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AAVSO Special Notice

Special Notice #429: V694 Mon (MWC 560) spectroscopy requested

May 2, 2017: Further to AAVSO Alert Notice 538, the campaign from 2016 on V694 Mon (MWC 560) has been continued, but with different requirements. Photometry is no longer specifically requested on a regular basis (although ongoing observations that do not interfere with other obligations are welcome). Spectroscopy on a cadence of a week or two is requested to monitor changes in the disk outflow. V694 Mon is presently nearing opposition, but the request for spectroscopy continues until further notice.

Special Notice #428: YZ Cnc Chandra observing window delayed

January 25, 2017: The beginning of the observing window for the Chandra TOO observations of the SU
UMa-type dwarf nova YZ Cnc that are the focus of AAVSO Alert Notice 565 and AAVSO Special Notice #427 has been delayed.

Principal Investigator Dr. Christian Knigge (University of Southampton) informs us that Chandra Mission Planning has informed him that the beginning of the Chandra-observable window for YZ Cnc has been delayed until 2017 February 5.

Special Notice #427: Please continue YZ Cnc coverage for Chandra TOO observations

January 23, 2017: 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.

Special Notice #426: Blazar CTA 102 (4C 11.69) in very bright outburst

December 1, 2016: The blazar CTA 102 (4C 11.69) has been in an active state in gamma-ray and optical wavelengths since 2015. During 2016, it has had numerous flaring episodes, particularly since late October. It is presently in an unprecedentedly bright optical state, and showing substantially increased emission in gamma-ray and near-infrared wavelengths.

Special Notice #425: FO Aqr XMM-Newton observations scheduled

November 9, 2016: Further to AAVSO Alert Notice 545, time series observations of the intermediate polar cataclysmic variable FO Aqr are requested to provide simultaneous coverage of XMM-Newton observations scheduled for 2016 November 13 19:43 UTC to November 14 8:13 UTC.

Special Notice #423: RX And observations needed urgently now

October 11, 2016: Further to AAVSO Alert Notice 549, observations of the dwarf nova RX And are urgently requested immediately. The system *may* be going into outburst, and confirmation is essential in order to know whether to trigger ToO observations with Chandra and other instrumentation.

Special Notice #422: GDS_J1701281-430612 HST observations scheduled

September 30, 2016: Further to AAVSO Alert Notice 551, Dr. Mark Reynolds (University of Michigan) informs us that the cataclysmic variable GDS_J1701281-430612 will be observed by the HST/COS on

07 Oct 2016 at 00:23:57 UT

Special Notice #421: SN 2016gkg - Unusual Type-II Supernova in NGC 613 (Scl)

September 22, 2016: SN 2016gkg (announced as AT2016gkg) was discovered by Victor Buso (Rosario, Argentina) on 2016 September 20.2484 UT at CCD magnitude (clear filter) 17.6 +/-0.5, rising to 14.5 +/-0.2 on Sep. 21.1398. His discovery was reported to the Transient Name Server by Sebastian Otero (Buenos Aires, Argentina). It was confirmed by ASAS-SN on Sep. 21.29 UT (B. Nicholls (Mt.

Special Notice #420: OJ 287 very bright and Subscription reminder

September 13, 2016

OJ 287

S. Zola (Jagiellonian University) et al. (ATel #9489) report that the BL Lac object OJ 287 has emerged from conjunction optically very bright and increasing in brightness, according to their observations made at Mt. Suhora Observatory in August and September 2016.

Their observations and recent observations of this blazar in the AAVSO International Database include:

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