------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 2333 2007 May 06 19.26UT 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/2006 WD4 (LEMMON) Ernesto Guido and G. Sostero, Italy, advise us that they have detected that this object found at Mt. Lemon and reported on MPEC 2006-W61 shows cometary features. The original discovery was made on: 2006 UT R.A. (2000) Decl. Mag. Nov. 20.32650 3 32 32.53 +28 02 22.0 20.3 They have sent us a picture obtained on 2007 April 30.80UT and secured on the Rent-a-Scope Observatory at Biggera Water, Queensland, Australia. Eleven unfiltered exposures of 60 second each were stacked and obtained with a 0.15-m f/5 Maksutov-Newtonian plus SBIG ST10E CCD. They add in CBET 952 that the exposures revealed the presence of a spiral-like symmetric coma, spanning almost 20 arcsec, from PA 240 deg to PA 30 deg (in a counterclockwise direction); the total mag was close to 14.2 and that of the condensation 15.3-15.4. Astrometry by Guido and Sostero follows: C2007 04 30.79974 00 50 29.60 -10 23 19.6 15.3 N EJ012E26 C2007 04 30.80592 00 50 30.33 -10 23 22.1 15.4 N EJ012E26 C2007 05 02.79568 00 54 35.10 -10 25 11.2 15.4 N EJ012E26 C2007 05 02.79971 00 54 35.68 -10 25 10.4 EJ012E26 Orbital elements and ephemeris by Brian Marsden: Epoch 2007 Apr. 10.0 TT = JDT 2454200.5 T 2007 Apr. 28.39514 TT MPC q 0.5912066 (2000.0) P Q z +0.0017013 Peri. 292.69278 +0.33342137 -0.88153768 +/-0.0000076 Node 226.79078 -0.60469368 -0.47196641 e 0.9989942 Incl. 152.70380 -0.72330888 -0.01179081 Date TT R. A. (2000) Decl. Delta r Elong. Phase m1 2007 04 30 00 49.15 -10 20.9 0.970 0.592 34.8 76.0 14.2 2007 05 01 00 50.84 -10 23.9 0.931 0.594 35.4 79.3 14.1 2007 05 02 00 52.80 -10 25.4 0.892 0.597 36.0 82.6 14.0 2007 05 03 00 55.06 -10 25.0 0.852 0.600 36.4 86.0 13.9 2007 05 04 00 57.68 -10 22.7 0.813 0.604 36.8 89.5 13.9 2007 05 05 01 00.70 -10 18.0 0.773 0.609 37.1 93.0 13.8 2007 05 06 01 04.19 -10 10.6 0.733 0.615 37.3 96.5 13.7 2007 05 07 01 08.23 -10 00.1 0.693 0.621 37.3 100.1 13.6 2007 05 08 01 12.89 -09 45.9 0.653 0.629 37.2 103.9 13.6 2007 05 09 01 18.29 -09 27.3 0.614 0.636 36.9 107.7 13.5 2007 05 10 01 24.57 -09 03.6 0.575 0.645 36.4 111.7 13.4 2007 05 11 01 31.89 -08 33.7 0.536 0.654 35.7 115.8 13.3 2007 05 12 01 40.44 -07 56.2 0.498 0.663 34.6 120.1 13.2 2007 05 13 01 50.49 -07 09.5 0.461 0.674 33.2 124.7 13.1 2007 05 14 02 02.32 -06 11.5 0.426 0.684 31.4 129.6 13.0 2007 05 15 02 16.33 -04 59.6 0.392 0.695 29.2 134.9 12.9 Congratulations to Ernesto and Giovanni on this detection! Guy M Hurst