Identification of blue high proper motion objects in the Tycho-2 and 2MASS catalogues using Virtual Observatory tools
Centro de Astrobiología (INTA-CSIC), Departamento de
Astrofísica, PO Box
Villanueva de la Cañada,
2 Spanish Virtual Observatory, Spain
3 Saint Louis University, Madrid Campus, Division of Science and Engineering, Avenida del Valle 34, 28003 Madrid, Spain
4 Centro de Astrobiología (INTA-CSIC), Departamento de Astrofísica, Carretera de Ajalvir km 4, 28850 Torrejón de Ardoz, Spain
Received: 16 June 2010
Accepted: 12 September 2010
Aims. With available Virtual Observatory tools, we looked for new bright blue high proper motion objects in the entire sky: white dwarfs, hot subdwarfs, runaway OB stars, and early-type stars in nearby young moving groups.
Methods. We performed an all-sky cross-match between the optical Tycho-2 and near-infrared 2MASS catalogues with Aladin, and selected objects with proper motions μ > 50 mas yr-1 and colours VT − Ks < −0.5 mag with TOPCAT. We also collected multi-wavelength photometry, constructed the spectral energy distributions and estimated effective temperatures from fits to atmospheric models with VOSA for the most interesting targets.
Results. We assembled a sample of 32 bright blue high proper motion objects, including ten sdO/B subdwarfs, nine DA white dwarfs, five young early-type stars (two of which are runaway stars), two blue horizontal branch stars, one star with poor information, and five objects reported for the first time in this work. These last five objects have magnitudes BT ≈ 11.0–11.6 mag, effective temperatures Teff ≈ 24000–30 000 K, and are located in the region of known white dwarfs and hot subdwarfs in a reduced proper motion-colour diagram. We confirmed the hot subdwarf nature of one of the new objects, Albus 5, with public far-ultraviolet spectroscopic data obtained with FUSE.
Key words: astronomical databases: miscellaneous / virtual observatory tools / stars: early-type / stars: peculiar / subdwarfs / white dwarfs
© ESO, 2010