J/AJ/132/676 SDSS hot DB white dwarfs (Eisenstein+, 2006)
Hot DB white dwarfs from the Sloan Digital Sky Survey.
Eisenstein D.J., Liebert J., Koester D., Kleinman S.J., Nitta A.,
Smith P.S., Barentine J.C., Brewington H.J., Brinkmann J., Harvanek M.,
Krzesinski J., Neilsen E.H.JR, Long D., Schneider D.P., Snedden S.A.
<Astron. J., 132, 676-691 (2006)>
=2006AJ....132..676E 2006AJ....132..676E
ADC_Keywords: Stars, white dwarf ; Proper motions
Keywords: stars: atmospheres - stars: evolution - white dwarfs
Abstract:
We present ugriz photometry and optical spectroscopy for 28 DB and DO
white dwarfs with temperatures between 28000 and 45000K. About 10
of these are particularly well observed; the remainder are candidates.
These are the hottest DB stars yet found, and they populate the DB gap
between the hotter DO stars and the familiar DB stars cooler than
30000K. Nevertheless, after carefully matching the survey volumes we
find that the ratio of DA stars to DB stars is a factor of 2.5 larger
at 30000 than at 20000K, suggesting that the DB gap is indeed
deficient and that some kind of atmospheric transformation takes place
in roughly 10% of DA stars as they cool from 30000 to 20000K.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 99 28 Hot DB White Dwarf Candidates
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See also:
http://www.sdss.org/ : SDSS Home page
II/267 : The SDSS Photometric Catalog, Release 4 (Adelman-McCarthy+, 2006)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [SDSS]
6- 24 A19 --- SDSS SDSS name (JHHMMSS.ss+DDMMSS.s)
26- 30 A5 --- SpType Spectroscopic class
33- 36 I4 --- Plate SDSS Plate number
38- 40 I3 --- Fiber SDSS Fiber number
42- 46 I5 --- MJD SDSS MJD number
48- 51 I4 --- Run SDSS run number
53- 54 I2 --- Rerun SDSS rerun number
56 I1 --- Camcol SDSS camcol number
58- 60 I3 --- Field SDSS field number
62- 64 I3 --- Obj SDSS obj number
66 A1 --- HS? [Y/N] Whether or not (Y or N) the object was
targeted as a hot standard (1)
68- 77 F10.6 deg RAdeg Right ascension in decimal degrees (J2000)
79- 88 F10.6 deg DEdeg Declination in decimal degrees (J2000)
90- 93 F4.2 10mas/yr pm Proper motion from the USNOB catalog
(in arcsec/century)
95- 99 F5.1 deg pmPA Direction of proper motion (north through east)
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Note (1): If so, the object received high priority in fiber allocation; if
not, the object was targeted through the star or serendipity sets and
received lower priority.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 11-Jan-2008