Interferometric Observations of V838 Monocerotis
  We have used long-baseline near-IR interferometry to resolve the peculiar eruptive variable V838 Mon and to provide the first direct measurement of its angular size. Assuming a uniform disk model for the emission we derive an apparent angular diameter at the time of observations (November-December 2004) of $1.83 \pm 0.06$ milli-arcseconds. For a nominal distance of $8\pm2$ kpc, this implies a linear radius of $1570 \pm 400 R_{\odot}$. However, the data are somewhat better fit by elliptical disk or binary component models, and we suggest that the emission may be strongly affected by ejecta from the outburst. 
B. F. Lane (1), A. Retter (2), R. R. Thompson (3), J. A. Eisner (4)   ((1) MIT, (2) Penn State, (3) IPAC/Caltech, (4) Caltech)