This week we bring a timely reminder of our upcoming observing campaign for the Sigma-Ori target field. The campaign will start 23.11.2024 and last for 2 weeks until 8.12.2024. The aim is to observe the field once an hour in all filters available. The two weeks are centred around the New Moon period with the field at it’s highest point at about 1am local time in most time zones. The next New Moon period would probably be more convenient, as the target would be at its highest point two hours earlier, but this coincides with the Christmas and New Years period, and we tried to avoid that.
The reason for the high cadence campaign is the star with the light curve shown above. We looked at this one about 9 months ago in week 268. In essence the light curve looks like a beating pattern between two similar frequencies. However, due to our typical cadence of one day, it is not certain if the two periods are around two days or 16 hours. Both of these would create the pattern visible in the above plot. Thus, data points every hour will ensure we know the right set of periods. Once we do, we can use the beat period (~25d) to work out the two individual periods accurately. This will then hopefully help to work out what causes this kind of light curve.