Prediscovery photometry of the M33 microlensing event candidate AT 2021abdj
ATel #14977; Filipp Romanov (amateur astronomer, Russia)
on 17 Oct 2021; 12:08 UT
Credential Certification: Kirill Sokolovsky (kirx@scan.sai.msu.ru)
Subjects: Optical, Microlensing Event
I observed the field of galaxy M33 remotely using 0.61-m f/6.5
corrected Dall-Kirkham robotic telescope (Lane, 2018, RTSRE, 1,
119) of Burke-Gaffney Observatory (Saint Mary's University in
Halifax, Nova Scotia, Canada). The 900 seconds exposure images were
taken between 2021-09-14 and 2021-10-16 through Astrodon Luminance
(UV/NIR blocking) filter. All these images clearly show the object
reported in ATel #14976. I measured its magnitude comparing to
V-band magnitudes of nearby stars from
Massey et al. (2016, AJ, 152, 62):
2021-09-14 03:34 CV = 19.1 +/- 0.1
2021-09-15 02:31 CV = 18.9 +/- 0.1
2021-10-03 02:07 CV = 19.2 +/- 0.2
2021-10-05 06:12 CV = 19.6 +/- 0.2
2021-10-06 01:28 CV = 19.7 +/- 0.2
2021-10-09 03:18 CV = 19.7 +/- 0.3
2021-10-12 00:33 CV = 19.9 +/- 0.3
2021-10-16 01:28 CV = 20.2 +/- 0.4
Dates are indicated in UTC and for the middle of the exposures.
The first and last images are available here
