Variable Stars - RX And
Type Z Camelopardalis Click for lightcurve  These stars show cyclic outbursts, differing from UGSS variables by the fact that sometimes after an outburst they do not return to the original brightness, but during several cycles retain a magnitude between maximum and minimum. The values of cycles are from 10 to 40 days, while light amplitudes are from 2 to 5 mag. in V. AAVSO Alert 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). 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. AAVSO Alert 549: September 1, 2016  Dr. Christian Knigge (University of Southampton) and colleagues have requested AAVSO coverage of the Z Cam dwarf nova RX And in support of Chandra X-ray observations to be carried out via a Target of Opportunity (TOO) triggering when the system is in a suitable outburst. The next outburst of RX And, expected in mid-September, may or may not be well placed for Chandra's schedule, so monitoring may need to continue through more than one outburst before the TOO observations can be triggered. Good coverage of RX And from AAVSO observers this season is essential to ensure seeing when outbursts begin, how they progress and end, and how the system behaves during quiescence. Your observations will be used to decide when to trigger the TOO observations. Please observe RX And beginning now (one to a few times, widely spaced, per night), continuing until the Chandra observations have been carried out and the end of the campaign is announced. Visual and V or CV band observations are requested; other bands are welcome but are not essential. Please report your observations to the AAVSO via WebObs as soon after you make them as possible, especially if you see RX And at visual magnitude 13.5 or brighter. Recently, RX And has ranged between visual magnitudes 11.1 and 14.1; over the years it has been as bright as 10.3 and as faint as 14.8.
Hills Observatory: 1 January 2013 to 16 November 2018
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