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Asymmetries in the Spectral Lines of Evolved Halo Stars
We do an initial reconnaissance of asymmetries of spectral lines inmetal-poor field stars using high-resolution observations of four redhorizontal-branch and 11 red giant branch stars taken with the coudespectrograph at the Canada-France-Hawaii Telescope. We find that (1) theshapes of the line bisectors for metal-poor stars hotter than 4100 Kmimic the well-known C shape of bisectors for solar-metallicity stars onthe cool side of the granulation boundary while (2) metal-poor starscooler than 4100 K, or higher up the red giant branch than MV = –1.5, show bisectors with a reversed-C shape,similar to those for solar-metallicity stars on the hot side of thegranulation boundary and similar to the reversed-C shape found in aprevious study for the M-type supergiant Betelgeuse. The well-documentedradial-velocity jitter of high-luminosity stars and the line bisectorcharacteristics vary in concert up the red giant branch; both phenomenaare 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, theInstitut National des Sciences de l'Univers of the Centre National de laRecherche Scientifique de France, and the University of Hawaii.
| Spectral types for early-type stars observed by SKYLAB
MK spectral types are presented for 246 early-type stars observed withthe S-019 ultraviolet stellar astronomy experiment on Skylab. K-linetypes are also given where applicable, and various peculiar stars areidentified. The peculiar stars include five silicon stars, a shell star,a helium-rich star, a silicon-strontium star, a chromium-europium star,and two marginal metallic-line stars.
| New double stars (12th series) discovered at Nice
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975A&AS...20..379C&db_key=AST
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