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HD 111395 is a single,[12] variable star in the northern constellation of Coma Berenices. It has the variable star designation LW Com, short for LW Comae Berenices;[5] HD 111395 is the Henry Draper Catalogue designation. The star has a yellow hue and is just bright enough to be barely visible to the naked eye with an apparent visual magnitude that fluctuates around 6.29.[3] Based upon parallax measurements, it is located at a distance of 55.8 light years from the Sun.[2] The star is drifting closer with a radial velocity of −8.9 km/s.[6] It is a member of the Eta Chamaeleontis stellar kinematic group.[13]

HD 111395

A visual band light curve for LW Comae Berenices, adapted from Strassmeier et al. (1997)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Coma Berenices
Right ascension 12h 48m 47.048s[2]
Declination +24° 50′ 24.82″[2]
Apparent magnitude (V) 6.29[3]
Characteristics
Evolutionary stage main sequence
Spectral type G7V[4]
B−V color index 0.703±0.002[3]
Variable type BY Dra[5]
Astrometry
Radial velocity (Rv)−8.936±0.0064[6] km/s
Proper motion (μ) RA: −334.908 mas/yr[2]
Dec.: −105.517 mas/yr[2]
Parallax (π)58.4858 ± 0.0293 mas[2]
Distance55.77 ± 0.03 ly
(17.098 ± 0.009 pc)
Absolute magnitude (MV)5.15[3]
Details
Mass1.08±0.04[7] M☉
Radius0.93±0.01[8] R☉
Luminosity0.799±0.001[8] L☉
Surface gravity (log g)4.543±0.05[7] cgs
Temperature5,649+38
−17[8] K
Metallicity [Fe/H]0.08±0.02[7] dex
Rotational velocity (v sin i)3.8±0.8[7] km/s
Age1.0[9] or 1.01−1.73[10] Gyr
Other designations
LW Com, BD+25°2568, FK5 3021, GJ 486.1, HD 111395, HIP 62523, HR 4864, SAO 82511[11]
Database references
SIMBADdata

This object is a G-type main-sequence star with a stellar classification of G7V.[4] It is a BY Draconis variable that varies in brightness by about 0.10 magnitude over a period of 15.8 days,[5] which is interpreted as the rotation period of the star. (Messina et al. (2003) suspect the actual rotation period may be half that: 7.9 days.[14]) It has an active chromosphere[1] and is a source for X-ray emission.[15]

The star is around a billion years old with a projected rotational velocity of 3.8 km/s.[7] It has slightly above solar metallicity − the term astronomers use for the relative abundance of elements other than hydrogen and helium. The mass of the star is 8% greater than the Sun,[7] but it has 93% of the Sun's radius.[8] It is radiating 80% of the luminosity of the Sun from its photosphere at an effective temperature of 5649 K.[8] An infrared excess indicates a cold debris disk is orbiting the star at a distance of 17.48 AU with a mean temperature of 60 K. The disk has an estimated mass of 5.86×10−6 M🜨.[9]


References


  1. Strassmeier, K. G.; et al. (December 1997), "Photospheric and chromospheric activity of the bright and single G5 dwarf HR 4864 = HD 111395", Information Bulletin on Variable Stars, 4538: 1, Bibcode:1997IBVS.4538....1S.
  2. 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. 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. Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
  5. 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. Soubiran, C.; et al. (April 2013), "The catalogue of radial velocity standard stars for Gaia. I. Pre-launch release", Astronomy & Astrophysics, 552: 11, arXiv:1302.1905, Bibcode:2013A&A...552A..64S, doi:10.1051/0004-6361/201220927, S2CID 56094559, A64
  7. McCarthy, Kyle; Wilhelm, Ronald J. (October 2014), "Characterizing the AB Doradus Moving Group via High-resolution Spectroscopy and Kinematic Traceback", The Astronomical Journal, 148 (4): 13, arXiv:1407.1076, Bibcode:2014AJ....148...70M, doi:10.1088/0004-6256/148/4/70, S2CID 119296096, 70.
  8. 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.
  9. Gáspár, András; et al. (2016), "The Correlation between Metallicity and Debris Disk Mass", The Astrophysical Journal, 826 (2): 171, arXiv:1604.07403, Bibcode:2016ApJ...826..171G, doi:10.3847/0004-637X/826/2/171, S2CID 119241004.
  10. Vican, Laura (June 2012), "Age Determination for 346 Nearby Stars in the Herschel DEBRIS Survey", The Astronomical Journal, 143 (6): 135, arXiv:1203.1966, Bibcode:2012AJ....143..135V, doi:10.1088/0004-6256/143/6/135, S2CID 118539505.
  11. "HD 111395". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-11-28.
  12. Fuhrmann, K.; et al. (2017), "Multiplicity among Solar-type Stars", The Astrophysical Journal, 836 (1): 139, Bibcode:2017ApJ...836..139F, doi:10.3847/1538-4357/836/1/139.
  13. Nakajima, Tadashi; Morino, Jun-Ichi (January 2012), "Potential Members of Stellar Kinematic Groups within 30 pc of the Sun", The Astronomical Journal, 143 (1): 2, Bibcode:2012AJ....143....2N, doi:10.1088/0004-6256/143/1/2.
  14. Messina, S.; et al. (November 2003), "Dependence of coronal X-ray emission on spot-induced brightness variations in cool main sequence stars", Astronomy and Astrophysics, 410 (2): 671–684, Bibcode:2003A&A...410..671M, doi:10.1051/0004-6361:20031203.
  15. Greiner, J.; Richter, G. A. (March 2015), "Optical counterparts of ROSAT X-ray sources in two selected fields at low vs. high Galactic latitudes", Astronomy & Astrophysics, 575: 67, arXiv:1408.5529, Bibcode:2015A&A...575A..42G, doi:10.1051/0004-6361/201322844, S2CID 59501196, A42.

На других языках

- [en] HD 111395

[es] LW Comae Berenices

LW Comae Berenices (LW Com / HD 111395 / HR 4864)[1] es una estrella en la constelación de Cabellera de Berenice de magnitud aparente +6,31. Se encuentra a 57 años luz de distancia del Sistema Solar.

[ru] LW Волос Вероники

LW Волос Вероники (лат. LW Comae Berenices), HD 111395 — одиночная переменная звезда в созвездии Волосы Вероники на расстоянии приблизительно 56 световых лет (около 17,1 парсека) от Солнца. Видимая звёздная величина звезды — от +6,41m до +6,31m[9]. Возраст звезды определён как около 4,94 млрд лет[7].


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