Observations of Nova Cygni 1992 with a long-baseline optical interferometer

Abstract

Nova Cygni 1992 was observed with the MkIII optical interferometer on several nights in 1992 February; usable data were obtained on February 28 and 29. This marks the first time that a nova has been resolved about 10 days after maximum light. A uniform disk model fitted to the data in three wide-band (25 nm) filters gives a diameter of 3.8 mas. The uniform disk diameter in a 10-nm bandpass centered on the H-alpha line was 5.1 mas. From this number, and adopting an expansion velocity of about 1100 km/s, the distance to the nova is estimated to be about 2.5 kpc.