Alert Notice 771: V1117 Her in deep fade again

March 11, 2022

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
- Campaigns and Observation Reports: https://www.aavso.org/v1117-her-fading-01

- Young Stellar Objects (YSO): https://www.aavso.org/v1117-her-fading-01

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AAVSO Young Stellar Object (YSO) Section leader Michael Poxon (Great Plumstead, Norfolk, UK) requests coverage of the YSO V1117 Her beginning immediately.

He writes: "The anomalous YSO (possibly debris-disc object) V1117 Herculis is at a deep minimum of visual magnitude 15.1 as of 2022 March 9.45 UT, from observations by AAVSO member John Pickett. Observations, in a variety of filters - visual observations included of course - are requested to see what happens next. Deep minima of this object have tended to occur at semi-regular intervals of about 400 days but the last comparable minimum drawn from the AAVSO light curve was only about 100 days ago, so this may indicate new processes are taking place in the circumstellar environment."

"Observations in the B and I bands are especially welcome. V band photometry is encouraged, and visual observations are welcome. Observations two-three times per night are requested (and once per night between episodes of activity)." V1117 Her has a range of approximately V = 12.3 - <13.9.

Coordinates (2000):  RA 16 39 06.43  Dec. +09 47 55.3 (from VSX entry for V1117 Her)

Charts: Finder charts with comparison stars for V1117 Her may be created using the AAVSO Variable Star Plotter (VSP).

Submit observations: Please submit observations to the AAVSO International Database using the name V1117 HER.


This AAVSO Alert Notice was compiled by Elizabeth O. Waagen using material provided by Michael Poxon.

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