AG Carinae

From Wikipedia, the free encyclopedia
Jump to: navigation, search
AG Carinae
AG Car
AG Car (Hubble Space Telescope image)
Observation data
Epoch J2000      Equinox J2000
Constellation Carina
Right ascension 10h 56m 11.57699s[1]
Declination −60° 27′ 12.8056″[1]
Apparent magnitude (V) 6.96[2]
Characteristics
Spectral type LBV
U−B color index –0.58[2]
B−V color index +0.61[2]
Variable type LBV[3]
Astrometry
Proper motion (μ) RA: −5.89[1] mas/yr
Dec.: +2.45[1] mas/yr
Distance 4,364[4] ly
(1,338 pc)
Details
Mass 70[3] M
Radius 62[3] R
Luminosity 1.5 × 106[3] L
Temperature 17,000–22,800[3] K
Rotation 13 ± 2[3]
Rotational velocity (v sin i) 220 ± 50[3] km/s
Other designations
CD–59 3430, HD 94910, HIP 53461, SAO 251185.

AG Carinae (AG Car) is a star in the constellation Carina. It is classified as a luminous blue variable and is one of the most luminous stars in the Milky Way. The large distance (20,000 light-years) and intervening dust mean that the star is not visible to the naked eye; its apparent brightness varies irregularly between 5.7m and 9.0m. The star is surrounded by a large planetary nebula, formed by material expulsed from the star by its powerful stellar wind. The star is apparently in a transitional phase between a massive class O blue supergiant and a Wolf-Rayet star, and the spectral type varies between WN11 at visual minimum and an early A hypergiant at maximum.

References[edit]

  1. ^ a b c d van Leeuwen, F. (November 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 
  2. ^ a b c Nicolet, B. (1978). "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System". Astronomy and Astrophysics Supplement Series 34: 1–49. Bibcode:1978A&AS...34....1N. 
  3. ^ a b c d e f g Groh, J. H.; Hillier, D. J.; Damineli, A. (July 2011), "On the Nature of the Prototype Luminous Blue Variable AG Carinae. II. Witnessing a Massive Star Evolving Close to the Eddington and Bistability Limits", The Astrophysical Journal 736 (1), arXiv:1105.0814, Bibcode:2011ApJ...736...46G, doi:10.1088/0004-637X/736/1/46 
  4. ^ Stanghellini, Letizia; Shaw, Richard A.; Villaver, Eva (December 2008), "The Magellanic Cloud Calibration of the Galactic Planetary Nebula Distance Scale", The Astrophysical Journal 689 (1): 194–202, arXiv:0807.1129, Bibcode:2008ApJ...689..194S, doi:10.1086/592395 

External links[edit]