J/A+A/402/963 Stephenson H{alpha} stars (Maheswar+, 2003) ================================================================================ Optical spectroscopic and 2MASS measurements of Stephenson H{alpha} stars. Maheswar G., Manoj P., Bhatt H.C. =2003A&A...402..963M ================================================================================ ADC_Keywords: Stars, pre-main sequence ; Stars, emission ; Photometry, CCD ; Photometry, infrared Keywords: stars: emission-line, Be - stars: general - stars: pre-main sequence - stars: late-type - infrared: stars Abstract: We present the results of spectroscopic observations for 52 objects from the list of H{alpha} emission stars of Stephenson (1986ApJ...300..779S). Out of six known T Tauri stars observed, five showed H{alpha} in emission and in one (StHa 40), H{alpha} changed from being in absorption to emission over a period of two years, accompanied by photometric and spectral type variability. We confirm the T Tauri nature of one Stephenson object (StHa 48) on the basis of the presence of H{alpha} and H{beta} in emission, Li I {lambda}6708 in absorption, infrared excess and X-ray emission. Among the 52 objects observed, there were other emission line objects: 1 Ke star, 1 BQ[] star, 2 galaxies and 2 Be stars. We present a higher-resolution spectrum of StHa 62 showing permitted and forbidden lines in emission typical of BQ[] stars. Twenty five out of 30 newly observed objects failed to show H{alpha} in emission. We also present 2MASS observations for 112 StHa objects. We suggest three Stephenson objects (StHa 52, 125 and 129) to be YSOs on the basis of 2MASS, IRAS and ROSAT observations. These and all other known YSOs amongst StHa stars are found in regions of star-forming clouds in Taurus, Orion and Ophiuchus. YSOs at high galactic latitudes in other parts of the sky are therefore rare. Description: Optical CCD spectra of StHa stars were obtained using the OMR (Optomechanics Research) spectrograph (Prabhu et al., 1998, Bulletin of the Astronomical Society of India, 26, 383) on the 2:34m VBT at Vainu Bappu Observatory during the period 1999-2002. StHa 57 was observed on 3 January 2003. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table2.dat 109 146 2MASS, IRAS and ROSAT results of Stephenson stars object table2.tex 159 215 LaTeX version of table2 refs.dat 92 18 References -------------------------------------------------------------------------------- See also: J/ApJ/300/779 : High-latitude H-alpha emission stars (Stephenson+, 1986) V/73 : Emission-Line Stars of the Orion Population (Herbig+ 1988) V/110 : Catalog of Cataclysmic Variables (Downes+ 2001) Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 A4 --- --- [StHa] 6- 8 I3 --- StHa StHa number (Stepheson, 1986ApJ...300..779S) 10- 14 F5.3 arcmin r ? Distance StHa star to the 2MASS detection 16- 21 F6.3 mag Jmag ? J magnitude 23- 26 F4.2 mag e_Jmag ? rms uncertainty on Jmag 28- 33 F6.3 mag Hmag ? H magnitude 35- 38 F4.2 mag e_Hmag ? rms uncertainty on Hmag 40- 44 F5.2 mag Ksmag ? Ks magnitude 46- 49 F4.2 mag e_Ksmag ? rms uncertainty on Ksmag 51- 55 F5.2 mag J-H ? J-H colour index 57- 61 F5.2 mag H-Ks ? H-Ks colour index 63- 70 A8 --- SpType Spectral Type 72- 73 I2 --- r_SpType ? References for spectral type, in refs.dat file 76- 80 F5.3 arcmin DistIRAS ? Radial distance of IRAS detection 82- 86 F5.3 arcmin DistROSAT ? Radial distance of ROSAT detection 88-102 A15 --- Class Class of object 103-104 A2 --- n_Class [*+d ] Note on Class (1) 107-108 I2 --- r_Class ? Reference for Class, in refs.dat file -------------------------------------------------------------------------------- Note (1): Notes on Class: *: Stars that are in common with those of Downes & Keyes (1988AJ.....96..777D). +: semi-regular pulsating variable star d: Planetary nebula -------------------------------------------------------------------------------- Byte-by-byte Description of file: refs.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 2 I2 --- Ref Reference number 4- 22 A19 --- BibCode BibCode 24- 51 A28 --- Aut Author's name 56- 92 A37 --- Com Comments -------------------------------------------------------------------------------- Acknowledgements: Maheswar Gopinathan ================================================================================ (End) Patricia Bauer [CDS] 29-Apr-2003