Optical outburst of Aql X-1 detected by Murikabushi telescope
ATel #15056; M. Niwano, R. Hosokawa, N. Kawai (TokyoTech), T. Horiuchi, H. Hanayama (NAOJ) report on behalf of the MITSuME collaboration
on 23 Nov 2021; 05:34 UT
Credential Certification: Katsuhiro Murata (murata@hp.phys.titech.ac.jp)
Subjects: Optical, Binary, Neutron Star, Transient
We monitor the recurrent neutron star low-mass X-ray binary Aql X-1 = V1333 Aql in optical wavelength. The last outburst in optical and X-ray of Aql X-1 was reported in Mar 2021 (Atel #14437, #14563, H.Negoro & K.Seino, X-ray-star:806). On Nov 17, a new X-ray outburst was reported in the public mailing list (Komachi, X-ray-star:845). Here we report an optical brightening of this object by the optical three color (g', Rc, and Ic) CCD cameras attached to the 105 cm Murikabushi telescope of Ishigakijima Astronomical Observatory, Okinawa, Japan.
We obtained the preliminary magnitudes of Aql X-1 as follows: g'=18.14+/-0.06, Rc=17.43+/-0.03, Ic=16.90+/-0.08 on 2021-11-17 (MJD 59535.43), g'=18.27+/-0.05, Rc=17.45+/-0.02, Ic=16.96+/-0.07 on 2021-11-18 (MJD
59536.44), g'=17.96+/-0.04, Rc=17.25+/-0.02, Ic=16.77+/-0.08 on 2021-11-20 (MJD 59538.44), and g'=17.83+/-0.05, Rc=17.14+/-0.02, Ic=16.72+/-0.07 on 2021-11-21 (MJD 59539.45).
We used PS1 catalog for flux calibration. The magnitudes are expressed
in the AB system. The images were processed by the MITSuME GPU reduction pipeline (Niwano
et al. 2021, PASJ, 73, 1, 4-24; https://github.com/MNiwano/Eclaire). We will continue simultaneous multi-color observation with the MITSuME telescope. Multiwavelength follow-up observations are encouraged.
