 A visual band light curve for LW Comae Berenices, adapted from Strassmeier et al. (1997) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Coma Berenices |
| Right ascension | 12 48 47.048 |
| Declination | +24° 50′ 24.82″ |
| Apparent magnitude (V) | 6.29 |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | G7V |
| B−V color index | 0.703±0.002 |
| Variable type | BY Dra |
| Astrometry | |
| Radial velocity (Rv) | −8.936±0.0064 km/s |
| Proper motion (μ) | RA: −334.908 mas/yr Dec.: −105.517 mas/yr |
| Parallax (π) | 58.4858 ± 0.0293 mas |
| Distance | 55.77 ± 0.03 ly (17.098 ± 0.009 pc) |
| Absolute magnitude (MV) | 5.15 |
| Details | |
| Mass | 1.08±0.04 M☉ |
| Radius | 0.93±0.01 R☉ |
| Luminosity | 0.799±0.001 L☉ |
| Surface gravity (log g) | 4.543±0.05 cgs |
| Temperature | 5,649+38 −17 K |
| Metallicity | 0.08±0.02 dex |
| Rotational velocity (v sin i) | 3.8±0.8 km/s |
| Age | 1.0 or 1.01−1.73 Gyr |
| Other designations | |
| LW Com, BD+25°2568, FK5 3021, GJ 486.1, HD 111395, HIP 62523, HR 4864, SAO 82511 | |
| Database references | |
| SIMBAD | data |
HD 111395 is a single, variable star in the northern constellation of Coma Berenices. It has the variable star designation LW Com, short for LW Comae Berenices; 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. Based upon parallax measurements, it is located at a distance of 55.8 light years from the Sun. The star is drifting closer with a radial velocity of −8.9 km/s. It is a member of the Eta Chamaeleontis stellar kinematic group.
This object is a G-type main-sequence star with a stellar classification of G7V. It is a BY Draconis variable that varies in brightness by about 0.10 magnitude over a period of 15.8 days, 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.) It has an active chromosphere and is a source for X-ray emission.
The star is around a billion years old with a projected rotational velocity of 3.8 km/s. 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, but it has 93% of the Sun's radius. It is radiating 80% of the luminosity of the Sun from its photosphere at an effective temperature of 5649 K. 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 M🜨.
References
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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
- ^ 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.
- ^ 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.
- ^ 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.
- 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.
- "HD 111395". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-11-28.
- 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.
- 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.
- 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.
- 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.
