Optical observations of MAXI J1631-479
ATel #12438; Min-Su Shin (Korea Astronomy and Space Science Institute), Jae-Woo Kim (KASI), Seo-Won Chang (Australian National University/OzGrav), Chung-Uk Lee (KASI), Seung-Lee Kim (KASI)
on 28 Jan 2019; 05:27 UT
Credential Certification: Min-Su Shin (msshin@kasi.re.kr)
Subjects: Optical, Black Hole, Transient
Referred to by ATel #: 12504
We have conducted optical follow-up observations of the 2 degree by 2 degree field around MAXI J1631-479 (Kobayashi et al. ATel #12320; Miyasaka et al. #12340; Russell et al. #12396; Onori et al. #12418; Negoro et al. #12421) by using the KMTNet telescopes (1.6m diameter telescopes at three sites; Kim et al., JKAS, 49, 37, 2016). We do not find any significantly variable objects around the radio position reported by ATels #12396. The field already has the DECaPS and VPHAS+ data which can be compared to our newly acquired images. The nearest object from the radio position is VPHASDR2 J163114.1-474822.7 which is 18.3 mag in i-band. The flux of the VPHAS+ object is R ~ 19.1 mag and I ~ 18.0 mag in our recent
observations using the KMTNet telescopes at SSO, SAAO, and CTIO over the time period from 2019-01-23 18:00 to 2019-01-24 09:10 (UT). We used the ATLAS REFCAT2 (Tonry et al. 2018) for photometric calibration.
