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Abrupt Pulsation Resumptions in Deneb: An Update by Guzik, Joyce A.; Kloppenborg, Brian; Richardson, Noel; Jackiewicz, Jason; Morrison, Nancy; Calderwood, Tom; Pigulski, Andrzej is a scholarly article available to read on EtoBox.

What is Abrupt Pulsation Resumptions in Deneb: An Update about?

Deneb, the prototype Alpha Cygni variable, is a bright A2 Ia supergiant which shows irregular variability with a 12-day quasi-period, presumed to be caused by pulsations. At the 2023 AAVSO Annual Meeting we discussed radial velocity and photometry data from several sources showing that the 12-day variations begin abruptly at an arbitrary phase, damp out after several cycles, and resume at intervals of around 75 days. Additional data with more frequent time sampling and longer time series were needed to verify the existence and precision of the 75-day interval. We have identified additional data sets and have intensified ground-based observing programs. Here we present analysis of 1) an 8.6-year photometric data set from the Solar Mass Ejection Imager; 2) BRITE Constellation light curves from six observing seasons of 60 to 180 days each, 2014-2021; 3) 4.6 years of radial velocity data from Morrison; 4) 1.4 years of radial velocity data from Eaton; and 5) additional V-band photometry from the AAVSO Photoelectric Photometry (PEP) section. Examining the SMEI data set, we find a most common 100 to 125 day interval between `pulsation' resumptions. These resumptions sometimes skip interva

Author

Guzik, Joyce A.; Kloppenborg, Brian; Richardson, Noel; Jackiewicz, Jason; Morrison, Nancy; Calderwood, Tom; Pigulski, Andrzej

Published

2025

Language

EN