1997-2019 automated B,V phot. of gam Cas

DOI

{gamma} Cassiopeiae (B0.5IVe) is the noted prototype of a subgroup of classical Be stars exhibiting hard thermal X-ray emission. This paper reports results from a 23yr optical campaign on this star with an automated photometric telescope (APT). A series of unstable long cycles of length 56-91days has nearly ceased over the last decade. Also, we revise the frequency of the dominant coherent signal at 0.82238/days. This signal's amplitude has nearly disappeared in the last 15yr but has somewhat recovered its former strength. We confirm the presence of secondary nonradial pulsation signals found by other authors at frequencies 1.24, 2.48, and 5.03days^-1^. The APT data from intensively monitored nights reveal rapidly variable amplitudes among these frequencies. We show that peculiarities in the 0.82days^-1^ waveform exist that can vary even over several days. Although the 0.82days^-1^ frequency is near the star's presumed rotational frequency, because of its phase slippage with respect to a dip pattern in its far-UV light curve, it is preferable to consider the UV pattern, not the 0.82days^-1^ signal, as associated with rotational modulation. We also find hints of the UV dip pattern in periodograms of seasonal data early in our program.

Identifier
DOI http://doi.org/10.26093/cds/vizier.19150013
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJ/915/13
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/915/13
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/915/13
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJ/915/13
Provenance
Creator Smith M.A.; Henry G.W.
Publisher CDS
Publication Year 2023
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy