Home  
  The Nature of Eta Carinae  
History Before HST The Companion Star Spectroscopic Events The Sea Change Basic Parameters Astrometry Images and the Eta Car Environment Alternate Names
  HST & Eta Car  
Discoveries HST Treasury Project Technical Memos Software
  LBV, Hypergiants, and SN Impostors  
Giant Eruptions & Supernova Impostors Luminous Blue Variables Hypergiants
  Luminous Stars  
NGC2403 & M81 M31 & M33 M101
  Data Archive  
Documentation Spectra Images
  References  

Basic Parameters & Information

 

Summary of Basic Parameters

ParameterAccepted Value Reference
Distance 2.2 to 2.3 Kpc Allen & Hillier 1993, Davidson & Humphreys 1997, Meaburn 1999, Davidson et al 2001
Total Luminosity
(measured from thermal infrared)		 ~ 5x106 Lsun
MBol~ -12mag
~ 1049 ergs		 Westphal and Neugebauer 1969, Cox et al 1995
Zero Age Main Sequence Mass
from IR Luminosity		 >150 Msun Westphal and Neugebauer 1969, Cox et al 1995
Current Mass ~120 Msun Westphal and Neugebauer 1969, Cox et al 1995
Expected Main Sequence Lifetime~ 3 million years Westphal and Neugebauer 1969, Cox et al 1995
Current Mass Loss Rate10^-3 Msun/year Cox et al 1995, Davidson et al 1995, Hillier et al 2001
Surface Temperature15000 to 30000 K Hillier et al 2001
Radius0.4 to 0.9 AU Hillier et al 2001
Dynamical Timescale~2 weeks Hillier et al 2001
Thermal Timescale5 to 500 years
dependant on mass fraction considered		 Hillier et al 2001
Ejected CompositionHe & N rich Davidson et al 1982, 1986, Dufour 1989, Dufour et al 1999
Evolutionary Statenear or past end of core H burning Davidson et al 1982, 1986, Dufour 1989, Dufour et al 1999

The Great Eruption

Sustained LuminosityMBol~ -13
Sustained for several years		see History
Peak LuminosityMBol~ -14see History
Total Mass Ejected3 to 15 Msunsee History
Average Mass Loss Rate0.1 to 0.5 Msun/yearsee History

 

General References

Caution: The subject has more than its share of misunderstandings, and a lot of misleading or incorrect information has been published or appears on the internet. Even such a fundamental quantity as luminosity is a subtle and tricky problem. Aside from recent papers on specific sub-topics noted elsewhere in this site, for background information we currently recommend four general sources, and especially the many papers cited therein:

  • A very brief review which takes only a few minutes to read: K. Davidson, in Cosmic Explosions, AIP Conf. Proc. 522 (ed. S.S. Holt & W.W. Zhang, 2000), p. 421.
  • Essential pre-1997 references are noted in K. Davidson & R.M. Humphreys, Ann. Revs. Astron. Astrophys. 35, 1 (1997). Also contains explanations, comments, and a list of major unsolved problems.
  • Many novel developments appeared at a small but important meeting held after the 1997-98 spectroscopic event. The proceedings volume is Eta Carinae at the Millennium, ASP Conf. Ser. 179, ed. by J.A. Morse, R.M. Humphreys, & A. Damineli (1999).
  • The similar book from a later meeting, concentrating on spectroscopic studies, is Eta Carinae and Other Mysterious Stars: Hidden Opportunities of Emission-line Spectroscopy, ASP Conf. Ser. 242, ed. by T.R. Gull, S. Johansson, & K. Davidson (2001).