Proposal #379

This proposal is for followup observation of 3 R Cor Bor stars undergoing a dimming phase. The number of known R Cor Bors has expanded over the past decade or so, but monitoring of them (other than of the archetype star) is still very infrequent. Other than R Cor Bor itself, which is well observed by amateurs, there are at least three known Southern R Cor Bors currently in a dimming phase that are not well observed, and especially are not well observed in colours other than V: IO Nor, V653 Sgr and GU Sgr. Data for these have been taken in Australia by Andrew Pearce and uploaded to the AAVSO database.

However this is the wet season in West Australia, and observations have come to a halt. This proposal is for observations with a cadence of around 3-4 days, in BVRI. This class of stars pulsates, so ongoing monitoring once they have returned to peak brightness has the potential to reveal the underlying pulsation frequencies. Therefore, the proposal is to continue monitoring of these stars for 12 months from now, allowing for a period of followup once they return to maximum brightness. Given the vagaries of weather at different sites, the data from this proposal are likely to be a good complement to the observations that Andrew Pearce is conducting of these objects from Perth.