The Plasquette star , also known as the HR 2422 or V640 Unicorn , is a spectrally double star in the constellation Unicorn . Located at a distance of more than 5000 St. years [1] from the sun .
| Plascetta Star AB | |||
|---|---|---|---|
| Double star | |||
| Research history | |||
| Discoverer | Plasquette, John Stanley | ||
| opening date | 1922 | ||
| Observational data ( Age J2000.0 ) | |||
| Right ascension | |||
| Declination | |||
| Distance | 5245 St. years [1] | ||
| Visible magnitude ( V ) | 6.06 [2] | ||
| Constellation | Unicorn | ||
| Astrometry | |||
| Radial velocity ( R v ) | +24.5 [3] km / s | ||
| Own movement (μ) | RA: –2.73 [5] Dec: +0.31 [5] | ||
| Parallax (π) | 0.62 ± 0.001 mas | ||
| Specifications | |||
| Spectral class | O8 III / I + O7.5 III [6] | ||
| Color Index ( B - V ) | +0.05 [2] | ||
| Color Index ( U - B ) | –0.88 [2] | ||
| physical characteristics | |||
| Weight | 54/56 M ☉ | ||
| Temperature | 32000 ± 1000/33000 ± 1000 K | ||
| |||
| Database Information | |||
| SIMBAD | data | ||
| The star has 2 components Their parameters are presented below: | |||
This is one of the most massive binary stars discovered, with a total mass of about 100 solar masses [6] . For a long time it was considered the most massive binary system [8] . However, detailed studies of Eta Kiel in 1996–2005 showed that this star with a mass of 150 solar, previously considered single, is a binary system [9] .
The system is named after John Stanley Plaskett , a Canadian astronomer who, in 1922, together with his son, Harry Hemley Plaskett, showed that the system is double, and also for the first time measured the circulation period and the mass of its components.
The pair has a total apparent magnitude of 6.05 m .
The orbital period of rotation of the pair is 14.39625 ± 0.00095 days [6] . The second component of the system rotates very rapidly around the axis with a radial speed of 300 km / s [8] and, due to this, should have the form of a strongly flattened ellipsoid [6] .
Notes
- ↑ 1 2 Megier, A .; Strobel, A .; Galazutdinov, GA & Krełowski, J. (November 2009), " The interstellar Ca II distance scale ", Astronomy and Astrophysics T. 507 (2): 833–840 , DOI 10.1051 / 0004-6361 / 20079144
- ↑ 1 2 3 Johnson, HL; Iriarte, B .; Mitchell, RI; Wisniewskj, WZ UBVRIJKL photometry of the bright stars (Eng.) // Communications of the Lunar and Planetary Laboratory . - University of Arizona Press , 1966. - Vol. 4 , no. 99 . - .
- ↑ Wilson, Ralph Elmer. General Catalog of Stellar Radial Velocities. - Washington: Carnegie Institution of Washington, 1953.
- ↑ 1 2 3 4 Gaia Data Release 2 - 2018.
- ↑ 1 2 van Leeuwen, F. Validation of the new Hipparcos reduction // Astronomy and Astrophysics . - EDP Sciences 2007 .-- November ( vol. 474 , no. 2 ). - P. 653-664 . - DOI : 10.1051 / 0004-6361: 20078357 . - . - arXiv : 0708.1752 .
- ↑ 1 2 3 4 5 6 7 8 9 10 11 12 Linder, N .; Rauw, G .; Martins, F. & Sana, H. (October 2008), " High-resolution optical spectroscopy of Plaskett's star ", Astronomy and Astrophysics T. 489 (2): 713–723 , DOI 10.1051 / 0004-6361: 200810003
- ↑ PLASKETT STAR - Double or multiple star , Center de Données astronomiques de Strasbourg , < http://simbad.u-strasbg.fr/simbad/sim-id?Ident=PLASKETT+STAR > . Retrieved January 3, 2012.
- ↑ 1 2 3 4 Mahy, L .; Gosset, E .; Baudin, F. & Rauw, G. (January 2011), " Plaskett's star: analysis of the CoRoT photometric data ", Astronomy and Astrophysics T. 525: A101 , DOI 10.1051 / 0004-6361 / 201014777
- ↑ Iping, Rosina C .; Sonneborn, George; Gull, Theodore R. & Massa, D. John (November 2005), " Detection of a Hot Binary Companion of η Carinae ", The Astrophysical Journal T. 633 (1): L37-L40 , DOI 10.1086 / 498268