AAVSO: American Association of Variable Star Observers

Proposal #379

Proposer (36365) Tom Love (tlove@outlook.co.nz) obscode: LTOC
Assigned To(3663) Dirk Terrell
Date SubmittedJuly 8, 2023

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.

Target RA (H.HH) Dec (D.DD) Magnitude Telescope Observation Frequency Expiration Date Proprietary Term
IO Nor 16.374720 -48.59890 16.0–11.0 BSM_S 3 June 1, 2025 No
GU Sgr 18.404450 -24.25720 15.0–10.0 BSM_S 3 June 1, 2025 No
V653 Sco 17.821020 -38.77870 17.0–12.0 BSM_S 3 June 1, 2025 No


(36365) Tom Love — July 11, 2023, 9:33 a.m.

Hi - I am afraid I made a mistake with one of the targets. V653 Sgr is incorrect - it should be V653 Sco, which is at (2000.0) RA 17.82102 Dec -38.7787

(4726) Kenneth Menzies — July 12, 2023, 4:45 p.m.

Added V653 Sco. Removed V653 Sgr.

(4726) Kenneth Menzies — July 12, 2023, 4:58 p.m.

Committed to BSM_S.

Comments on this proposal are closed.