MODEL ATMOSPHERE AND KINEMATICAL ANALYSES OF EARLY-TYPE, HIGH GALACTIC LATITUDE STELLAR CANDIDATES FROM THE UKST UBVRI-SURVEY

被引:14
作者
HAMBLY, NC [1 ]
CONLON, ES [1 ]
DUFTON, PL [1 ]
KEENAN, FP [1 ]
LITTLE, JE [1 ]
MILLER, L [1 ]
机构
[1] ROYAL OBSERV,EDINBURGH EH9 3HJ,MIDLOTHIAN,SCOTLAND
关键词
STARS; ABUNDANCES; ATMOSPHERES; EARLY-TYPE; EVOLUTION;
D O I
10.1086/173349
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
From the UKST UBVRI survey, six high Galactic latitude stars have been previously identified which may be young hydrogen-burning objects. Using high-dispersion optical spectra, model atmosphere analyses are presented for these targets. Two, have normal or nearly normal Population I chemical compositions, one appears to be subluminous while the remaining three are possibly normal late B-type stars. A kinematic analysis indicates that one star having normal parameters is an excellent candidate for formation in the halo, having an evolutionary age an order of magnitude less than the time required for it to attain its current position following ejection from the Galactic disk. A preliminary analysis implies that there may currently be a few thousand normal B-type stars in the Galactic halo with z-distances from the plane of the Galaxy in the ran 3 < z < 22 k
引用
收藏
页码:706 / 712
页数:7
相关论文
共 24 条
[1]   STAR COUNTS AND GALACTIC STRUCTURE [J].
BAHCALL, JN .
ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS, 1986, 24 :577-611
[2]  
BEARD SM, 1990, MON NOT R ASTRON SOC, V247, P311
[3]  
CLARET A, 1992, ASTRON ASTROPHYS SUP, V96, P255
[4]  
CONLON ES, 1990, ASTRON ASTROPHYS, V236, P357
[5]  
CONLON ES, 1989, ASTRON ASTROPHYS, V224, P65
[6]   THE ORIGIN OF DISTANT B-TYPE STARS IN THE GALACTIC HALO [J].
CONLON, ES ;
DUFTON, PL ;
KEENAN, FP ;
MCCAUSLAND, RJH ;
HOLMGREN, D .
ASTROPHYSICAL JOURNAL, 1992, 400 (01) :273-279
[7]  
CONLON ES, 1988, ASTRON ASTROPHYS, V200, P168
[8]  
FULLER NMJ, 1989, STARLINK USER NOTE, V86
[9]   CARBON, NITROGEN, AND OXYGEN ABUNDANCES IN EARLY B-TYPE STARS [J].
GIES, DR ;
LAMBERT, DL .
ASTROPHYSICAL JOURNAL, 1992, 387 (02) :673-700
[10]  
GROTH HG, 1985, ASTRON ASTROPHYS, V152, P107