DISTANCE and REDDENING of the ENIGMATIC GAMMA-RAY-DETECTED NOVA V1324 SCO

It has recently been discovered that some, if not all, classical novae emit GeV gamma-rays during outburst. Despite using an unreliable method to determine its distance, previous work showed that nova V1324 Sco was the most gamma-ray luminous of all gamma-ray-detected novae. We present here a different, more robust, method to determine the reddening and distance to V1324 Sco using high-resolution optical spectroscopy. Using two independent methods, we derived a reddening of E (B - V) = 1.16 ±0.12 and a distance limit of r_D > 6.5 kpc. This distance is>40% greater than the value used in the gamma-ray analysis, meaning that V1324 Sco has an even higher gamma-ray luminosity than previously calculated. We also use periodic modulations in the brightness, interpreted as the orbital period, in conjunction with pre-outburst photometric limits to show that a main-sequence companion is strongly favored.