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Procyon

23 Ian 2017 21:15


Alerta AAVSO #427

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January 23, 2017

Please continue YZ Cnc coverage for Chandra TOO observations

The observing campaign is continuing for the SU UMa-type dwarf nova
YZ Cnc. In AAVSO Alert Notice 565, Dr. Christian Knigge (University
of Southampton) and colleagues requested AAVSO coverage in support
of Chandra X-ray observations to be carried out via a Target of
Opportunity (TOO) triggering when the system was in a suitable
outburst.

Observers have been providing excellent coverage of YZ Cnc - very
much appreciated by Dr. Knigge and colleagues - but unfortunately,
for logistical reasons, Dr. Knigge was not able to trigger during
the recent series of outbursts and superoutburst.

Thus, it is essential to keep up the dense coverage of YZ Cnc that
observers were providing over the past month. Please continue
observing YZ Cnc closely (one to a few times, widely spaced, per
night) until further notice, possibly through the end of the
observing season. Your observations will be used to decide when to
trigger the TOO observations, so they are crucial.

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.

Observers will be informed when the Chandra observations have been
carried out and the campaign ends. 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 Special Notice was compiled by Elizabeth O. Waagen.


Se cere observarea in continuare a stelei variabile YZ Cnc pentru a observa outbursturile, care la randul lor vor fi reobservate de Chandra X-Ray.

Sunt necesare observatiile vizuale, in filtru Johnson V sau nefiltrate cu zeropoint in Johnson V.

Steaua YZ Cnc are outbursturi la 10-12 zile si super-outbursturi la 100-110 zile.

Coordonate: R.A. 08 10 56.65   Dec. +28 08 33.2
VSX:  https://www.aavso.org/vsx/index.php?view=detail.top&oid=4857