Star formation in the Cepheus Flare region - II. A-type stars associated with IRAS sources

Citation
M. Kun et al., Star formation in the Cepheus Flare region - II. A-type stars associated with IRAS sources, M NOT R AST, 319(3), 2000, pp. 777-790
Citations number
65
Categorie Soggetti
Space Sciences
Journal title
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
ISSN journal
00358711 → ACNP
Volume
319
Issue
3
Year of publication
2000
Pages
777 - 790
Database
ISI
SICI code
0035-8711(200012)319:3<777:SFITCF>2.0.ZU;2-H
Abstract
In order to reveal the star-forming history of the molecular cloud complex we studied the intermediate mass stellar population in the Cepheus Flare re gion. (Paper I dealt with the distance and the young stellar object candida tes of the region.) Correlating the IRAS Point Source Catalogue and Faint S ource Catalogue positions with those of 1214 B8-A8 and 1760 F0-F5 type star s brighter than V approximate to 13 mag and classified during an objective prism survey, we identified 19 stars showing far-infrared excess emission i n the Cepheus Flare region. In addition to the 16 stars whose counterparts are given in the IRAS catalogues, we found three more stars with infrared e xcess not recognized before. In order to identify the young medium-mass sta rs associated with the Cepheus Flare molecular clouds we observed the optic al spectra of the IR-excess stars, and using published optical photometry a nd the IRAS data we examined their spectral energy distributions (SEDs) and IRAS two-colour diagram. The observations resulted in the discovery of a n ew Herbig Ae/Be star, BD +68 degrees 1118, coinciding with IRAS 21169+6842. More evolved HAe/Be stars may be SAO 19953, BD +67 degrees 1314 and BD +69 degrees 1231, whose H alpha lines showed weak emission components. Possibl e beta Pictoris- or Vega-type stars may be HD 203854, HD 212826 and HD 2164 86, whereas the far-infrared fluxes at the positions of ED +72 degrees 1018 , HD 210806 and HD 217903 can be attributed to the heating of the interstel lar environment. We used distances and radial velocities of the stars deriv ed from the spectroscopy and published optical photometry as indicators of their relations to the clouds. Information on the environment of the observ ed stars deduced from the diffuse interstellar band at lambda 6613 is brief ly discussed.