Is 44 Tauri an exceptional case among the δ Scuti stars?

¹ Institut für Astronomie der Universität Wien, Türkenschanzstr. 17, 1180 Wien, Austria e-mail: antoci@univie.ac.at
² Max Planck Institut für Astronomie, 69117 Heidelberg, Königstuhl 17, Germany
³ Instituto de Astrofisica de Andalucia, CSIC, Apdo. 3004, 18080 Granada, Spain

Received: 18 April 2006
Accepted: 13 September 2006

Abstract

Aims.This paper investigates the pulsational behavior of the exceptionally slow rotating δ Scuti star 44 Tau.

Methods.During 2000 and 2003 we carried out a photometric observing campaign and obtained 470 h of Strömgren photometry (v and y).

Results.We observed 29 pulsational frequencies, from which 16 linear combinations were detected. Amplitude variations were found to be significant for three frequencies. Furthermore a close frequency pair was derived. The pulsational constant Q has been calculated for all frequencies. The radial fundamental and the first overtone were identified based on Q and the positive phase shifts in all three observing seasons. Additionally we found evidence for the presence of g modes. The newly derived value of the projected rotational velocity of  = 2 ± 1 km s^-1 is discussed.

Conclusions.Fast rotation can be excluded, but there are no evident proofs to favor slow rotation or pole-on view.