Stellar and circumstellar activity of the Be star omega CMa. I. Line and continuum emission in 1996-2002

Details Stellar and circumstellar activity of the Be star omega CMa. I. Line and continuum emission in 1996-2002 Stellar and circumstellar activity of the Be star omega CMa. I. Line and continuum emission in 1996-2002

Apr 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003a%26a...402..253s&link_type=abstract

Astronomy and Astrophysics, v.402, p.253-265 (2003)

Astronomy and Astrophysics

Astrophysics

17

Stars: Activity, Stars: Circumstellar Matter, Stars: Emission-Line, Be, Stars: Individual: Omega 28 Cma

Scientific paper

Echelle spectroscopy and mostly unaided-eye photometry of the southern Be star omega CMa were obtained in the period 1996-2003. The monitoring is bracketed by two brightenings by 0.4m-0.5m. The results of a literature search suggest that such phases occur about once a decade and have various commonalities. Along with these photometric events goes enhanced line emission. This is due to an increased total mass of the disk as well as to a change in its density profile. The models by Poeckert & Marlborough (\cite{1978ApJS...38..229P}, \cite{1979ApJ...233..259P}) imply that the enhanced continuum flux originates from the inner disk. Higher-order Balmer line emission is correlated with brightness. The increase in Hα is retarded by some months, possibly indicating a time delay in filling up and ionizing the outer disk. In the (U-B) vs. (B-V) colour diagram and the D54 vs. D34 Balmer decrement diagram the path from the ground to the bright state is distinct from the return path. This could result from the bulk of the disk matter being in the outer (inner) disk during the photometric ground (high) state, while the two transitions between the two states are both due to changes progressing radially outward. Some mu Cen-like outbursts (Rivinius et al. \cite{1998A&A...333..125R}) seem to occur in all phases. It is conceivable that the build-up of the inner disk is caused by more frequent or more effective outbursts. During the photometric bright state various other phenomena gain in prominence and suggest this to be a phase of increased activity. Of particular interest, but possibly only apparently related to this phase, are absorption components at redshifts well beyond the range covered by the combination of rotation and nonradial pulsation.
Based on observations collected at the European Southern Observatory at La Silla, Chile, ESO (proposal nos. 55.D-0502, 56.D-0381, 58.D-0697, 62.H-0319, 64.H-0548).

Affiliated with

Also associated with

No associations

Rating

Stellar and circumstellar activity of the Be star omega CMa. I. Line and continuum emission in 1996-2002 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 Stellar and circumstellar activity of the Be star omega CMa. I. Line and continuum emission in 1996-2002, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stellar and circumstellar activity of the Be star omega CMa. I. Line and continuum emission in 1996-2002 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-918626