Faculty Publications

New 1982 - 1990 Photometry Of Λ Andromedae And Its 11-Year Cycle

Document Type

Article

Keywords

binaries, RS CVn stars, stars, individual

Journal/Book/Conference Title

Journal of Astrophysics and Astronomy

Volume

12

Issue

4

First Page

281

Last Page

287

Abstract

We present photoelectric photometry of λ And never before published, obtained between February 1982 and December 1990 at 29 different observatories. Then we combine it with all other photometry available to us (previously published, contained in the I.A.U. Commission 27 Archives, and obtained with the Vanderbilt 16-inch automatic telescope but not yet published), to yield a 14.8-year data base. Analysis reveals a long-term cycle in mean brightness, with a full range of 0m.15 and a period of 11.4 ± 0.4 years. Because most of our new photometry was concentrated in the 1983-84 observing season, we analyze that one well-defined light curve with a two-spot model. Spot A keeps a 0m.04 amplitude throughout four rotation cycles whereas the amplitude of spot B diminishes from 0m.09 down almost to 0m.03. The spot rotation periods were 55d.9 ± 0d.6 and 520d.8 ± 1d.0, respectively. © 1991 Indian Academy of Sciences.

Department

Department of Earth Science

Original Publication Date

12-1-1991

DOI of published version

10.1007/BF02702317

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