56. KX AQUILAE (UG) Range: 12.5-18.4V Position: 19 33 53.66 +14 17 46.4 (J2000, Henden, 19 May 1999) Magnitude: V=18.404 B-V=0.135 (Henden, 19 May 1999) ID RA (2000) DEC X Y N V ERR B-V ERR a) Comparison star sequence 1 19 34 03.7 +14 19 06 145 80 3 11.246 0.378 0.361 0.012 2 19 33 55.0 +14 15 11 19 -155 3 11.589 0.264 0.688 0.105 3 19 34 05.4 +14 21 12 171 206 3 12.059 0.124 1.363 0.115 4 19 33 53.3 +14 16 36 -6 -70 3 12.610 0.030 0.759 0.027 5 19 34 02.7 +14 13 19 131 -267 3 12.769 0.006 0.766 0.009 6 19 34 09.0 +14 22 51 222 305 4 13.329 0.015 0.844 0.007 7 19 33 44.1 +14 20 01 -139 135 4 13.500 0.019 0.703 0.009 8 19 33 42.8 +14 16 55 -159 -51 4 13.768 0.012 0.916 0.012 9 19 34 00.6 +14 17 38 100 -8 4 14.029 0.006 0.874 0.013 10 19 33 34.8 +14 14 21 -276 -205 4 14.642 0.022 1.066 0.010 11 19 34 07.4 +14 17 15 199 -31 4 14.957 0.014 1.203 0.020 12 19 33 51.1 +14 18 48 -38 62 3 15.457 0.050 1.219 0.029 13 19 33 51.1 +14 17 50 -38 4 3 16.015 0.000 1.837 0.015 14 19 33 54.6 +14 17 49 13 3 3 17.139 0.009 1.426 0.013 15 19 33 54.6 +14 17 58 13 12 3 17.804 0.033 1.359 0.027 16 19 33 55.4 +14 18 21 24 35 3 18.936 0.050 1.488 0.253 b) Wide-colour extension for CCD calibration 19 34 10.8 +14 13 29 249 -257 4 13.365 0.013 0.769 0.008 19 34 16.2 +14 14 57 327 -169 4 13.523 0.023 2.202 0.020 19 33 55.4 +14 13 48 25 -238 4 13.900 0.022 2.563 0.025 Notes: 1. Stars 1, 2 and 3 are saturated, and their magnitudes and colours are approximate. They should be used with care. 2. KX Aql has an extremely close red companion located only 2.2 arcsec north. Its magnitude and colour were determined by psf-fitting photometry as V=19.963+/-0.060 and B-V=2.799+/-0.505 3. Stars 13 and 14 are separated by only 8". Their magnitudes were also recomputed with psf-fitting photometry to avoid mutual contamination. 4. There is an AAVSO chart, dated 1973, with a V sequence. Note that only stars with a number in the ID column of the following table are part of the new sequence. Other correspondencies are included for completeness. ID Henden AAVSO V V 1 11.246 11.3 2 11.589 11.5 11.641 11.8 3 12.059 12.2 12.386 12.6 12.448 12.6 4 12.610 12.8 5 12.769 12.6 9 14.029 14.0 5. Varies at minimum between about V=18.3 and V=18.6. 6. KX Aql has not been seen in outburst for at least 20 years. Bruce Sumner 30 July 1999 Revised 5 December 2000