Alert Notice 693: V582 Mon monitoring requested

Note: Please continue coverage of V582 Mon until further notice.  -  Elizabeth O. Waagen, 1 February 2021

January 24, 2020

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
  -   Campaigns and Observing Reports:
  -   Young Stellar Objects:

AAVSO Young Stellar Objects (YSO) Section leader Michael Poxon requests, on behalf of Dr. William Herbst (Wesleyan University), AAVSO observers' assistance in monitoring the eclipsing T Tau system V582 Mon (KH 15D).

Poxon writes: "The young system V582 Mon, also known as KH 15D, is an object that now needs photometric monitoring by anyone with the capability. It is not for the faint of heart (varies between I mags 14 and 18, and a few seconds of arc from a 7m star!). Bill's team have monitored it religiously for decades, mostly with the 1.3m telescope at CTIO that was part of the SMARTS consortium. Unfortunately, that resource is no longer available and the system is not being regularly monitored anywhere by anyone, as far as he knows.

"Vital statistics and information are given at the Wikipedia page on the object:

"[Dr. Herbst] says: 'We can use data on any and all nights. It varies on a time scale of hours, not minutes or seconds, so one observation per night (in multiple colors, if possible) per site is fine. I can provide info and advice on data reduction if anyone obtains data.' Prof. Herbst can be contacted at

"The need for monitoring is particularly urgent in the next month or two, since his team have been assigned time on Gemini South to obtain infrared spectroscopy of the star (sometime between February 1 and April 30). And, it has entered a new and interesting phase in which one star of the binary is currently emerging from behind the edge of a circumbinary ring. As it does so, the light from that star acts as a proble of the ring structure, which is a likely region of planet formation."

Please make nightly observations of V582 Mon from now through May 15. The V range of V582 Mon is 15.1-21.5.

Coordinates: R.A. 06 41 10.30  Dec. +09 28 33.6  (2000.0)

AAVSO finder charts for V582 Mon with comparison stars selected by Dr. Herbst may be created using the AAVSO Variable Star Plotter (VSP). There are only two comparison stars. So that these comp stars may be seen clearly on the chart, observers should select "do not display other variables" when creating their chart(s).

Please submit your optical observations to the AAVSO International Database using the name V582 MON.

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen using text supplied by Mike Poxon.

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