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Discovery : IAUC 9218 : comet C/2011 M1 (LINEAR)

An apparently asteroidal object discovered by the LINEAR survey , and posted on the Minor Planet Center's 'NEOCP' webpage, has been reported elsewhere to show cometary appearance by numerous CCD astrometrists. G. Hug (Scranton, KS, U.S.A.; 0.56-m reflector; June 23.4 UT) reports a condensed nuclear condensation with a rich coma extending 20"-25" and no discernible tail. G. Sostero and E. Guido, remotely using a 0.35-m reflector at the Tzec Maun Observatory (TMO) near Mayhill, NM, U.S.A., on June 23.4, write that stacked, unfiltered exposures in moonlight show a coma nearly 30" in diameter (total mag 16.5) with a weak central condensation and a possible faint tail nearly 40" long in p.a. 240 deg. P. Birtwhistle (Great Shefford, Berkshire, England; 0.40-m reflector; June 24.1) notes a poorly condensed coma of diameter 7" with a faint outer coma of diameter 15" and a faint, thin, straight tail at least 48" long in p.a. 252 deg. H. Sato (Tokyo, Japan; remotely using a 0.51-m reflector at the RAS Observatory, Mayhill) finds a very diffuse coma of size 2' and total red mag 14.5 on June 24.35; his images from June 24.4 show a 140" coma of total mag 14.4. E. Bryssinck (Kruibeke, Belgium) stacked, unfiltered images obtained remotely with a TMO 0.35-m reflector) notes a very faint diffuse coma of size about 74" on June 24.4 and 88" on June 25.4, with a faint central condensation of size 15"-16" of mag 18.1. R. Ligustri (Udine, Italy; remotely with a 0.25-m reflector at the RAS Observatory, Mayhill; June 24.4) finds a faint coma of size about 30". D. Chestnov writes that unfiltered CCD exposures taken by A. Novichonok with a TMO 0.36-m reflector on June 25.39 show a diffuse 3'.2 coma of total mag about 13.5. 2011 UT R.A. (2000) Decl. Mag. Observer June 22.37866 0 27 01.17 +40 19 03.4 18.6 LINEAR The available astrometry, the following parabolic orbital elements by G. V. Williams, and an ephemeris appear on MPEC 2011-M37. T = 2011 Sept. 7.597 TT Peri. = 119.040 Node = 324.629 2000.0 q = 0.90472 AU Incl. = 69.975

Comet C/2011 M1 (LINEAR)

Photometric data obtained from FOCAS-II software:

                                   10x10  20x20  30x30  40x40  50x50  60x60   SNR   SB   COD

OBJECT        DATE       TIME        +/-    +/-    +/-    +/-    +/-    +/-     N  FWHM  CAT

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COMET         UTC                   DELTA    R    APER    Mag   AfRho   +/-   Log   Obs

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