Special Notice #323: Observations of BB Dor requested

January 14, 2013: Dr. Boris Gaensicke (Warwick University), who is the coordinating PI on the large observing campaign underway to observe cataclysmic variables with the HST Cosmic Origins Spectrograph (see AAVSO Alert Notice 471 and follow-up AAVSO Special Notices as listed on the AAVSO Observing Campaigns page), is requesting observations tonight and over the next few nights of the novalike variable BB Dor. He writes: "it appears that the SW Sex star BB Dor is in a deep low state, and that would make it a very interesting target for HST ultraviolet observations: during the normal high state, it is impossible to see the white dwarf in the system, as it is shielded by the accretion disk - however, in a low state, there is a good probability that most of the disk is gone...

"If you have a chance, could you get a few more observations of BB Dor to see how stable it is settled at V~19? If it looks fast asleep, we would proceed with planning the HST observations..."

CU Vel takes priority over BB Dor, however, if you have time/opportunity to observe only one target (see AAVSO Special Notice #322 for info on CU Vel observations).

Coordinates for BB Dor: 05 29 28.64 -58 54 46.6 (2000.0)

Charts may be created using VSP. Please submit observations as soon as possible to the AAVSO International Database using the name BB DOR.

This AAVSO Special Notice was compiled by Elizabeth O. Waagen.


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