This week we stay with the winter targets that do become visible in the mornings. We have a look at the star GR Mon in the NGC2264 cluster. The star is at a distance of about 570pc and thus belongs to the cluster of young stars situated just north of the Cone nebula.
We show the I-band and R data of the star in the light curve above. The HOYS data covers the last six observing seasons – no new data from this observing season is available yet. One can see that over the years the number of data points has increased, showing the improved coverage of the cluster due to more participants observing regularly.
Similar to many of the young stars, the object varies within a range of about 1.5mag on very short timescales. It might look like noise in the data, but whenever observations in both filters is available one can see that the same pattern of variability is seen. Many of the deep minima (more than one magnitude below the bright state of the star) last only for one day, and are hence most likely caused by small structures in the very inner disk of the system. Hopefully soon, we will start a detailed investigation into the statistics of these kind of sources in our sample to evaluate the structures in the inner accretion disks.