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Circular No. 8772 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) CBAT@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304 Phone 617-495-7440/7244/7444 (for emergency use only) COMET C/2006 M4 (SWAN) C. E. Woodward and M. S. Kelley, University of Minnesota; and P. M. Hinz, M. A. Kenworthy, and W. F. Hoffman, Steward Observatory, University of Arizona, report the discovery, in 10.55-micron narrow- band (FWHM = 0.97 micron) images obtained with the 6.5-m MMT telescope (+ MIRAC4-BLINC) and adaptive optics (AO) secondary on Nov. 7.08 UT, of a detached-coma feature located 3".4 from the nuclear condensation of comet C/2006 M4 (corresponding to 2700 km at a geocentric distance of 1.10 AU) in p.a. approximately 43 deg. Aperture photometry, derived from images obtained through thin cirrus, with the AO system locked on the diffuse comet nucleus in a 3".1 circular beam, yields 10.55-micron fluxes of 9.5 +/- 0.5 Jy for the nuclear condensation and 4.1 +/- 0.4 Jy for the detached-coma feature. The detached-coma feature is elongated along the same position angle, with a spatial extent of approximately 3" by 1".5. The nucleus was unresolved in the diffraction-limited images (FWHM = 0".4) and appears to be embedded in a diffuse coma (FWHM = 0".7). Further mid-infrared observations are encouraged. COMETS C/2006 R3, C/2006 R4, C/2006 S7-S9 (SOHO) Several additional apparent comets have been found on SOHO website images (cf. IAUC 8740), all being Kreutz sungrazers except for C/2006 R3 (Meyer group), which was very small, stellar in appearance, elongated, and of mag about 7.5. K. Battams notes that C/2006 R4 was mostly stellar in appearance with a hint of tail, reaching mag about 3.5. C/2006 S7 shows a hint of tail and was mostly stellar in appearance (mag about 5) in C3 images, while in C2 images it appeared very diffuse and quite faint. C/2006 S8 was slightly elongated and reached mag about 4.5 in C3 images; in C2 images, it was somewhat diffuse with a hint of tail, and it faded quite rapidly. C/2006 S9 appeared stellar with a hint of elongation (mag about 6) in C3 images; in C2 images, it was diffuse with a hint of tail and quite faint. Comet 2006 UT R.A.(2000)Decl. Inst. F MPEC C/2006 R3 Sept. 2.675 10 42.6 + 9 38 C2 HS 2006-U63 C/2006 R4 11.746 10 53.9 + 3 18 C3 TH 2006-U63 C/2006 S7 18.138 11 20.8 + 0 52 C3/2 RM 2006-U63 C/2006 S8 18.488 11 22.4 - 0 03 C3/2 RM 2006-U63 C/2006 S9 18.488 11 27.3 + 0 54 C3/2 RM 2006-U63 (C) Copyright 2006 CBAT 2006 November 11 (8772) Daniel W. E. Green
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