Proposal #634

My 30 min. drive time away observing site is in jeopardy by the state of Virginia. Astronomy is not an approved activity at the wildlife management area now.

I have since 2017 Nov 11 monitored TW Cap with transformed magnitudes from DSLRs (BVRc) and mostly with CCDs (BVRcIc). I have good light curve coverage on all observing seasons since 2017. TW Cap' period is quite variable and there are light curve shape variations. I have over the years accumulated an O-C library of published times of maxima starting with Tsesevich who first observed it in 1917. It is classifed as CWA in VSX. Could be a RVA and go the way of reclassification as one of my other fav for CW stars, RX Lib.

Visual observations I made from 1978 to 1982 were publlshed in the JAAVSO V.4.

I have 3 and 4 color well sampled light curves for over 60 cepheids, most over 10d periods since 2017. I have new epochs and periods for all. Much of this associated photometry is in the final stages of prepation for sending to the JAAVSO. TW Cap will get its own paper, analyzing the "new" photometry I have made by observing season and the O-C diagram since 1917.

Ideally four-color B, V, Rc, and Ic every night till the end of the observing season would produce the best results. The amplitude is large enough that observations may be made at relatively air mass are usable. Alternatively, B, V, Ic and at a minimum B, V filters.

Somewhere around 2026 January after solasr conjuction we can review and resubmit the proposal as required.

Thanks, James DeYoung (DEY)