Nova Vulpeculae 1984 No. 2

R. D. Gehrz, G. L. Grasdalen and J. A. Hackwell, University of Wyoming Infrared Observatory, write: "Infrared photometry and spectrophotometry on May 14.4, 15.4 and 16.4 UT show that the expanding shell of this nova is in a free-free development phase. These observations were made ~ 150 days after the discovery date. H(5->4) on May 16.4 has a peak flux of ~ 6 Jy and a velocity width of ~ 5000 km/s. An intense 12.8-micron Ne II emission line (May 15.4) stands a factor of ~ 50 above the continuum at a spectral resolution of Delta-lambda/lambda ~ 0.015, has a velocity width of ~ 5000 km/s and a peak intensity of ~ 60 Jy. Preliminary reduction for May 14.4 gives magnitudes of [2.3 microns] = 7.2, [3.6 microns] = 6.0, [4.9 microns] = 5.6, [8.7 microns] = 4.3, N = 2.6, [11.4 microns] = 3.2, [12.6 microns] =1.6, Q = 2.5. Wyoming photometry by M. Greenhouse on Apr. 28.4 yielded magnitudes J = 7.9, H = 8.0, [2.3 microns] = 7.2, [3.6 microns] = 5.9." H. Ogelman, Max-Planck Institut fur Extraterrestrische Physik; and J. Krautter, Landessternwarte Konigstuhl, telex: "Nova Vul 1984 No. 2 was observed with the EXOSAT satellite during Apr. 18.96-19.22 UT and detected at 3-sigma level with the low-energy (0.04- 2 keV) telescope. This observation constitutes the earliest x-ray detection after outburst of a classical nova (3.7 months), thereby indicating the timescale for the ejected shell to become transparent to x-rays. We have also observed this object with the IUE satellite on Apr. 29.1. The spectrum is dominated by emission lines superposed on a strong continuum, and P-Cyg absorption components exist with terminal velocities ~ 5000 km/s."