------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 2901 2013 Mar 15 09 59UT 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 E2 (IWAMOTO) Masayuki Iwamoto (Awa, Tokushima-ken, Japan) has discovered a comet (CBET 3439) on three 60-s CCD frames taken with a Canon ESO 5D and Pentax 100-mm f/4 lens as follows: 2013 UT R.A. (2000) Decl. Mag. Observer Mar. 10.83377 20 33 - 3 00 13 Iwamoto 11.84324 20 36 - 2 45 13 " Nakano measured three Iwamoto frames, yielding the improved measures below. Toru Yusa (Osaki, Miyagi-ken, Japan), also obtained images remotely with a 0.25-m f/3.4 hyperbolic astrograph at the iTelescope Observatory near Mayhill, NM, U.S.A. with measures below. Yusa measures a coma diameter of 44" and notes a well-condensed nuclear region. 2013 UT R.A. (2000) Decl. Mag. Observer Mar. 10.83412 20 32 28.19 - 2 58 30.6 14 Iwamoto 11.84359 20 35 59.4 - 2 45 49 " 11.84451 20 35 59.78 - 2 45 53.0 14 " 14.49168 20 45 09.03 - 2 12 26.5 14.5 Yusa 14.49271 20 45 09.24 - 2 12 25.6 " 14.51021 20 45 12.84 - 2 12 12.9 " 14.51123 20 45 13.05 - 2 12 12.1 " 14.51225 20 45 13.24 - 2 12 10.5 " The following preliminary parabolic orbital elements are by G. V. Williams, Minor Planet Center: T = 2013 Mar. 5.5103 TT Peri. = 92.9367 Node = 181.9785 2000.0 q = 1.396249 AU Incl. = 21.9078 The following ephemeris (from the orbital elements on Minor Planet Center) assumes H_8 = 11.5 for the magnitudes: Date TT R. A. (2000) Decl. Delta r Elong. m1 2013 03 15 20 46 53.3 -02 05 58 1.9538 1.4030 43.1 14.4 2013 03 16 20 50 18.3 -01 53 17 1.9543 1.4045 43.2 14.4 2013 03 17 20 53 42.2 -01 40 35 1.9550 1.4062 43.2 14.4 2013 03 18 20 57 04.9 -01 27 51 1.9557 1.4080 43.3 14.4 2013 03 19 21 00 26.6 -01 15 08 1.9565 1.4099 43.4 14.4 2013 03 20 21 03 47.1 -01 02 24 1.9574 1.4120 43.5 14.5 2013 03 21 21 07 06.4 -00 49 40 1.9584 1.4143 43.6 14.5 2013 03 22 21 10 24.5 -00 36 57 1.9595 1.4167 43.6 14.5 2013 03 23 21 13 41.5 -00 24 14 1.9607 1.4192 43.7 14.5 2013 03 24 21 16 57.2 -00 11 33 1.9620 1.4218 43.8 14.5 2013 03 25 21 20 11.8 +00 01 07 1.9633 1.4247 43.9 14.5 2013 03 26 21 23 25.1 +00 13 45 1.9648 1.4276 44.0 14.5 2013 03 27 21 26 37.2 +00 26 21 1.9663 1.4307 44.2 14.5 2013 03 28 21 29 48.0 +00 38 55 1.9679 1.4339 44.3 14.5 2013 03 29 21 32 57.6 +00 51 26 1.9695 1.4373 44.4 14.5 2013 03 30 21 36 05.9 +01 03 54 1.9712 1.4408 44.5 14.6 2013 03 31 21 39 13.0 +01 16 20 1.9730 1.4444 44.7 14.6 2013 04 01 21 42 18.9 +01 28 42 1.9748 1.4482 44.8 14.6 2013 04 02 21 45 23.4 +01 41 01 1.9766 1.4521 44.9 14.6 2013 04 03 21 48 26.7 +01 53 16 1.9785 1.4561 45.1 14.6 2013 04 04 21 51 28.7 +02 05 27 1.9805 1.4602 45.2 14.6 2013 04 05 21 54 29.4 +02 17 34 1.9825 1.4645 45.4 14.6 2013 04 06 21 57 28.8 +02 29 36 1.9845 1.4689 45.5 14.7 2013 04 07 22 00 26.8 +02 41 34 1.9866 1.4734 45.7 14.7 Guy M Hurst