Follows information from ATEL #14939:
"The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has detected a new transient gamma-ray source, Fermi J1623-1752. From data obtained on 2021 Sep 28 (00:00-06:00 UTC),...
A possible counterpart to the LAT transient is the recurrent nova U Scorpii with position offset by 0.18 deg from the LAT position...",
In 2021 Sept. 27 at 22:22 UT I observed U Sco's field and this star was not observed, so my estimate was fainter than 11.5 (using ASAS-3 comps).
Thanks for this post Alex, it’s very interesting! I remember in 2017-2018 there was an observing campaign of this star system but was cancelled because it was reckoned by Brad Schaeffer that it had gone into outburst while behind the sun in early 2018. Only time will tell whether this could have been true, let’s wait and see….unfortunately for me it is now too low in the sky to observe until early January
U Sco 2021 Sept 28.9942 UT <15.1C FRF
U Sco 2021 Sept 28.9984 UT <16.1TG FRF
Using a 60s luminance and green images respectively taken remotely with T70 of iTelescope.net located in Chile.
Image with green filter: https://twitter.com/fidusz/status/1443014491751452678
Lastest observations sent to AAVSO Database are:
2021 Sep. 28.94514 <11.6 Vis. DCMA
2021 Sep. 29.02403 18.6 CV SKA
No bright optical counterpart was detected, as Sokolovsky pointed in ATEL #14941:
I'd like to link this topic with another recent ones regarding U Sco:
https://www.aavso.org/u-sco-2019-campaign-01 (April/September 2019)
I measured it at about mag CV 18.1+/- 0.2 from Chile.
Data are with the AAVSO database.I will keep it in my observing session for as long as it is visible.