Theta1 Microscopii

From Wikipedia, the free encyclopedia
Jump to: navigation, search
θ1 Microscopii
Microscopium constellation map.svg
link=Theta1 Microscopii

Location of θ1 Microscopii (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Microscopium
Right ascension 21h 20m 45.63900s[1]
Declination −40° 48′ 34.0512″[1]
Apparent magnitude (V) 4.82[2]
Spectral type A7VpSrCrEu[3]
U−B color index -0.07[2]
B−V color index +0.02[2]
Radial velocity (Rv) +2.30[4] km/s
Proper motion (μ) RA: +71.92[1] mas/yr
Dec.: +20.38[1] mas/yr
Parallax (π) 16.54 ± 1.19[1] mas
Distance 200 ± 10 ly
(60 ± 4 pc)
Absolute magnitude (MV) 1.03[5]
Mass 2.27[6] M
Radius 2.2[6] R
Luminosity 36.64[5] L
Surface gravity (log g) 4.31[7] cgs
Temperature 11,328[7] K
Metallicity [Fe/H] 0.00[8] dex
Rotational velocity (v sin i) 43[7] km/s
Other designations
CD-41 14475, FK5 802, GC 29854, HIP 105382, HR 8151, HD 203006, SAO 230644
Database references

Theta1 Microscopii (θ1 Mic) is a class A7 main sequence star in the constellation Microscopium. Its apparent magnitude is 4.82[2] and it is approximately 197 light years away based on parallax.[1]

It is reported as an α² CVn variable with a period of 2.125 days and a magnitude ranging from 4.77 to 4.87,[9] as well as a chemically peculiar star with strong metallic lines in its spectrum.[3][5]


  1. ^ a b c d e f Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653. Bibcode:2007A&A...474..653V. arXiv:0708.1752Freely accessible. doi:10.1051/0004-6361:20078357.  Vizier catalog entry
  2. ^ a b c d Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D. 
  3. ^ a b Abt, Helmut A.; Morrell, Nidia I. (1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". Astrophysical Journal Supplement v.99. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182. 
  4. ^ Wilson, R. E. (1953). General Catalogue of Stellar Radial Velocities. Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W. LCCN 54001336. 
  5. ^ a b c Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. Bibcode:2012AstL...38..331A. arXiv:1108.4971Freely accessible. doi:10.1134/S1063773712050015.  Vizier catalog entry
  6. ^ a b Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555. Bibcode:1999A&A...352..555A. arXiv:astro-ph/9911002Freely accessible.  Vizier catalog entry
  7. ^ a b c David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. Bibcode:2015ApJ...804..146D. arXiv:1501.03154Freely accessible. doi:10.1088/0004-637X/804/2/146.  Vizier catalog entry
  8. ^ Gontcharov, G. A. (2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771. Bibcode:2012AstL...38..771G. arXiv:1606.08814Freely accessible. doi:10.1134/S1063773712120031.  Vizier catalog entry
  9. ^ Watson, C. L. (2006). "The International Variable Star Index (VSX)". The Society for Astronomical Sciences 25th Annual Symposium on Telescope Science. Held May 23-25. 25: 47. Bibcode:2006SASS...25...47W.