The early infrared temporal development of Nova Delphini 2013 (v339 del) observed with the stratospheric observatory for infrared astronomy (Sofia) and from the ground

We present ground-based infrared photometry, JHK spectroscopy, and 5-28 micron SOFIA FORCAST spectroscopy documenting the early temporal development of Nova Delphini 2013 (V339 Del). We derive a distance of ˜4.5 kpc using data available from the early expansion of the fireball. This distance gives an outburst luminosity of ˜8.3 × 10^5 solar luminosities making V339 Del the most luminous CO nova on record. Our data provide new constraints on the ejected gas mass and the dust yield in fast CO novae. The ejected gas mass as estimated by the cutoff wavelength during the free-free emission phase is ˜7.5 × 10^-5 solar masses. There is evidence for the formation of ˜1.2(±0.4) × 10^-7 solar masses of dust about 102 days after outburst. The gas to dust ratio of ˜470/1-940/1 implies that dust production was much less efficient in V339 Del than is the case for most CO novae.