Astronomy:2MASS J20360829−3607115
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Microscopium |
| Right ascension | 20h 36m 08.3089s[1] |
| Declination | −36° 07′ 11.5098″[1] |
| Apparent magnitude (V) | 11.55 - 11.85[2] |
| Characteristics | |
| Spectral type | M3 Ve[3] |
| B−V color index | +1.91[4] |
| R−I color index | +2.10[5][6] |
| Variable type | BY Drac[2] |
| Astrometry | |
| Radial velocity (Rv) | 14.92±9.20[7] km/s |
| Proper motion (μ) | RA: +6.221[1] mas/yr Dec.: +39.841[1] mas/yr |
| Parallax (π) | 59.2137 ± 0.0241[1] mas |
| Distance | 55.08 ± 0.02 ly (16.888 ± 0.007 pc) |
| Details | |
| Mass | 0.42[8] M☉ |
| Radius | 0.46[9] R☉ |
| Luminosity | 0.032[8] L☉ |
| Surface gravity (log g) | 5.00[9] cgs |
| Temperature | 3,537[8] K |
| Rotational velocity (v sin i) | 9.6±1.2[3] km/s |
| Age | 12[10] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
2MASS J20360829−3607115 or DH Microscopii is a solitary[12] star in the constellation Microscopium. It has an average apparent magnitude of 11.56,[4] making it readily visible in telescopes but not to the naked eye. The object is relatively close at a distance of 55 light years[1] but is receding with a heliocentric radial velocity of 14.9 km/s.[7]
The object was originally catalogized as an active galaxy nucleus candidate.[13] However, observation afterwards revealed that it was instead a red dwarf with a stellar classification of M3 Ve. This class indicates that DH Mircoscopii is a M-type main-sequence star with emission lines in its spectrum. It has 42% the mass of the Sun[8] and 46% the radius of the Sun.[9] Despite being half the size of the Sun, DH Microscopii only has a luminosity 3.2% that of the Sun and has an effective temperature of 3,537 K.[8] This gives the star a red hue when viewed through a telescope. DH Micro is a young star with an age of 12 million years[10] and spins with a projected rotational velocity of 9.6 km/s.[3]
DH Microscopii is a BY Draconis variable[2] — young G to M type stars whose starspot activity cause variations in their brigtness. It flucates by 0.3 magnitudes within 2 days.[14]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 Samus’, N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports 61 (1): 80–88. doi:10.1134/S1063772917010085. ISSN 1063-7729. Bibcode: 2017ARep...61...80S.
- ↑ 3.0 3.1 3.2 Torres, C. A. O.; Quast, G. R.; da Silva, L.; de la Reza, R.; Melo, C. H. F.; Sterzik, M. (12 September 2006). "Search for associations containing young stars (SACY)". Astronomy & Astrophysics 460 (3): 695–708. doi:10.1051/0004-6361:20065602. ISSN 0004-6361. Bibcode: 2006A&A...460..695T.
- ↑ 4.0 4.1 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. ISSN 0004-6361. Bibcode: 2000A&A...355L..27H.
- ↑ Zacharias, N.; Finch, C. T.; Girard, T. M.; Henden, A.; Bartlett, J. L.; Monet, D. G.; Zacharias, M. I. (14 January 2013). "The Fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)". The Astronomical Journal 145 (2): 44. doi:10.1088/0004-6256/145/2/44. ISSN 0004-6256. Bibcode: 2013AJ....145...44Z.
- ↑ Kiraga, M. (March 2012). "ASAS Photometry of ROSAT Sources. I. Periodic Variable Stars Coincident with Bright Sources from the ROSAT All Sky Survey". Acta Astronomica 62: 67–95. ISSN 0001-5237. Bibcode: 2012AcA....62...67K.
- ↑ 7.0 7.1 Steinmetz, Matthias et al. (27 July 2020). "The Sixth Data Release of the Radial Velocity Experiment (Rave). II. Stellar Atmospheric Parameters, Chemical Abundances, and Distances". The Astronomical Journal 160 (2): 83. doi:10.3847/1538-3881/ab9ab8. Bibcode: 2020AJ....160...83S.
- ↑ 8.0 8.1 8.2 8.3 8.4 Gaidos, E.; Mann, A. W.; Lépine, S.; Buccino, A.; James, D.; Ansdell, M.; Petrucci, R.; Mauas, P. et al. (4 August 2014). "Trumpeting M dwarfs with CONCH-SHELL: a catalogue of nearby cool host-stars for habitable exoplanets and life". Monthly Notices of the Royal Astronomical Society 443 (3): 2561–2578. doi:10.1093/mnras/stu1313. ISSN 0035-8711. Bibcode: 2014MNRAS.443.2561G.
- ↑ 9.0 9.1 9.2 Morrell, Sam; Naylor, Tim (13 August 2019). "Exploring the M-dwarf Luminosity–Temperature–Radius relationships using Gaia DR2". Monthly Notices of the Royal Astronomical Society 489 (2): 2615–2633. doi:10.1093/mnras/stz2242. ISSN 0035-8711. Bibcode: 2019MNRAS.489.2615M.
- ↑ 10.0 10.1 Žerjal, M.; Zwitter, T.; Matijevič, G.; Grebel, E. K.; Kordopatis, G.; Munari, U.; Seabroke, G.; Steinmetz, M. et al. (18 January 2017). "Chromospherically Active Stars in the RAVE Survey. II. Young Dwarfs in the Solar Neighborhood". The Astrophysical Journal 835 (1): 61. doi:10.3847/1538-4357/835/1/61. Bibcode: 2017ApJ...835...61Z.
- ↑ "DH Microscopii". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=DH+Microscopii.
- ↑ Winters, Jennifer G.; Henry, Todd J.; Jao, Wei-Chun; Subasavage, John P.; Chatelain, Joseph P.; Slatten, Ken; Riedel, Adric R.; Silverstein, Michele L. et al. (7 May 2019). "The Solar Neighborhood. XLV. The Stellar Multiplicity Rate of M Dwarfs Within 25 pc". The Astronomical Journal 157 (6): 216. doi:10.3847/1538-3881/ab05dc. Bibcode: 2019AJ....157..216W.
- ↑ Fruscione, Antonella (March 1996). "X-Ray--selected Extreme-Ultraviolet Galaxies: Scraping the Bottom of the ``Invisible Barrel". The Astrophysical Journal 459: 509. doi:10.1086/176914. ISSN 0004-637X. Bibcode: 1996ApJ...459..509F.
- ↑ Watson, C. L.; Henden, A. A.; Price, A. (May 2006). "The International Variable Star Index (VSX)". Society for Astronomical Sciences Annual Symposium 25: 47. Bibcode: 2006SASS...25...47W.
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