Eta Microscopii

Eta Microscopii is a topic that has captured the attention of people around the world. Since its emergence, it has generated great interest and debate in different areas, whether in politics, culture, science or society in general. This topic has been the subject of research and analysis by experts and academics, with the aim of understanding its impact and implications. Furthermore, it has aroused the interest of the general population, generating conversations and reflections on different platforms and discussion spaces. In this article we will explore Eta Microscopii in detail, analyzing its most relevant aspects and offering a broad and varied perspective on this topic.

Eta Microscopii
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Microscopium
Right ascension 21h 06m 25.51950s[1]
Declination −41° 23′ 09.4805″[1]
Apparent magnitude (V) 5.53[2]
Characteristics
Spectral type K3 III[3]
U−B color index +1.50[2]
B−V color index +1.35[2]
Astrometry
Radial velocity (Rv)+22.29±0.13[1] km/s
Proper motion (μ) RA: +28.760[1] mas/yr
Dec.: −11.548[1] mas/yr
Parallax (π)3.5657±0.1149 mas[1]
Distance910 ± 30 ly
(280 ± 9 pc)
Absolute magnitude (MV)−1.13[4]
Details
Mass1.2[5] M☉
Radius47.41+0.95
−5.67[1] R☉
Luminosity735±28[1] L☉
Surface gravity (log g)1.1[5] cgs
Temperature4,365+287
−43[1] K
Metallicity −0.31[5] dex
Other designations
η Mic, CD−41°14379, FK5 3684, GC 29461, HD 200702, HIP 104177, HR 8069, SAO 230523[6]
Database references
SIMBADdata

Eta Microscopii, Latinised as η Microscopii, is a solitary[7] star in the constellation Microscopium. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.53.[2] The star is located around 910 light-years distant from the Sun based on parallax, and is drifting further away with a radial velocity of +22 km/s.[1]

This is an aging giant star with a stellar classification of K3 III,[3] indicating that it has exhausted the supply of hydrogen at its core then cooled and expanded. At present it has around 47[1] times the girth of the Sun. The star is radiating 735 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,365 K.[1]

Multiple star catalogues list two optical companions.[8] Two arc-minutes away, the 8th magnitude HD 200733 is a main sequence star much closer to Earth than η Microscopii.[9] A 14th-magnitude star one arc-minute from η Microscopii is a background object.[10]

References

  1. ^ a b c d e f g h i j k l 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.
  2. ^ a b c d Drilling, J. S. (February 1973), "Photoelectric UBV photometry of late-type stars in two regions at high galactic latitude", Astronomical Journal, 78: 44–46, Bibcode:1973AJ.....78...44D, doi:10.1086/111370.
  3. ^ a b Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
  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.
  5. ^ a b c Anders, F.; Khalatyan, A.; Chiappini, C.; Queiroz, A. B.; Santiago, B. X.; Jordi, C.; Girardi, L.; Brown, A. G. A.; Matijevič, G.; Monari, G.; Cantat-Gaudin, T.; Weiler, M.; Khan, S.; Miglio, A.; Carrillo, I.; Romero-Gómez, M.; Minchev, I.; De Jong, R. S.; Antoja, T.; Ramos, P.; Steinmetz, M.; Enke, H. (2019), "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18", Astronomy and Astrophysics, 628: A94, arXiv:1904.11302, Bibcode:2019A&A...628A..94A, doi:10.1051/0004-6361/201935765, S2CID 131780028.
  6. ^ "eta Mic", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2017-08-12.
  7. ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  8. ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001), "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
  9. ^ 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.
  10. ^ 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.