Physics
Scientific paper
Jul 1996
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996hst..prop.6654w&link_type=abstract
HST Proposal ID #6654
Physics
Hst Proposal Id #6654 Hot Stars
Scientific paper
Any tentative explanation of the origin of the variousfamilies of white dwarf stars requires first a completeunderstanding of their basic physical properties (effectivetemperature, surface gravity, surface composition). In orderto refine the calibration of the effective temperature scaleof the hot, helium-line (DB) white dwarfs, we propose tosecure FOS/GHRS energy distributions in the 1200--3250Angstrom range for two of these stars. Thisincludes the hottest known DB star, WD 0112+104, aswell as one hot, pulsating (V777 Her) star. The specificgoal of these observations is twofold: i) To derive anaccurate ultraviolet temperature, T^UV_ eff, which can becompared to that derived from our detailed analysis of theoptical spectrum. Because we believe that existingdiscrepancies between current estimates of these quantitiesare related to the presence of small traces of hydrogen in thephotosphere, which remain invisible in the optical spectrum,we also intend ii) to use the observed Ly-alpha region toestimate, or constrain, the hydrogen abundance in theseobjects. Limits are not available from the ground for DB starsabove (T_ eff >~ 20,000 K), as the Balmer lines fade rapidlyfor increasingly lower hydrogen abundances. By contrast, thewings of Ly-alpha remain useful for detecting hydrogen evenat low abundance values.
No associations
LandOfFree
Ultraviolet Spectroscopy of Hot DB White Dwarfs 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 Ultraviolet Spectroscopy of Hot DB White Dwarfs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ultraviolet Spectroscopy of Hot DB White Dwarfs will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1118144