Multiwavelength observations of nova LMC 1991 during pre-maximum

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

1

Scientific paper

Nova LMC 1991 (hereafter LMC 91) was the intrisically most luminous nova, and one of the fastest (t_3 = 6 +/- 1 days), yet observed. It was discovered on 18.3 April, 1991 (Liller, IAUC 5244) at m_v = 12, although UK Schmidt J (4000 - 5400 Angstroms) plates show that LMC 91 steadily increased in brightness from a possible pre-outburst magnitude of mV ~ 20.5 in early April. It reached m_V(max) ~ 9 on 24 April. The slow rise to maximum was very unusual, showing behavior more closely resembling a slow nova. The combination of the rapid discovery announcement and a very slow pre-maximum rise permitted many IUE and optical observations. The 20.0 April optical spectrum showed strong hydrogen and iron multiplet P Cygni lines; most other novae with pre-maximum spectra (with the exception of DQ Her) show only blue shifted absorption lines. The IUE spectrum on that date, the earliest UV spectrum ever obtained of a nova in outburst, showed the bulk of the flux being emitted below 2300 Angstroms. By 22.8 April, the UV spectral peak had shifted to lambda > 2500 Angstroms and the spectrum was similar to the pre-maximum spectra seen in Nova Cyg 1992. The best agreement between the observations and the synthetic spectra (calculated with spherical, NLTE, line-blanketed PHOENIX model atmospheres) requires a metallicity Z = 0.1Zsun. This is significantly lower metallicity than the canonical LMC value of 1/3 used to successfully model nova LMC 1988 #1 (Schwarz et al. 1998, MNRAS, in press). The extreme brightness and low metallicity of LMC 91 may confirm recent hydrodynamic calculations that metallicity is inversely correlates with luminosity if mixing occurs during the thermonuclear runaway (Starrfield et al. 1998, MNRAS, 296, 502).

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Multiwavelength observations of nova LMC 1991 during pre-maximum does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Multiwavelength observations of nova LMC 1991 during pre-maximum, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multiwavelength observations of nova LMC 1991 during pre-maximum will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-997508

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.