Period Analysis of All-Sky Automated Survey for Supernovae (ASAS-SN) Data on a Sample of “Irregular” Pulsating Red Giants

Volume 48 number 1 (2020)

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John R. Percy

Department of Astronomy and Astrophysics, and Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada; john.percy@utoronto.ca

Abstract

All-Sky Automated Survey for Supernovae (ASAS-SN) data and, for some stars, AAVSO visual and V data have been used to study the possible periodicity of 74 “irregular” pulsating red giants (PRGs) in the AAVSO observing program. Results have been obtained and tabulated for 41 of them. For most of the tabulated stars, the new data provide more and/or better results than AAVSO data alone. All have small amplitudes. Several of the stars appear to have a long secondary period, as well as a pulsation period. A very few may be bimodal. Only about half of the periods that we derive are consistent with the periods in the VSX catalogue. We recommend that the AAVSO consider which of these small-amplitude “irregular” stars should continue to be observed, and how.