TITLE:   GCN CIRCULAR
NUMBER:  37024
SUBJECT: EP240801a: Osservatorio Astronomico Nastro Verde upper limit
DATE:    24/08/04 09:49:22 GMT
FROM:    Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy - MPC Code C82 <osservatorionastroverde@gmail.com>

Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
report: 

We imaged the field of the X-ray transient EP240801a detected at 2024-08-01 09:06:03 (UTC) by Einstein Probe (EP, Zhou et al., GCN 36997; Fu et al., GCN 36998; Li et. al. GCN 36999; Zheng et al, GCN 37000; Aryan et al. GCN 37002; An et al., GCN 37004; Pérez-Fournon et al., GCN 37007; Malesani et al., GCN 37008; Zhu et al., GCN 37010; Moskvitin et al., GCN 37012)with telescope of Nastro Verde Observatory - Sorrento (Naples), Italy. 
Member of: 
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.
AstroCampania Associazione

The observations started at 22:08 UT of 2024/08/01, after about 12 hours after the transient, with clear sky,with principal telescope  SC 0.35 f/10 with focal reduced + CCD Sbig ST10 XME
I took 27 image of 120 sec each. All images are unfiltered, calibrated with masterdark and masterflat,stacked with Tycho Tracker software.
We have not detected any clearly visible sources, up to 19.5th magnitude with clear skies.
 Start                       End         Rlim
20:59:32 UT              21:59:00 UT     19.5

We did not found any optical counterpart.




Magnitudes were estimated with the Gaia DR2 cat. and 
are not corrected for galactic dust extinction.



The message may be cited.