Pulsational frequencies in theδScuti stars V624 Tauri and HD 23194

Abstract

Abstract. The results of the tenth multi-site campaign of the STEPHI network are reported. The δ Scuti stars V624 Tau (HD 23156) and HD 23194, belonging to the Pleiades cluster, were observed photometrically for 34 days on three continents during 1999 November-December. An overall run of 343 hours of data was collected. Seven frequencies for V624 Tau and two frequencies for HD 23194 have been found above a 99% confidence level. These results greatly improve those found in previous studies with much less data. A preliminary comparison of observed and theoretical frequencies suggests that both stars may oscillate with radial and non-radial p modes of radial orders typical among δ Scuti stars.

A δ Scuti Variable in the α Persei Cluster: V459 Per

“…The common origin of these stars in the same cluster allows comparison between their individual results. The cases of the Praesepe cluster, with 14 Scuti members, and the Pleiades cluster, with six Scuti members, are very illustrative of this observational effort (Breger 1973;Á lvarez et al 1998;Hernández et al 1998;Michel et al 1999;Fox-Machado et al 2002;Li et al 2004).…”

Strömgren photometry and spectroscopy of the δ Scuti stars 7 Aql and 8 Aql

“…The subsequent panels of each plot in the figure, from top to bottom, illustrate the process of detection of the frequency peaks in each amplitude spectrum. We followed the same procedure as explained inÁlvarez et al (1998) and employed by Fox Machado et al (2000Machado et al ( , 2002aMachado et al ( ,b, 2008b. We have used a threshold of 3.7-σ above the mean noise level of the 100 µHz closest to the peak in the amplitude spectrum to consider a frequency as statistically significant, as described iń Alvarez et al (1998).…”

Pulsational frequencies of the eclipsing δ Scuti star HD 172189. Results of the STEPHI XIII campaign

“…As in previous STEPHI articles (e.g. Álvarez et al 1998;Fox-Machado et al 2002), the confidence levels are calculated with Fisher's test as prescribed by Nowroozi (1967). We search for oscillation peaks in the range 100−600 µHz, which in Nowroozi's description corresponds to around m = 1000 "independent" frequency bins.…”