This thread will be used for PEP group announcements. Stay tuned!
Tom
Perseus Red/Blue calibration pair
The Perseus Red star is, in fact, a variable. The rate of change is supposed to be slow, so the pair can still be used for second-order extinction calibration. If the rate is really slow it might be possible to establish calibration magnitudes on an annual basis, but that remains to be seen.
Tom
What pair are we talking about here?
\Brian
Tom sez these are HD 21551 = HR 1051 and HD 21552 = sigma Per. Whatever variability there is likely to be microscopic, so the challenge would be to detect the variations all with whatever instrumental setup you have. This would require observing them against at least two other stars to high precision. I’ll bet you can’t do it — but surprise us!
\Brian
Announcements
I have a request. I want this thread to be for actual announcements rather than discussions. If an annoucement provokes a question, please contact me directly.
Tom