Affiliation
American Association of Variable Star Observers (AAVSO)
Fri, 06/19/2020 - 22:57
Does anyone know if the filters and/or camera used on OC61 have changed since 2013 or have they been the same from 2013-2020?
Thanks,
Bob
Bob:
If you look at the scope description for OC61 on the AAVSONet OC61 page, you will note that the info was updated by SXN on 2/4/2011.
On this basis it is apparent that the camera and filters have been unchanged, at least, since that date.
Ken
The OC61 filters and camera have remained the same since OC61 became available. That said, we've had some difficulty with the filter wheel over the last month or so. You should check the magnitude difference between two comps and compare it with the known value to see if the correct filter is chosen.
The replacement QHY600 camera and filter wheel arrive in New Hampshire this coming week. I'll test them in my lab and then send them down to New Zealand. We should have this improved configuration on-line in July, weather permitting.
Arne
Arne,
The reason I asked is that Ken's recent work to measure TCs for OC61 made me wonder if these numbers could have changed during the time I've been receiving images from this telescope. I realized that some of these targets had field photometry done by you with the one meter scope at USNO Flagstaff. While this field photometry had only three nights of observations compared to the often 10+ nights from Landolt and other standards, it seemed good enough to investigate this matter.
Attached is a spreadsheet of my results. I measured 13 nights from 2014-2020. The TCs seem to fall into two distinct groups: 2014-2015 and 2016-2020. There is a clear change in the TCs between the 2015 and 2016 seasons. Curiously, the TCs from late May, 2020 are similar to those of 2014-2015.
If the camera and filters remained the same, could the change have resulted from something else like recoating the telecope's mirrors or cleaning the filters?
Thanks,
Bob