Variable Stars - SU UMa
Type SU Ursae Majoris Click for lightcurve SU Ursae Majoris-type variables are characterized by the presence of two types of outbursts called "normal" and "super- outbursts". Normal, short outbursts are similar to those of UGSS stars, while super- outbursts are brighter by 2 magnitudes, are more than five times longer (wider), and occur several times less frequently. During super-outbursts the light curves show superposed periodic oscillations (super-humps), their periods being close to the orbital ones and amplitudes being about 0.2-0.3 magnitudes in V. Orbital periods are shorter than 0.1 days; companions are of dM spectral type. AAVSO Special Notice #413 February 23, 2016 Deanne Coppejans (Department of Astrophysics, Radboud University Nijmegen) requests observations of the dwarf nova SU UMa now in order to determine its status. She and colleagues observed it on 20 February 2016 with the Very Large Array (VLA) and need to know whether it is (was) in outburst. Observations of SU UMa in the AAVSO International Database from around the time of the VLA observations show it to be in quiescence but the observations are sparse and there are no observations between these two observations or since Ripero's one of Feb. 20. Please observe SU UMa and report its status to the AAVSO. Time series are not necessary. If SU UMa is in outburst, please monitorit until it has returned to minimum." AAVSO Alert Notice # 539 March 1, 2016 Ms. Deanne Coppejans (PhD candidate, Radboud University Nijmegen (Netherlands) and University of Cape Town) and colleagues have requested AAVSO observer assistance in monitoring several northern dwarf novae in support of their campaign to observe them with the Very Large Array (VLA) in their ongoing radio jet research. Their research on radio jets in dwarf novae has been discussed in AAVSO Alert Notice 505 (https://www.aavso.org/aavso-alert-notice-505). Observers are asked to keep an eye on RX And, U Gem, YZ Cnc, SU UMa, and Z Cam over the next few months. High-cadence monitoring is not needed; nightly observations are sufficient to determine whether the source is in outburst or quiescence when a VLA observation is taken. In this campaign, the VLA observations are not triggered by the PI, so there is no way to predict when the VLA will observe the sources. Observers will be notified whenever VLA observations are obtained, but no modification of observing instructions is expected. Nightly visual or V observations are requested beginning now and continuing through June 2016.
Hills Observatory: 1 January 2013 to 14 August 2018
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