This week we have a look at another young star. It is situated in the Sigma-Ori cluster just South of the belt stars in the Orion constellation. The object is called Haro 5-16 or V597Ori and part of the cluster surrounding the bright star Sigma-Orionis. The distance of the cluster is just over 400pc and it has several hundred members, at least 200 of which can be detected in our HOYS data.
The star, like many other young stellar objects, varies on a number of timescales with a range of just over half a magnitude. In the light curve plot we show the last three months of data in the Visual, Red and Infrared filters from the last observing season. One can see that there are smooth variations which are interspersed with short (1day) dipping events. It looks as if for some cases the dips are periodic, but then the period seems to change. These dips are usually caused by denser clumps of material in the inner disk, and orbital periods in this part of the disk are typically about a week, in agreement with the time between consecutive dips. Only a detailed analysis can determine if the consecutive dips are caused by the same clump or not. A task for a research student…