YZ Cnc Chandra observing campaign

PTS

AAVSO Alert Notice 565

December 19, 2016

YZ Cnc Chandra observing campaign


Dr. Christian Knigge (University of Southampton) and colleagues
have requested AAVSO coverage of the SU UMa-type dwarf nova YZ Cnc
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.

YZ Cnc has normal outbursts about every 7-10 days, and
superoutbursts about every 100-110 days. The astronomers are
planning to use a superoutburst to trigger the TOO observations.

The last well-documented superoutburst occurred in March 2016, and
a possible superoutburst was observed in June 2016. No
superoutburst was seen in September, but YZ Cnc was just emerging
from conjunction so there were very few observations. The next
superoutburst of YZ Cnc, expected in late December-early January,
may or may not be well placed for Chandra's schedule, so monitoring
may need to continue through more than one superoutburst before the
TOO observations can be triggered. Once the TOO observations have
been triggered, coverage will need to continue through at least one
normal outburst after the Chandra observations have been completed.

Good coverage of YZ Cnc from AAVSO observers this season is
essential; your observations will be used to decide when to trigger
the TOO observations. An AAVSO Special Notice with further
instructions will be issued when the Chandra observations are
triggered, so please be sure to subscribe to the Special Notices.
Subscription to Special Notices (free) is via the Email Settings
tab on your My Account page on the AAVSO website.

Please observe YZ Cnc 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 YZ Cnc at visual magnitude 13.8 or brighter.
Typical normal outbursts reach visual magnitude ~12.0, and
superoutbursts ~11.0-11.3. In recent years at minimum YZ Cnc has
been ~14.6-14.8.

Coordinates (2000.0):  R.A. 08 10 56.65   Dec. +28 08 33.2

Charts: Charts with a comparison star sequence for YZ Cnc may be
created using the AAVSO Variable Star Plotter (VSP) at
https://www.aavso.org/vsp.

Please submit observations to the AAVSO International Database
using the name YZ CNC.

This campaign is being monitored on the AAVSO Observing Campaigns
webpage at https://www.aavso.org/observing-campaigns and is being
followed on the Campaigns and Observation Reports Forum at
https://www.aavso.org/content/yz-cnc-observing-campaign.


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

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