Multiperiodic pulsations in the Be stars NW Ser and V1446 Aql

Author(s): Gutierrez-Soto, J.; Fabregat, J.; Suso, J.; et al.

Book Editor(s): Stefl, S; Owocki, SP; Okazaki, AT

Conference: Conference on Active OB-Stars – Laboratories for Stellar and Circumstellar Physics Location: Sapporo, JAPAN Date: AUG 29-SEP 02, 2005

Sponsor(s): Hokkaido Univ, 21st Cent COE Program Topol Sci & Technol; Japan Soc Promot Sci

Source: Active OB-Stars: Laboratories for Stellar and Circumstellar Physics, Proceedings  Book Series: ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES   Volume: 361   Pages: 84-90   Published: 2007

We present accurate differential photometry of two Be stars: NW Ser and V1446 Aql. Both stars show rapid variations in amplitude, probably due to a beating phenomenon. The spectral analysis confirms the presence of two close frequencies. A preliminary instability analysis indicates that l = 2 or e = 3 g modes are predicted unstable for both stars. In addition, NW Ser could be one of the very few beta Cephei and SPB hybrid star. This would be the first unambiguous ground-based detection of photometric multiperiodicity in Be stars which may constitute a proof of the presence of non-radial pulsations (nrp) as the origin of the short-term variability. Further spectroscopic and photometric observations are planned in order to confirm the detected frequencies.