Detection of δ Scuti-like pulsation in H254, a pre-main sequence F-type star in IC 348^*

¹ Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy
² Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, 50125 Firenze, Italy
³ Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
⁴ Departamento de Astrofísica, Universidad de La Laguna, Avda. Astrofísico F. Sánchez sn, 30071 La Laguna, Spain
⁵ Instituto de Astronomía, UNAM, Apdo. Postal 70-264, México D.F., CP 04510, México

Corresponding author: V. Ripepi, ripepi@na.astro.it

Received: 24 April 2002
Accepted: 29 May 2002

Abstract

We present time series observations of intermediate mass PMS stars belonging to the young star cluster IC 348. The new data reveal that a young member of the cluster, H254, undergoes periodic light variations with δ Scuti-like characteristics. This occurrence provides an unambiguous evidence confirming the prediction that intermediate-mass pre-main sequence (PMS) stars should experience this transient instability during their approach to the main-sequence. 
 On the basis of the measured frequency  d^-1, we are able to constrain the intrinsic stellar parameters of H254 by means of linear, non adiabatic, radial pulsation models. The range of the resulting luminosity and effective temperature permitted by the models is narrower than the observational values. In particular, the pulsation analysis allows to derive an independent estimate of the distance to IC 348 of about 320 pc. Further observations could either confirm the monoperiodic nature of H254 or reveal the presence of other frequencies.