Access to Astronomical Catalogues

← Click to display the menu
J/A+A/334/987       6 blue objects spectral data (Venn+ 1998)

New identifications for blue objects towards the Galactic center: post-AGB stars, Be/disk stars, and others Venn K.A., Smartt S.J., Lennon D.J., Dufton P.L. <Astron. Astrophys. 334, 987 (1998)> =1998A&A...334..987V (SIMBAD/NED BibCode)
ADC_Keywords: Blue objects ; Stars, early-type ; Spectroscopy Keywords: stars: abundances - stars: emission-line, Be - fundamental parameters - supergiants - stars: AGB, post-AGB - stars: supergiants - Galaxy: centre Abstract: As part of a programme to investigate spatial variations in the Galactic chemical composition, we have been searching for normal B-type stars and A-type supergiants near the Galactic center. During this search we have found eleven peculiar stars, and in some cases performed detailed abundance analyses of them which suggest that they may be at a post-AGB evolutionary stage. The A-type post-AGB candidates show [Fe/H]=-1.0 to -2.0, and [O/Fe]~+1.4, typical of the post-AGB abundance patterns discussed in the literature. One star, LS 3591 (=SAO 243756), has also been examined recently by Oudmaijer (1996A&A...306..823O); its spectrum appears to be changing very rapidly, which may indicate erratic mass loss or the incipient formation of a planetary nebula. A B-type post-AGB candidate, LS 4950, has a similar spectrum to a well studied post-AGB star, LSIV -12 111. However, an examination of the line strengths and elemental abundances of LS 4950 show that it is peculiar for both a PopulationII, post-AGB, B-type star and for a normal, PopulationI, B-type supergiant. Two other B-type stars, LS 4825 and LS 5112, are either post-AGB stars near the Galactic center or normal B-type supergiants lying well beyond the Galactic center. In addition, several Be-type stars have been newly (or more clearly) identified from our spectra. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 16 25 02.5 -60 03 32 LS 3591 16 24 39.3 -54 38 08 LS 3593 18 21 47.0 -29 45 07 LS 4950 17 17 07.4 -24 45 40 LS 4039 18 16 00.4 -30 45 46 LS 4825 18 40 48.4 -17 04 36 LS 5112 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file appena.dat 42 86 *Spectral line data for two post-AGB A-type stars appenb.dat 38 56 *Spectral line data for four B-type stars towards the Galactic Center appen.tex 65 276 LaTeX version of the tables appen.ps 72 440 PostScript version of the tables
Note on appena.dat: appena.dat correspond to tables 12 and 13 Note on appenb.dat: appenb.dat correspond to tables 14 and 15
See also: VI/72 : Atomic Transition Probabilities, Sc-Ni (NIST 1993) Byte-by-byte Description of file: appena.dat
Bytes Format Units Label Explanations
1- 5 A5 --- Ion Ion 7- 13 F7.2 0.1nm lambda Wavelength 15- 17 I3 --- RMT Multiplet number 19- 23 F5.2 eV chi Excitation potential 25- 29 F5.2 --- loggf log of oscillator strength 31- 33 I3 0.1nm EWLS3591 ? Equivalent width for the star LS 3591 34 A1 --- u_EWLS3591 Uncertainty flag on EWLS3591 36- 38 I3 0.1nm EWLS3593 ? Equivalent width for the star LS 3593 40- 42 A3 --- r_loggf Reference for the oscillator strength (1)
Note (1): References for the atomic data. fmw = Fuhr, Martin & Wiese 1988, Cat. VI/72, J. Phys. Chem. Ref. Data 17, Suppl.4. nk = Kurucz 1990, Trans IAV B, 20, 168 (magnetic tape) ob = O'Brien et al. 1991, J. Opt. Soc. Am. B, 8, 1185 op = Opacity Project (O I, Hibbert et al. 1991, J. Phys B, 24, 3943) zhu = Zhu et al. 1989, Phys Rev A., 40, 3721 wm = Wiese & Martin 1980, NSRDS-NBS 68 wsm = Wiese, Smith, & Martin 1969, NSRDS-NBS 22 sl = Sigut & Landstreet, 1990MNRAS.247..611S
Byte-by-byte Description of file: appenb.dat
Bytes Format Units Label Explanations
1- 6 A6 --- Ion Ion (1) 8- 14 F7.2 0.1nm lambda Wavelength 15 A1 --- --- [,] Separation comma 16- 22 F7.2 0.1nm lambda2 ? Second wavelength (2) 24- 26 I3 0.1nm EWLS4950 ? Equivalent width for the star LS 4950 28- 30 I3 0.1nm EWLS4039 ? Equivalent width for the star LS 4039 32- 34 I3 0.1nm EWLS4825 ? Equivalent width for the star LS 4825 36- 38 I3 0.1nm EWLS5112 ? Equivalent width for the star LS 5112
Note (1): All atomic data has been taken from the compilation by S. Jeffrey 1991 Newsletter on the Analysis of Astronomical Spectra, No. 16, p. 17. Note (2): Where two lines are listed together, they represent an unresolved blend (only blends of the same species are included).
Acknowledgements: Kim A Venn
(End) Patricia Bauer [CDS] 23-Mar-1998
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service

© UDS/CNRS

Contact