Optical photometry of MAXI J1647-227
ATel #4204; Zurita, C. (IAC); Casares, J. (IAC); Corral-Santana, J. (IAC)
on 22 Jun 2012; 19:16 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Cristina Zurita (czurita@iac.es)
Subjects: Optical, Binary, Neutron Star, Transient
We performed BVRi imaging of the Neutron Star X-ray Binary MAXI J1647-227 (Negoro et al., ATEL #4175; Kennea et al., ATEL #4178, #4192) with the 2.5 m Nordic Optical Telescope, NOT, at the Observatorio del Roque de los Muchachos, La Palma, from 18 to 20th June 2012. The target was calibrated using four different Landolt (1992) standard fields observed during the second night.
Our average BVRi magnitudes are: B=20.80+-0.10, V= 20.08+-0.06, R=19.72+-0.07, i=19.00+-0.10; B=20.23+-0.05, V=19.96+-0.04, R=19.60+-0.06 , i=19.34+-0.06 and B=20.44+-0.02, V= 20.09+-0.02, R=19.67+-0.02, i=19.20+-0.04 on June 18, 19 and 20 respectively.
MAXI J1647-227 is currently ~0.3 mag brighter in B compared to the magnitude reported by Garnavich et al. (ATEL #4179) on June 16th and it shows significant night-to-night variability.
By contrast, the R band magnitude is stable at R=19.7 without any significant variability.
