------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 2929 2013 Jly 14 19.00UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074 INTERNET: GUY@TAHQ.DEMON.CO.UK Backup: gmh@wdcc1.bnsc.rl.ac.uk WORLD WIDE WEB http://www.theastronomer.org ------------------------------------------------------------------- COMET C/2013 N4 (BORISOV) Gennady Borisov, Sternberg Astronomical Institute, reports the discovery of a comet on CCD images taken with a 0.2-m f/1.5 astrograph on 2013 July 8.99UT. It showed a coma of diameter of about 20". 2013 UT R.A. (2000) Decl. Mag. Observer July 8.98688 5 36 12.45 +45 34 24.4 16.8 Borisov 9.00769 5 36 19.67 +45 34 21.3 16.8 " 10.00148 5 41 38.80 +45 29 14.0 16.8 " 10.02778 5 41 47.66 +45 29 05.9 16.8 " Follow-up 180-s exposures taken by I. Ionov with the Crimean 0.32-m f/4 Newtonian reflector on 2013 July 11.0 show a large, diffuse, round coma of diameter 1'.7 and total mag near 13.5 but with no visible tail. Peter Birtwhistle (Great Shefford, England; 0.40-m f/6 Schmidt-Cassegrain reflector; July 12.1) finds a central condensation of diameter 6" surrounded by a faint coma of size 25" x 35" (and total mag 15.2), elongated in p.a. 135/315 degrees; the magnitude was 15.2 as measured in an aperture of diameter 34" and 16.1-16.5 as measured in an aperture of diameter 12".8. Alan Hale, Cloudcroft, NM, U.S.A., reports total visual mag 13.5 (corrected for atmospheric extinction) with a diffuse 0'.6 coma as seen vaguely at low altitude with a 0.41-m reflector on July 12.44. Gareth Williams, Minor Planet Centre reports elements/ephemeris: T 2013 Aug. 20.13153 TT MPC q 1.2255238 (2000.0) P Q Peri. 140.82818 -0.30897329 -0.87792119 Node 322.56754 +0.64867165 +0.08673051 e 1.0 Incl. 36.99697 +0.69552901 -0.47088449 >From 39 observations 2013 July 8-13. Ephemeris: Date TT R. A. (2000) Decl. Delta r Elong. m1 2013 06 13 03 26 38.9 +43 19 38 2.3758 1.6020 31.6 15.9 2013 06 28 04 38 17.0 +45 35 39 2.2393 1.4701 31.4 15.4 2013 07 06 05 20 13.9 +45 44 43 2.1825 1.4078 30.7 15.2 2013 07 12 05 52 21.0 +45 16 21 2.1479 1.3656 30.0 15.0 2013 07 13 05 57 42.0 +45 08 33 2.1428 1.3590 29.9 15.0 2013 07 14 06 03 02.4 +44 59 53 2.1379 1.3525 29.7 15.0 2013 07 20 06 34 41.1 +43 49 29 2.1125 1.3165 28.8 14.8 2013 07 28 07 15 03.2 +41 28 58 2.0895 1.2768 27.4 14.7 2013 08 12 08 22 13.9 +35 07 34 2.0768 1.2320 24.8 14.5 SUPERNOVA 2013cw IN NGC 6211 (L. COX ET. AL.) 2013cw May 29.35 16 41 27.17 +57 47 05.0 16.9 3.9"W 3.2"N Dave Balam, Dominion Astrophysical Observatory, National Research Council of Canada et. al., report spectrogram obtained on June 3.34 UT with the 1.82-m Plaskett Telescope of the National Research Council of Canada, shows it to be a type-Ia supernova near maximum light. SUPERNOVA 2013cv The second line of this object's announcement on E2928 should read 2013cv and not 2013cy. Guy M Hurst