Photometry of eta Aquilae (Abstract)

Volume 34 number 2 (2006)

Jerry Doug West

William Douglas Hodgson

Kenneth D. Luedeke

Abstract

(Abstract only) Eta Aql is a classical Cepheid variable of the delta Cephei type. Visually it varies visual magnitude 3.5 to 4.6. In the J infrared band, the star varies from magnitude 2.2 to 2.7 and in the H infrared band it varies from magnitude 1.9 to 2.2. This paper reports on J (1.25 micron) and H (1.65 micron) photometry gathered by the AAVSO Infrared Photometry Group using the SSP-4 photometer. This collection of observations represents the most extensive consistent set of J and H band observations reported in the literature for this star. Reduction of the observations reveals a period of variation of 7.1760 ± 0.0037 days. The J and H band observations lag the visual observations by approximately 0.2 cycle.