[ Previous | Next | ADS ]

Optical and X-ray rebrightening in NS X-ray Nova Aql X-1

ATel #10541; A. Meshcheryakov (IKI, Moscow, Russia), I. Bikmaev, E. Irtuganov, N. Sakhibullin (KFU/AST, Kazan, Russia), V. V.Vlasyuk, O. I.Spiridonova (SAO, Nizhnij Arkhyz, Russia), I. Khamitov (TUG, Antalya, Turkey), P. Medvedev, M. N.Pavlinsky (IKI, Moscow, Russia), S. S.Tsygankov (Tuorla Observatory, Finland)
on 29 Jun 2017; 11:07 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Alexander Meshcheryakov (mesch@iki.rssi.ru)

Subjects: Optical, X-ray, Neutron Star, Transient

The current outburst in NS X-ray Nova Aql X-1 has started ~ 28 May 2017, as it was reported earlier (see ATel#10441, #10450, #10452). During optical monitoring campaign of Aql X-1, performed at 1.5-m Russian-Turkish telescope (TUBITAK National Observatory) and 1-m SAO RAS optical telescope (Special Astrophysical Observatory) we report a substantial increase of optical brightness of Aql X-1 in the last few days.
MJD (UTC) Date R,mag Instrument
57901.94 28 May 17.54 1-m SAO RAS
57902.92 29 May 17.55 1-m SAO RAS
57926.90 22 Jun 17.22 1-m SAO RAS
57926.97 22 Jun 17.14 1.5-m RTT150
57927.86 23 Jun 17.18 1.5-m RTT150
57927.90 23 Jun 17.18 1-m SAO RAS
57928.96 24 Jun 17.46 1.5-m RTT150
57930.93 26 Jun 16.70 1-m SAO RAS
57931.90 27 Jun 16.88 1-m SAO RAS
The statistical photometric errors are <1% and ~2% for 1.5-m RTT150 and 1-m SAO RAS, respectivelly. We estimate absolute photometric calibration error as 3%.

Furthermore, during the last several days (time interval 57925 - 57932 MJD) the Swift BAT light curve of Aql X-1 also shows a factor ~2 continuous brightening (from 0.01 to 0.02 counts/sec/cm^2) in the hard X-rays 15-50keV (see https://swift.gsfc.nasa.gov/results/transients/AqlX-1/). Thus, both X-ray and Optical observations indicate enhancement of accretion activity in NS X-ray Nova Aql X-1. We encourage further multi-wavelength observations of the source.