2004IAUC.8382....2L

D. K. Lynch, R. W. Russell, and D. Kim, Aerospace Corporation; M. Sitko, University of Cincinnati, and R. B. Perry, Langley Research Center, NASA, report 3- to 13-microns spectroscopy of V1187 Sco using the Infrared Telescope Facility (+ BASS; 3".4- diameter beam) on Aug. 5.35 and 6.25 UT. At the spectral resolving power (30-100), the spectrum showed a fairly smooth continuum between 3 and 10 microns that is well-fitted by a 1500-K blackbody on Aug. 5 and by a 1400-K blackbody on Aug. 6. Atop the continuum, between 3.5 and 5 microns, were a number of poorly resolved emission lines that are believed to include Br_alpha and Humphreys lines. Beyond 8 microns, the spectrum showed structured excess emission. Hu_alpha at 12.3 microns was evident, and it doubled in strength overnight. Also present, but as yet unidentified, were features at 8.6, 10.6 ([S IV] ?) and 11.2 microns, each of which also increased in strength between the Aug. 5 and 6. Infrared magnitudes: Aug. 5, L = 2.9, M = 2.4, N [10.5 microns] = 1.7; Aug. 6, 3.2, 2.7, 1.7. The spectrum is consistent with early development of novae near maximum light where the F-type pseudo- photospheric continuum gives way to an emission-line spectrum that is dominated by H I recombination lines and other low-excitation species. The infrared excess longward of 10 microns may represent thermal emission from pre-existing dust, because dust formation near maximum light is never observed.