1999ApJ...516..887B

Query : 1999ApJ...516..887B

1999ApJ...516..887B - Astrophys. J., 516, 887-891 (1999/May-2)

Spectroscopic studies of DB white dwarfs: the instability strip of the pulsating DB (V777 Herculis) stars.

BEAUCHAMP A., WESEMAEL F., BERGERON P., FONTAINE G., SAFFER R.A., LIEBERT J. and BRASSARD P.

Abstract (from CDS):

We have secured optical spectra for the eight currently known variable DB, or V777 Her, stars. With the help of a new generation of synthetic spectra, spectroscopic effective temperatures are derived for these objects, as well as for 15 other DB or DBA stars above 20,000 K. We find that the location of the boundaries of the instability strip is sensitive to the atmospheric hydrogen abundance assumed for DB stars: the strip covers the range 22,400-27,800 K if atmospheres of pure helium are used and the range 21,800-24,700 K if undetectable traces of hydrogen are allowed for in the DB models. These determinations provide independent constraints for current seismological analyses of the V777 Her stars. More sensitive searches for weak hydrogen features in hot DB stars should help decide between the two temperature scales.

Abstract Copyright: ∼

Journal keyword(s): Stars: Atmospheres - Stars: Oscillations - Stars: White Dwarfs

Simbad objects: 23

goto Full paper

goto View the references in ADS

Number of rows : 23
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 EGGR 513 WD* 01 03 24.5382532656 -06 32 10.895411436   13.92 13.91     DB3 52 0
2 EGGR 409 WD* 01 14 37.6538960064 +10 41 04.757053956   15.27 15.41 15.69   DB2.5 75 0
3 KUV 05134+2605 WD* 05 16 27.7878681552 +26 08 37.543234056   16.5 16.70 16.6   DB 40 0
4 EGGR 904 WD* 08 56 18.9476777928 +16 11 03.744751560   15.544 15.595 15.885   DB2 65 1
5 PG 0921+092 ** 09 23 55.2663040536 +08 57 17.461669824   16.3   16.6   DBA+M: 31 0
6 V* SW LMi WD* 09 57 49.4086247376 +33 59 23.691674976   17       DB 61 0
7 V* DT Leo WD* 11 18 22.6936756944 +15 33 34.535147256   16.90   16.88   DB2 54 0
8 PG 1149-133 WD* 11 51 50.5965873432 -13 37 15.781935108   16.09       DB2 27 0
9 PG 1311+129 WD* 13 13 51.2698819320 +12 40 09.563476332   16.21 16.26     DBA 33 0
10 PG 1326-037 WD* 13 29 16.3937781024 -03 58 51.729824064     15.7     DB2 26 0
11 V* EM UMa WD* 13 53 09.9687043752 +48 40 21.171407268   16.5   17.0   DB2 105 0
12 PG 1445+153 WD* 14 48 14.3731494768 +15 04 49.731182436   15.55 15.6     DB 35 0
13 V* CW Boo WD* 14 58 32.6381816376 +10 08 18.108688128   15.89       DBA 59 0
14 PG 1540+681 WD* 15 40 38.2134281040 +67 56 13.846883460   16.2 16.44 16.1   DB3 18 0
15 GD 190 WD* 15 44 19.4543884752 +18 06 43.775072424 13.537 14.556 14.677 14.767 14.849 DB2 94 0
16 GD 198 WD* 16 15 23.9764472064 -11 18 30.091464468   15.42 15.53     DB 33 0
17 GD 358 WD* 16 47 18.3925183824 +32 28 32.862804384 12.511 13.530 13.653 13.752 13.852 DB2 364 0
18 PG 1654+160 WD* 16 56 57.4672879608 +15 56 27.791267532           DB2 55 0
19 GD 205 WD* 17 11 55.6598934984 +23 01 01.525512072   14.81   15.1   DBAZ 45 0
20 V* QU Tel WD* 20 09 40.1871967824 -52 25 15.864452508 14.51 15.25 15.03     DB2 60 1
21 EGGR 907 WD* 22 36 41.9752381392 +06 40 17.431231692   16.06 16.17 16.14   DB2 22 0
22 EGGR 908 WD* 22 48 45.4800657240 +12 20 07.219101336   16.6   16.6   DB4 27 0
23 PG 2354+159 WD* 23 56 34.7462697000 +16 15 40.257339876   15.78   16.15   DBZ 30 0

To bookmark this query, right click on this link: simbad:objects in 1999ApJ...516..887B and select 'bookmark this link' or equivalent in the popup menu