HD 111395

Last updated
HD 111395
LWComLightCurve.png
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]
Distance 55.77 ± 0.03  ly
(17.098 ± 0.009  pc)
Absolute magnitude  (MV)5.15 [3]
Details
Mass 1.08±0.04 [7]   M☉
Radius 0.93±0.01 [8]   R☉
Luminosity 0.799±0.001 [8]   L☉
Surface gravity (log g)4.543±0.05 [7]   cgs
Temperature 5,649+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
Age 1.0 [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
SIMBAD data

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]

This object is a G-type main-sequence star with a stellar classification of G7V. [4] Klaus G. Strassmeier et al. announced their discovery that HD 111395 is a variable star, in 1997. [1] It was given its variable star designation in 2006. [14] 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. [15] ) It has an active chromosphere [1] and is a source for X-ray emission. [16]

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. 1 2 3 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. 1 2 3 4 5 6 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. 1 2 3 4 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. 1 2 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. 1 2 3 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. 1 2 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. 1 2 3 4 5 6 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. 1 2 3 4 5 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. 1 2 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. ↑ Kazarovets, E. V.; et al. (August 2006), "The 78th Name-List of Variable Stars" (PDF), Information Bulletin on Variable Stars, 5721: 1–45, Bibcode:2006IBVS.5721....1K , retrieved 8 February 2025.
  15. ↑ 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 .
  16. ↑ 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.
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