Syrma

Iota Virginis

Iota Virginis

Binary star system in the constellation Virgo


Iota Virginis (ι Virginis, abbreviated Iota Vir, ι Vir) is a binary star in the constellation of Virgo. Its apparent magnitude is 4.08.[2] Based on its parallax, it is assumed to be relatively nearby, at 72.5 light-years (22.2 parsecs).[1]

Quick Facts Constellation, Right ascension ...

Its two components are designated Iota Virginis A (officially named Syrma /ˈsɜːrmə/,[8] the traditional name for the system)[9] and B.

Nomenclature

ι Virginis (Latinised to Iota Virginis) is the system's Bayer designation. The designations of the two components as Iota Virginis A and B derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).[10]

It bore the traditional name Syrma, derived from the Arabic سرما (تطريز sirmā "train (of a garment)".[11] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[12][13] to catalogue and standardize proper names for stars. The WGSN approved the name Syrma for Iota Virginis on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.[9] For such names relating to members of multiple star systems, and where a component letter (from e.g. Washington Double Star Catalog) is not explicitly listed, the WGSN says that the name should be understood to be attributed to the brightest component by visual brightness.[14]

In China, 亢宿 (Kàng Xiù), meaning Neck, refers to an asterism consisting of this star, Kappa Virginis, Phi Virginis and Lambda Virginis.[15] Consequently, Iota Virginis itself is known as 亢宿二 (Kàngxiùèr, English: the Second Star of Neck).

Properties

Iota Virginis is an astrometric binary. The secondary regularly perturbs the primary, causing the latter to wobble around its barycenter.[3] A preliminary orbit with a period of 55 years has been calculated.[3]

Iota Virginis A is a yellow-colored star with a spectral class of F7IV-V. This star has 1.5 times the mass of the Sun, with a projected rotational velocity of 16 km s−1.[3] It is radiating 8.7 times the luminosity of the Sun[6] from its outer atmosphere at an effective temperature of 6,282 K.[7] The radius is about 2.5 times that of the Sun.[6]

Iota Virginis B has not been directly detected, but based on its mass (0.6 M) it may be a main-sequence star or a white dwarf.[3] That star is also responsible for the drifting radial velocity of the primary.[16]

In 2011, it was noticed that the faint K-type main-sequence star HD 125354 had a similar proper motion throughout space, and was likely physically associated.[17] Another 2015 paper supported this hypothesis. The star, which is located 1.2 ly (0.37 pc) away from Iota Virginis, also has a similar distance from the Sun, within the margin of error. It itself is a close binary with another star separated 0.33 from the main star.[18]


References

  1. van Leeuwen, F.; et al. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
  2. Gontcharov, G.A.; Kiyaeva, O.V. (2010). "Photocentric orbits from a direct combination of ground-based astrometry with Hipparcos II. Preliminary orbits for six astrometric binaries". New Astronomy. 15 (3): 324–331. arXiv:1606.08182. Bibcode:2010NewA...15..324G. doi:10.1016/j.newast.2009.09.006. S2CID 119252073.
  3. Maldonado, J.; Martínez-Arnáiz, R. M.; Eiroa, C.; Montes, D.; Montesinos, B. (2010). "A spectroscopy study of nearby late-type stars, possible members of stellar kinematic groups". Astronomy and Astrophysics. 521: A12. arXiv:1007.1132. Bibcode:2010A&A...521A..12M. doi:10.1051/0004-6361/201014948. S2CID 119209183.
  4. Malagnini, M. L.; Morossi, C. (November 1990). "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars". Astronomy and Astrophysics Supplement Series. 85 (3): 1015–1019. Bibcode:1990A&AS...85.1015M.
  5. Mallik, Sushma V. (December 1999). "Lithium abundance and mass". Astronomy and Astrophysics. 352: 495–507. Bibcode:1999A&A...352..495M.
  6. "Naming Stars". IAU.org. Retrieved 16 December 2017.
  7. Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 [astro-ph.SR].
  8. Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York, NY: Dover Publications Inc. pp. 472. ISBN 0-486-21079-0.
  9. IAU Formally Approves 227 Star Names, International Astronomical Union, retrieved 24 November 2016.
  10. Borgniet, S.; Lagrange, A.-M.; Meunier, N.; Galland, F. (2017). "Extrasolar planets and brown dwarfs around AF-type stars". Astronomy & Astrophysics. 599: A57. arXiv:1608.08257. Bibcode:2017A&A...599A..57B. doi:10.1051/0004-6361/201628805. S2CID 118723455.
  11. Shaya, Ed J.; Olling, Rob P. (January 2011). "Very Wide Binaries and Other Comoving Stellar Companions: A Bayesian Analysis of the Hipparcos Catalogue". The Astrophysical Journal Supplement. 192 (1): 2. arXiv:1007.0425. Bibcode:2011ApJS..192....2S. doi:10.1088/0067-0049/192/1/2. S2CID 119226823.
  12. Fuhrmann, K.; Chini, R. (2015). "Multiplicity Among F-Type Stars. II". The Astrophysical Journal. 809 (1): 107. Bibcode:2015ApJ...809..107F. doi:10.1088/0004-637X/809/1/107.



Share this article:

This article uses material from the Wikipedia article Syrma, and is written by contributors. Text is available under a CC BY-SA 4.0 International License; additional terms may apply. Images, videos and audio are available under their respective licenses.