Ostensen, Roy × Solheim, JE Heber, U Silvotti, R Dreizler, S Edelmann, H #
E d p sciences
Astronomy and astrophysics vol:368 issue:1 pages:175-182
We report the detection of short period oscillations in the sdB stars B80815+4243, HS2149+0847 and HS 2201+2610 from time-series photometry made at the Nordic Optical Telescope (NOT) from a sample of 31 candidates. Hence these three hot subdwarfs are new members of the EC 14026 class of pulsating sdB stars. One short period is detected for HS 0815+4243 (P similar to 126 s; A similar to 7 mma) and two short periods are seen for HS 2149+0847 (P similar to 142, 159 s; A similar to 11, 7 mma), whereas the single oscillation detected for HS 2201+2610 has a considerably longer period (P similar to 350 s; A similar to 11 mma). Our NLTE model atmosphere analysis of the time-averaged optical spectra indicate that HS 0815+4243 has T-eff = 33 700 K and log g = 5.95, HS 2149+0847 has T-eff = 35 600 K and log g = 5.9, and HS 2201+2610 has T-eff = 29 300 K and log g = 5.4. This places the former two at the hot end and the latter at the cool end of the theoretical sdBV instability strip.