V838 Mon: a decade long waiting

<p>V838 Mon was discovered in 2002 when it underwent a tremendous outburst. The remnants from this event are a cool supergiant embedded in an expanding molecular shell and a hot B3V secondary. After a few years of a relatively stable light curve, the system experienced a short term dimming in the bluer bands in the end of 2006. Right after recovering from the 70 days dimming, a deep eclipse started in early 2007 which took more than 2 years to reach the minimum light. As with the earlier short dimming, the eclipse is much more pronounced in the bluer bands, indicating that it is related to the hot B3V companion. Right after the onset of this eclipse, the hot companion disappeared completely from the spectrum. Our photometric monitoring of the light curve from the past 13 years implies that the eclipse is still on-going, although we record a steady increase in brightness in the blue bands. Moreover, our simultaneous spectral monitoring reveals a yet weak but steadily increasing H alpha emission, suggesting that the B3V companion is slowly recovering.</p>