Object	UT Date	UT	JD	Comp Star	ΔR	σ(ΔR)	R	σ(R)
(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)
BL Lac	2017-07-19	11:17:43	2457953.97064	B	1.361	0.003	13.32	0.02
BL Lac	2017-07-22	11:11:53	2457956.96659	B	1.466	0.003	13.43	0.02
BL Lac	2017-07-23	10:08:26	2457957.92252	B	1.513	0.004	13.47	0.02