KIC 1048346: a new roAp star and a challenge for the oblique pulsator model

M. Gruberbauer, L. A. Balona, T. R. White, M. S. Cunha, A. Hatzes, D. W. Kurtz, H. Saio

Abstract.
27 days of high quality space photometry obtained by Kepler during its Q2 short cadence run has revealed a previously unknown rapidly oscillating Ap star. KIC 10483436 shows two distinct groups of pulsation frequencies with amplitudes down to 10 ppm, as well as rotational modulation due to spots. The latter has a period of 4.301 d and the corresponding signal in the periodogram can be reliably detected up to its 26th harmonic, which suggests a very intricately spotted surface. A quintuplet of frequencies is centred at 1352.99 µHz and can be explained by the oblique pulsator model (OPM) as a distorted dipole pulsation mode. Three additional frequencies are also found and possibly members of a second quintuplet centred on 1511.59 µHz. However, two components of this proposed quintuplet, among those the central frequency, are obviously missing. This suggests an unusual deviation from the typical "distorted dipole" characteristic of roAp modes.

Third Kepler Asteroseismology Workshop: 'Kepler Asteroseismology in Action'
Aarhus, Denmark
June 2010

Type: Oral comunication