Is RX Cep a Variable Star? (Abstract)

Volume 28 number 1 (2000)

Richard W., Jr. Schmude

Abstract

(Abstract only) Since 1994, I have estimated the magnitude of RX Cep—identified in the 4th Edition of the General Catalogue of Variable Stars (P. N. Kholopov et al. 1985, Moscow) as SRd:, range = 7.2–8.2V; p = 55: days—282 times using a pair of binoculars. One objective of this study has been to determine if RX Cep is a variable star and if so determine its period of variability. The coordinates and other information for RX Cep and the two comparison stars used in this study are listed in the table below. Star R.A. (2000) Dec. (2000) Spectral Type Magnitude B-V RX Cep 00h 50m 04.s5 +81° 58' 02" G5 ~7.5 ? HD7340 01 18 11.2 +81 33 38 G5 7.7 1.4 HD9653 01 40 31.8 +81 25 47 A0 7.1 0.3 Between JD 2449950 (August 1995) and JD 2450167 (March 1996), 94 magnitude estimates of RX Cep were made and these data were plotted in a magnitude versus time plot. There is no evidence for a 55-day period, however if the magnitude change is smaller than 0.1 magnitude, it will not show up on the graph. There is some evidence for a longer-period magnitude fluctuation. The average magnitude for 20-day intervals was computed and plotted on a magnitude versus date plot. There is evidence for a ~0.2 change in magnitude every 338±12 days, however, atmospheric extinction may have played some role in the results. It is concluded that if RX Cep is a variable that the amplitude is less than 0.3 magnitude.