SU UMa
Type: SU Ursae Majoris
AAVSO lightcurve (2020 )
AAVSO lightcurve (index)
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, 23 February 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, 1 March 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.