Image Details
Caption: Fig. 2.
Power spectra in 1992–1994, with significant peaks marked with their periods in seconds. A 1011 s signal, markedly absent in 1997, dominates the low‐frequency regime in 1993 and 1994. The 1992 data is highly aliased, but one of the acceptable aliases occurs at 1028.7 s, the period seen strongly in 1997.
© 1998. The American Astronomical Society. All rights reserved. Printed in U.S.A.