Observing Campaign #919: Monitoring needed for PSN J12355230+2755559 (Com) in support of Chandra observations

View here: Details for Monitoring needed for PSN J12355230+2755559 (Com) in support of Chandra observations

Abstract: Dr. Mojgan Aghakhanloo (University of Virginia) informs us that the very interesting SDOR variable PSN J12355230+2755559 (= AT 2016blu) (Com) appears to be going into outburst. Close monitoring (preferably in r or Rc but other bands welcome) is urgently requested to confirm the outburst and magnitude (rising from ~19r to ~17r) in order to trigger Chandra target-of-opportunity observations. OBSERVERS ARE URGENTLY REQUESTED to monitor the target closely throughout the outburst, and then observe nightly for at least 30 days after the target returns to minimum. This target was the subject of AAVSO Observing Campaign 882 (Details for Continued monitoring requested for PSN J12355230+2755559 (Com)).

Justification: For Observing Campaign 882, Dr. Aghakhanloo wrote: "AT 2016blu has experienced at least 19 outbursts from 2012 to 2022. We found that AT 2016blu’s outbursts occur approximately every 113 days. Subsequent to the AAVSO observing campaign’s start in January 2024, at least 6 brightenings were observed by the campaign’s end in July. Recent observations from the Zwicky Transient Facility (ZTF) show it was bright in December 2024, and was above minimum on January 5, 2025, around the time that a brightening event was expected. The light curve of AT 2016blu shows brief, multi-peaked outbursts that sometimes occur before or after the expected periastron time, and as this object’s light curve is complex.

Please update this observing campaign when comp stars are available. Thanks.

Mike

PSN J12355230+2755559

There have been comp stars for this object for a long time. G-scale down to 183 and with B, Rc, and Ic magn. as well.

It is not an easy object for small telescopes.

Jim (DEY)

Curious. When I put in PSN J12355230+2755559 into the VSP with a FOV of 60 arc-min, no comps show up with B,V,I,R either with the name or the coordinates of 12:55:52/+27:55:55. Should I be using a different name? Best regards.

Mike

Perhaps a narrower field? Different (fainter) magnitude limit?

Comp stars appear on the chart for me.

OK. I had mag = 15 limit. Two comps show up - 16.3 and 16.9 - show up when I lower the mag limit. Faint for my system. I was hoping for brighter comps, but I’ll try CR and see how it does. Best regards. Mike

5 min integration in clear gave me CR of 16.8 mag but error of 0.3 mag, higher than the desired 0.1 mag error range, so I doubt that I can help with this since it is at the limits of my 8" SCT system. Best regards.

Mike

Outburst confirmed in accordance with my measures: From 18.5 on 2026/03/16 00:09UT to 17.07 on 2026/03/16 22:26UT (sloan r’)