[vsnet-chat 4487] V1981 Cyg visual data

["Ondrej Pejcha" <opejcha@volny.cz>]

Dear All,

V1981 Cyg (= HR 8062) is one of the very few giants with
enhanced abundandce of Tc, that do not vary very much. Other
Tc stars are usually large amplitude pulsators. Fernie
(1991) analysed his and Snyder's (1990) data resulting into
the period of 34.33 days and amplitude of max. 0.2 mag in
Stromgren y band.

I did DFT on 218 visual estimates of V1981 Cyg contained in
MEDUZA database covering almost two years. The quite
prominent period is the 34.78 days one, with semi-amplitude
of 0.04 mag.

It is interesting how accurate visual observations are, even
at very low amplitude. And please note, that all estimates
were done between the only two suitable comparisons about
0.6 mag apart.

Best regards,

Ondrej Pejcha

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