AAVSO Alert Notice 581 announces an observing campaign on the bright (V = 4.23) and very unusual eclipsing binary HD 148703. This campaign begins immediately - coverage is needed starting now for eclipses occurring June 11 and June 14. Please see the notice for details, observing instructions, and chart instructions.
Many thanks, and good observing!
Elizabeth Waagen, AAVSO HQ
The alert notice provides specific comp stars for photometry.
For those of us doing wide field DSLR photometry who don't yet have good transformation coefficients for use with VPHOT or TA, other than the comp stars specified, is there a recommendation for additional sequence stars suitable for ensemble photometry?
I may be answering my own question here but since the alert notice talks about establishing out of eclipse baselines for each observer, is the request actually for TG rather than V in the absence of a non-ensemble approach to photometry?
I imaged HD 148703 last night and will do so as much as possible this week, weather permitting.
Sadly, I was clouded out on both nights when the primary and secondary eclipses were underway.
I made two DSLR observations (not submitted) during out of eclipse times.
I see that some visual observations have been submitted.