Electronic Telegram No. 3321 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network COMET C/2012 V4 [Editor's note: This replaces the text on CBET 3320 (date correction).] Rob Matson, Newport Coast, CA, U.S.A., reports that he found images of a possible comet in SWAN/SOHO spacecraft images taken in November (his measurements provided below in MPC format, with the first of each two-line set of astrometry showing the R.A. and Decl. and the second line giving the spacecraft coordinates). CK12V040 S2012 11 07.5 19 59.4 -52 56 249 CK12V040 s2012 11 07.5 1 -495068.34 -1260522.88 -518894.899 249 CK12V040 S2012 11 10.5 19 45.2 -46 52 249 CK12V040 s2012 11 10.5 1 -417622.35 -1306343.62 -551398.830 249 CK12V040 S2012 11 11.5 19 41.3 -44 48 249 CK12V040 s2012 11 11.5 1 -391884.74 -1320111.59 -561580.297 249 CK12V040 S2012 11 13.5 19 35.2 -41 12 249 CK12V040 s2012 11 13.5 1 -340679.09 -1345149.81 -580848.200 249 CK12V040 S2012 11 19.5 19 23.7 -35 03 249 CK12V040 s2012 11 19.5 1 -194219.38 -1398698.26 -629304.964 249 Matson computed parabolic orbital elements (T = 2012 Dec. 6, q = 0.75 AU, i = 161 deg) that he circulated via e-mail to solicit ground-based observations to seek confirmation of a possible comet. Terry Lovejoy (Thornlands, Qld., Australia) obtained images through trees and in moonlight on Nov. 29.4 UT (astrometry tabulated below) with a 20-cm reflector that showed a well-condensed comet of diameter 2' and mag about 10. R. H. McNaught also quickly obtained images with the 0.5-m Uppsala Schmidt telescope at Siding Spring, confirming the SWAN object to be a comet, nothing a "spring-onion" appearance with a strongly condensed condensation and a coma of diameter 1'.0 and a 6' tail in p.a. 101 deg. 2012 UT R.A. (2000) Decl. Mag. Observer Nov. 29.39934 19 16 21.76 -29 16 55.3 11.5 Lovejoy 29.42881 19 16 20.04 -29 15 26.2 11.6 " 30.38652 19 15 28.09 -28 29 57.2 11.6 " 30.38694 19 15 28.07 -28 29 56.3 11.5 " 30.39175 19 15 27.83 -28 29 41.8 11.8 " 30.40102 19 15 27.28 -28 29 16.2 11.6 " 30.41491 19 15 26.56 -28 28 36.5 11.7 " 30.41944 19 15 26.33 -28 28 24.3 11.7 " 30.42108 19 15 26.18 -28 28 19.6 10.9 McNaught 30.42221 19 15 26.12 -28 28 16.7 10.9 " 30.42410 19 15 25.99 -28 28 10.5 10.9 " 30.42604 19 15 25.88 -28 28 05.0 10.8 " 30.43043 19 15 25.67 -28 27 52.9 10.9 " Other CCD astrometrists have also made comments on the comet's appearance. Y. Sugiyama (Hiratsuka-shi, Kanagawa, Japan; 0.25-m f/5 reflector; Dec. 1.4) reports a moderately condensed coma of diameter about 30". Images by C. Bell (Vicksburg, MS, U.S.A.; 0.3-m Schmidt-Cassegrain reflector; Dec. 2.0) show a central condensation of diameter 13" and a coma diameter of 40". H. Sato (Tokyo, Japan; 0.51-m f/6.8 astrograph remotely at the RAS Observatory near Mayhill, NM, U.S.A.; Dec. 2.0) found a strongly condensed round coma of diameter 105" in stacked images; he found the total V-band magnitude to be 10.6 as measured within a circular aperture of radius 52".5. A visual observation by A. Hale (Cloudcroft, NM, U.S.A., 0.41-m reflector) on Dec. 1.06 shows a moderately condensed coma of diameter 2'.2 and total mag 9.4 (low altitude; corrected for atmospheric extinction). Maik Meyer, Limburg, Germany, suggested that the orbital elements of comet C/2012 V4 are smilar to those of D/Pons-Gambart (1827 M1). S. Nakano (Sumoto, Japan) then tried linking the orbit but could not find anything where the 1827 residuals are smaller than 0.5 deg; he suggests that if the identification is correct, the period could be 62.1 yr, adding that the comet would have passed 1.27 AU from Saturn on 1830 June 22 and 1.30 AU from Uranus on 1959 May 27. G. V. Williams, Minor Planet Center, writes that an orbit based on just the 2012 observations can have 1/a ranging from about 0.1 to 0, meaning that the period is essentially indeterminate. The solution presented below is based on the assumption that this is a return of D/1827 M1 (Pons-Gambart), a supposition based on the similarity of elements by Williams (and a suggestion made independently by M. Meyer), and that two returns were missed. The 1827 observations are known to be extremely noisy, and this orbit represents seven normal places to about 0.5 deg. The 2012 astrometry and an ephemeris appears on MPEC 2012-X02. Epoch = 2012 Dec. 19.0 TT T = 2012 Dec. 19.7659 TT Peri. = 20.5369 e = 0.948936 Node = 320.8075 2000.0 q = 0.801202 AU Incl. = 136.8482 a = 15.690006 AU n = 0.0158588 P = 62.149 years NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2012 CBAT 2012 December 2 (CBET 3321) Daniel W. E. Green