Line Profiles of Cepheid Variables - Projection Factors and Metallic Cline Asymmetries

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

26

Line: Profiles - Stars: Atmospheres - Stars: Fundamental Parameters - Cepheids

Scientific paper

A grid of synthetic line profiles incorporating a new treatment of macroturbulence is calculated for a Cepheid atmosphere in radial motion. Projection factors are determined to be up to 10 per cent higher than previous calculations.
A programme of high-resolution spectroscopic observations of Cepheids has been carried out at Mt John University Observatory for several years. Radial velocities and asymmetries have been measured for selected metallic lines and the asymmetries compared with those of the synthetic profiles.
The line profiles from the observations show a larger asymmetry than the synthetic profiles at phases of inward pulsational velocity. The asymmetry at phases of outward velocity is smaller and in agreement with the synthetic profiles for some Cepheids. For others, however, the asymmetry at phases of outward pulsation is in the direction expected for inward motion. The discrepant line asymmetries cannot be due to geometric projection of a single pulsational velocity, an assumption inherent in calculations of radii and distances by the Baade-Wesselink method.

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

Line Profiles of Cepheid Variables - Projection Factors and Metallic Cline Asymmetries 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 Line Profiles of Cepheid Variables - Projection Factors and Metallic Cline Asymmetries, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Line Profiles of Cepheid Variables - Projection Factors and Metallic Cline Asymmetries will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1260145

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