Computer Science
Scientific paper
Jul 1993
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993hst..prop.4634a&link_type=abstract
HST Proposal ID #4634
Computer Science
Hst Proposal Id #4634
Scientific paper
ZZ Ceti stars are variable white dwarfs of spectral type DA. The theoretically predicted instability strip depends on several uncertain assumptions, most importantly the efficiency of convective energy transport and the detailed structure of the outer stellar layers (chemical stratification, thickness of hydrogen layers). Empirical determinations are so far not as accurate as desirable for a comparison, because: (i) the Balmer lines in the optical region reach maximum strengths with in the instability strip and therefore vary only little with temperature, and (ii) the use of the ultraviolet spectrum, which is dominated by the line wing of Lyman alpha with quasimolecular satellites at 1400 and 1600 A has been hampered by the lack of an adequate theoretical description of the line shape. This theory has now been developed by one of us (N.Allard) and incorporated into stellar atmosphere programs, allowing us to determine effective temperatures in this range with an accuracy of 200 K. In Cycle 2 we will obtain observations of the apparently hottest ZZ Ceti object (G117-B15A). In this project we want to observe G255-2 - possibly the coolest ZZ Ceti - to get a good estimate for the red edge of the instability region.
No associations
LandOfFree
The Red Edge of the ZZ Ceti Instability STRIP:CYCLE3 Medium 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 The Red Edge of the ZZ Ceti Instability STRIP:CYCLE3 Medium, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Red Edge of the ZZ Ceti Instability STRIP:CYCLE3 Medium will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1071516