Aql X-1: indicators of optical outburst in 2022
ATel #15401; V. V. Vlasyuk, O. I. Spiridonova, A. S. Moskvitin, O. A. Maslennikova (Special Astrophysical Observatory of the Rus. Ac. Sci.)
on 27 May 2022; 12:47 UT
Credential Certification: Alexander Moskvitin (mosk@sao.ru)
Subjects: Optical, Binary, Transient
Our team informs about presence of new outburst indicator for the Soft X-ray Transient (SXT)
Aql X-1. Most of our data were taken with the 1-m SAO RAS optical telescope, some additional
measurements were performed with our 0.5-m RC reflector. According to our preliminary results
in R-band, it's brightness increased since end of April. Our estimate of brightness of Aql X-1
optical counterpart in R-band in April, 27th was about 18.35mag. Meanwhile, our last night
observations with 1-m reflector (May 26/27) gave R-magnitude as high, as 17.20mag (accurate
epoch 59725.96 MJD).
Typical errors of brightness estimates are about 0.03-0.04 mag and should be decreased after
more accurate data reduction and correct extraction source image in crowded field.
Further observations of Aql X-1 in X-ray, UV, Optical, IR and Radio ranges are highly
encouraged.