The γ Dor variable HD 164615: Results from a multisite photometric campaign

Publication date: 
Main author: 
Zerbi F.M.
IAA authors: 
Zerbi, F.M.;Rodríguez, E.;Garrido, R.;Martín, S.
Zerbi F.M., Rodríguez E., Garrido R., Martín S., Akan K., Luedeke K., Keskin V., Ibanoǧlu C., Evren S., Tunca Z., Pekünlü R., Paparó M., Nuspl J., Krisciunas K., Jiang S.Y.
Monthly Notices of the Royal Astronomical Society
Publication type: 
We present in this paper the results from a multisite photometric campaign devoted to the γ Dor variable HD 164615. During the campaign data were collected in the Johnson and Strömgren photometric systems. A first search for sinusoidal periodicities yielded a three-term solution with frequencies f1 = 1.2328, f2 = 1.0899 and f3 = 2.3501 d-1, and a long-term trend f4 = 0.1301 d-1. The star may therefore be multiperiodic with each frequency related to a pulsation mode. However, a further examination of the curve provided evidence that the amplitude at the instant of maximum brightness is modulated. Alternatively, HD 164615 may be a monoperiodic variable with frequency f1 = 1.2321 d-1, showing amplitude modulation with frequency f4 = 0.1301 d-1. The presence in the power spectra of the coupling terms f2 = f1 - f4 and f3 = f1 + f4 - 1 supports the latter interpretation. In the monoperiodic case the previously given interpretation based on a spot carried through the visible disc by rotation still holds, provided that the spot is bright and evolves on a time-scale of a few days. However, similarities with other γ Dor stars provide indirect indication in favour of the existence of a non-radial pulsation interpretation. © 1997 RAS.
Stars: individual: HD 164615; Stars: variables: other