OJ 287

Coordinates (J2000):

R.A.: 08h 54m 48.9s  Dec.:  +20° 06′ 31”
z = 0.306

Field of view is 15’x15′

GASP suggested stars: 4 10 11

Optical photometry of comparison stars
(UBV: Johnson, RI: Cousins)

Star/Band	U	B	V	R	I
4	15.49 ±0.07	15.01 ±0.06	14.18 ±0.04	13.74 ±0.04	13.28 ±0.04
10	15.00 ±0.05	15.01 ±0.05	14.60 ±0.05	14.34 ±0.05	14.03 ±0.05
11	15.39 ±0.07	15.47 ±0.07	14.94 ±0.04	14.65 ±0.05	14.32 ±0.05
C1	…	…	15.88 ±0.07	15.50 ±0.07	15.08 ±0.07
C2	…	…	16.12 ±0.08	15.66 ±0.08	15.21 ±0.08
2	13.49 ±0.04	13.45 ±0.04	12.80 ±0.04	12.46 ±0.05	12.06 ±0.07

·          Data references:
– stars 4, 10, 11, C1, C2 in VRI:   Fiorucci M. & Tosti G.  1996, A&AS 116, 403
– stars 4, 10, 11 in UB (and star 2 in UBVRI):   Smith P. et al.  1985, AJ, 90, 1184