2008IAUC.8948....1R

R. W. Russell, R. J. Rudy, and D. K. Lynch, The Aerospace Corporation; C. E. Woodward, University of Minnesota; and H. Marion, University of Texas and Texas State University, report observations of V5579 Sgr (cf. IAUC 8937, 8940) on May 9 UT at the Infrared Telescope Facility (+ SPEX; range 0.8-5.2 microns). D. Griep, IRTF, helped to acquire the data. The nova was at a very early stage of its spectral development, showing lines of O I, N I, and Ca II, and exceptionally strong lines of C I. Lines widths were approximately 1600 km/s at FWHM. Fe II features were weak, but – despite that fact – this is almost certainly an "Fe II"-type of nova. Lines of neutral helium had not yet formed. The strongest lines in the infrared spectrum are the O I lines that are fluourescently excited by Lyman_beta. These lines indicate a reddening of E(B-V) = 1.2, some of which may be local to the nova, which has already formed dust. In fact, the infrared continuum is dominated by thermal emission from dust at a single temperature of 1370 K.