179 V391 SCUTI (UG:) Range: 13.8-21 (from DSS images) Position: 18 28 06.60 -15 54 44.0 (J2000, from .dat file) Magnitude: V=13.789 B-V=1.807 (from .dat file) ID RA (2000) DEC X Y N V ERR B-V ERR a) Comparison star sequence 1 18 28 24.0 -15 52 56 251 108 1 10.861 9.999 0.483 9.999 2 18 28 14.7 -15 55 57 117 -73 1 11.203 9.999 0.580 9.999 3 18 28 17.4 -15 51 53 156 171 1 11.726 9.999 0.713 9.999 4 18 27 48.7 -15 57 12 -259 -148 1 12.385 9.999 0.772 9.999 5 18 28 02.8 -15 55 06 -54 -22 1 12.643 9.999 0.424 9.999 6 18 28 05.3 -15 52 27 -19 137 1 13.262 9.999 0.670 9.999 7 18 27 55.9 -15 54 36 -155 8 1 13.561 9.999 0.761 9.999 8 18 28 05.8 -15 54 58 -11 -14 1 13.984 9.999 0.706 9.999 9 18 28 07.2 -15 55 11 8 -27 1 14.239 9.999 0.462 9.999 10 18 28 07.6 -15 56 03 14 -79 1 14.715 9.999 0.839 9.999 11 18 28 05.8 -15 55 18 -11 -34 1 15.122 9.999 0.956 9.999 12 18 28 10.9 -15 55 12 61 -28 1 15.455 9.999 0.808 9.999 13 18 28 10.0 -15 54 35 49 9 1 16.248 9.999 0.953 9.999 14 18 28 08.1 -15 55 00 22 -16 1 16.865 9.999 1.349 9.999 15 18 28 09.2 -15 54 15 38 29 1 18.000 9.999 1.421 9.999 b) Wide-colour extension for CCD calibration 18 28 20.9 -15 58 05 206 -201 1 12.533 9.999 0.339 9.999 18 27 51.1 -15 54 36 -224 8 1 13.502 9.999 0.415 9.999 18 27 59.4 -15 56 23 -104 -99 1 14.602 9.999 2.396 9.999 18 27 52.3 -15 50 58 -207 226 1 15.198 9.999 2.537 9.999 Notes: 1. The first four stars are saturated, and their magnitudes and colours are approximate. They should be used only for guidance until accurate magnitudes are determined. 2. Downes, Webbink and Shara, in their 1997 catalogue, consider this variable to be lost and not able to be identified. However precessing the discovery position (P. Maffei, IBVS, 12 April 1975, object M64) to J2000 reveals that M64=GSC 6266-2259=V391 Sct. 3. Examination of this star on the available Schmidt pixel imagery shows that on three date in three separate years, namely 1982, 1984 and 1986, V391 Sct was at maximum at about magnitude 14.0. However on Palomar red and blue exposures taken on 23 August 1952 V391 Sct is very faint, and is estimated at 21R and <21B. 4. All images reveal that V391 Sct is the northern component of a very close double star, with the southern component having an estimated magnitude of V=15.8 and B=17.6 and a separation of approximately 4 arcsec SW of V391 Sct. 5. The evidence suggests that Maffei's estimated minimum of I=17.0 actually refers to the southern companion, and not V391 Sct itself. The double nature of V391 Sct would most likely not have been resolvable on his imagery. 6. There are three bright stars near the edges of this field that were not included in the photometry, but which have reliable Tycho-2 magnitudes. They are: a) 18h 28m 29.8s -15d 48' 14" V= 8.90 +/-0.02 b) 18h 27m 41.3s -15d 56' 52" V= 9.61 +/-0.04 c) 18h 28m 27.3s -15d 59' 38" V=10.44 +/-0.06 Bruce Sumner