Asymmetries in the Spectral Lines of Evolved Halo Stars

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

7

Convection, Stars: Oscillations, Stars: Variables: Other, Supergiants, Techniques: Spectroscopic

Scientific paper

We do an initial reconnaissance of asymmetries of spectral lines in metal-poor field stars using high-resolution observations of four red horizontal-branch and 11 red giant branch stars taken with the coude spectrograph at the Canada-France-Hawaii Telescope. We find that (1) the shapes of the line bisectors for metal-poor stars hotter than 4100 K mimic the well-known C shape of bisectors for solar-metallicity stars on the cool side of the granulation boundary while (2) metal-poor stars cooler than 4100 K, or higher up the red giant branch than M V = 1.5, show bisectors with a reversed-C shape, similar to those for solar-metallicity stars on the hot side of the granulation boundary and similar to the reversed-C shape found in a previous study for the M-type supergiant Betelgeuse. The well-documented radial-velocity jitter of high-luminosity stars and the line bisector characteristics vary in concert up the red giant branch; both phenomena are probably signatures of large convection cells.
Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique de France, and the University of Hawaii.

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

Asymmetries in the Spectral Lines of Evolved Halo Stars 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 Asymmetries in the Spectral Lines of Evolved Halo Stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Asymmetries in the Spectral Lines of Evolved Halo Stars will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1427779

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