VARIATIONS IN THE LIGHT CURVE OF SV CAMELOPARDALIS

Abstract

The eclipsing binary SV Camelopardalis was reobserved during the spring of 1962, and the light curve is compared here to that observed by Huffer and Nelson1 in 1951. The 1962 observations were made with the new 24-inch reflector at San Diego State College. This instrument is equipped with a photometer using a refrigerated 1P21 photomultiplier and standard Johnson-Morgan U, B, V filters.2 The photometer, built in the observatory shop by R. J. Roome and G. O. Jones, is of conventional design, and the associated electronic equipment is composed of standard commercially available units. The linearity of the amplifier was tested by using a potentiometer, and the linearity and color response of the entire system was tested by observing a number of stars in M 39. The results compare satisfactorily with those published by Johnson for this cluster.3 Figure 1 shows the light curve of SV Camelopardalis in 1951 with HD 44706 as a comparison star; Figure 2 shows it in 1962 when HD 43883 was used as a comparison star. This binary has an interesting history of variations in its light curve, beginning with the 1946 report by Wood.4 His 1939 photographic observations show a hump of about 0TM2 in the light curve just preceding primary minimum. Huffer and Nelson found the situation reversed;1 that is, in 1951 the maximum following primary minimum was about 0^05 higher than the other maximum. The 1962 curve once again shows the high maximum preceding the primary minimum, but the difference between maxima is in this case about 0TMl. The 1948-49 light curve published by DeWitt and Seyfert5 does not show this effect to any noticeable extent, but the 194950 observations of G. E. Kron and Mrs. Kron6 led them to classify SV Camelopardalis, along with AR Lacertae and RT Andromedae as a binary whose light-curve peculiarities may be interpreted in terms of surface spots. Hiltner's 1947 light curve7