A representative sample of Be Stars I: sample selection, spectral classification and rotational velocities
نویسندگان
چکیده
We present a sample of 58 Be stars containing objects of spectral types O9 to B8.5 and luminosity classes III to V. We have obtained 3670− 5070 Å spectra of the sample which are used to derive spectral types and rotational velocities. We discuss the distribution of spectral types and rotational velocities obtained and conclude that there are no significant selection effects in our sample.
منابع مشابه
A representative sample of Be starsII. K band spectroscopy
We present K band (2.05 μm − 2.22 μm) spectra of 66 isolated Be stars of spectral types O9-B9 and luminosity classes III, IV & V. We find that objects with He i features either in emission or absorption are B3 or earlier. Objects with Mg ii emission but no He i are B2 to B4, while objects with Brγ emission but no evidence of He i or Mg ii are B5 or later. Na i emission in the spectra of 4 objec...
متن کاملRotational velocities of A - type stars ⋆ III . Velocity distributions
Aims. In this work, a sample of v sin i of B9 to F2-type main sequence single stars has been built from highly homogeneous v sin i parameters determined for a large sample cleansed from objects presenting the Am and Ap phenomenon as well as from all known binaries. The aim is to study the distributions of rotational velocities in the mass range of A-type stars for normal single objects. Methods...
متن کاملHigh - resolution spectroscopy of ROSAT low - mass pre - main sequence stars in Orion ?
High-resolution spectroscopic observations of the lithium-rich stars found on the basis of the ROSAT All-Sky Survey (RASS) in the general direction of the Orion star forming region are presented. Different properties are derived from the spectra and analyzed: i) the equivalent widths of the lithium 6708 Å absorption line have been measured and a revision of spectral types has been performed; ii...
متن کاملA study of the Chamaeleon star-forming region from the ROSAT all-sky survey
We present the results of a high-resolution spectroscopic study on some 70 stars, discovered recently on the basis of the ROSAT all-sky survey spread over a wide area in the Chamaeleon star forming region and classified as new weakline T Tauri stars. We refine the previous spectral type classification, based on low-resolution spectra, and characterize each star in the sample according to the Hα...
متن کاملar X iv : 0 90 8 . 40 92 v 1 [ as tr o - ph . S R ] 2 7 A ug 2 00 9 Rotation Velocities for M - dwarfs 1
We present spectroscopic rotation velocities (v sin i) for 56 M dwarf stars using high resolution HET HRS red spectroscopy. In addition we have also determined photometric effective temperatures, masses and metallicities ([Fe/H]) for some stars observed here and in the literature where we could acquire accurate parallax measurements and relevant photometry. We have increased the number of known...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1998