of 7.93 days, a mild eccentricity (ovalness) of 0.04,[6] and it shows an apsidal precession with a period of 78.6±1.6 years.[4] The components (3 & 4) have a combined stellar class of G2V,[4] showing a match with a G-type main-sequence star.[4]

The two binaries (1–2 & 3–4) orbit each other with a period of 355 days and an eccentricity of 0.1.[6] 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.[4] 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.[6]

References

[edit]
  1. ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
  2. ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  3. ^ 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.
  4. ^ 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.
  5. ^ 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.
  6. ^ 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.
  7. ^ 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.
  8. ^ "VW LMi". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-02-05.{{cite web}}: CS1 maint: postscript (link)
  9. ^ 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.