4U 1630-47

G. Share, K. Wood, E. Byram, J. Meekins, S. Shulman and their collaborators, Naval Research Laboratory; and R. Griffiths, Center for Astrophysics, report the detection by HEAO 1 of the recurrent transient 4U 1630-47 during Mar. 2-7. The measured position was within 0o.2 of the transient, and the 1-10-keV intensity was ~ 5 x 10**-10 erg cm**-2 s**-1. The transient's intensity was ~ 5 x 10**-11 erg cm**-2 s**-1 as measured by A1 in early Sept. 1977 but had flared to 10**-8 erg cm**-2 s**-1 in Nov. 1977 (cf. IAUC 3144). L. J. Kaluzienski, E. A. Boldt, S. S. Holt, R. F. Mushotzky, P. J. Serlemitsos and R. E. Rothschild, Goddard Space Flight Center, independently report the detection by HEAO A2 of a bright x-ray source centered on the position of 4U 1630-47. The flux measured on Mar. 3d13h was ~ 2 x 10**-9 erg cm**-2 s**-1 (2-10 keV), which is more than an order of magnitude greater than the upper limit obtained for 4U 1630-47 during the previous A2 scan of this region conducted during 1977 Sept. 3-9. Since the apparent outburst in Nov. 1977 the average e-folding decay time, measured by the Ariel 5 all-sky monitor, has been ~ 45 days, and this is consistent with the present A2 intensity. Preliminary wide-band spectral colors are indicative of a steep spectrum peaked at E ~ 3 keV.