Affiliation
American Association of Variable Star Observers (AAVSO)
Wed, 04/10/2019 - 20:47
I'm a visual observer with a few YSO's in my program. Last night I noticed that RR TAU seemed to be fading and brightening over a very short 'period' less than 10-30 seconds or so from ~12.0-~12.5 vis (very roughly!). It may have simply been a seeing effect, but I didn't notice a like effect in any of the comp stars in the field. I paid particular attention to the 118 and 121. I suppose a color effect on seeing could have caused this difference, but has anyone noticed anything of the sort with RR TAU or other UXORS/YSOs? Has there been any high cadence time series photometry done on UXORs or other YSO's for high or low states?
I have a 26 year visual data set on RR Tau, and have no record of any flickering phenomenon noted (by me) in that time. Doesn't mean it can't happen though. The change in brightness of RR Tau is pretty dramatic, so why should ultra-short term mico-variations be ruled out?
Gary
Thanks for responding. 26 years, wow. Yes, it is an interesting variable observe; I never quite know what to expect. Unfortunately, the treeline to the west of my observing location cuts out the sky at ~30 degrees altitude. I may have to wait until fall to observe it again...
Yes, I have seen the same thing on one occasion, with CQ Tau (nearby!) going through a 0.9m fade over the course of approx. 20 seconds. Not seen this behaviour before or since, having been observing it since 1976.