ι Microscopii, Latinized as Iota Microscopii, is a suspected astrometric binary[10] star system in the southern constellation of Microscopium, near the southern constellation border with Indus. It is visible to the naked eye as a dim, yellow-white hued point of light with an apparent visual magnitude of 5.11.[2] This object is 121 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −14 km/s.[1]
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Microscopium |
| Right ascension | 20h 48m 29.14779s[1] |
| Declination | −43° 59′ 18.6369″[1] |
| Apparent magnitude (V) | 5.11[2] |
| Characteristics | |
| Spectral type | F2V[3] |
| U−B color index | +0.04[4] |
| B−V color index | +0.35[5] |
| Astrometry | |
| Radial velocity (Rv) | −14.35±0.69 km/s |
| Proper motion (μ) | RA: +178.881[1] mas/yr Dec.: −112.407[1] mas/yr |
| Parallax (π) | 26.9052 ± 0.1782 mas[1] |
| Distance | 121.2 ± 0.8 ly (37.2 ± 0.2 pc) |
| Absolute magnitude (MV) | 2.05[2] |
| Details | |
| Mass | 1.42[6] M☉ |
| Radius | 2.4[7] R☉ |
| Luminosity | 12.65[2] L☉ |
| Surface gravity (log g) | 3.90±0.14[6] cgs |
| Temperature | 6,997±238[6] K |
| Metallicity [Fe/H] | −0.03[2] dex |
| Rotational velocity (v sin i) | 115[8] km/s |
| Age | 1.094[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The visible component is an ordinary F-type main-sequence star with a stellar classification of F2V,[3] which indicates it is generating energy through core hydrogen fusion. It is around a billion years old with 1.4 times the mass of the Sun[6] and 2.4[7] times the Sun's radius. The star is radiating 13[2] times the luminosity of the Sun from its photosphere at an effective temperature of 6,997 K.[6] It has a high rate of spin with a projected rotational velocity of 115 km/s, which is giving the star an equatorial bulge that is 6% larger than the polar radius.[8]
Iota Microscopii has one visual companion, first observed in 1932, with a separation of 4.3" and a visual magnitude of 15.5.[11]
References
edit- ^ a b c d e f 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.
- ^ a b c d e f 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. Vizier catalog entry
- ^ a b Houk, Nancy (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 2. Ann Arbor: Department of Astronomy, University of Michigan. Bibcode:1978mcts.book.....H.
- ^ Mermilliod, J. C. (2006). "VizieR Online Data Catalog: Homogeneous Means in the UBV System (Mermilliod 1991)". VizieR On-line Data Catalog: II/168. Originally Published in: Institut d'Astronomie. 2168. Bibcode:2006yCat.2168....0M.Vizier catalog entry
- ^ Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42 (2): 443. Bibcode:2014JAVSO..42..443M.Vizier catalog entry
- ^ a b c d e f 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. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. S2CID 33401607. Vizier catalog entry
- ^ 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: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. Vizier catalog entry
- ^ a b van Belle, Gerard T. (March 2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review, 20 (1): 51, arXiv:1204.2572, Bibcode:2012A&ARv..20...51V, doi:10.1007/s00159-012-0051-2, S2CID 119273474
- ^ "iot Mic". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-04.
- ^ 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.
- ^ 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. Vizier catalog entry