[IAUC] IAUC 9218: C/2011 M1; 2011 MD [25139-2011/04-R1]

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                                                  Circular No. 9218
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
New postal address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
CBATIAU en EPS.HARVARD.EDU           ISSN 0081-0304
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Prepared using the Tamkin Foundation Computer Network


COMET C/2011 M1 (LINEAR)
     An apparently asteroidal object discovered by the LINEAR
survey (discovery observation tabulated below), 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 (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


2011 MD
     A small (H = 28) LINEAR object found on June 22 (cf. MPEC 2011-
M23) will pass only 0.000125 AU from the earth on June 27.71 TT.

                      (C) Copyright 2011 CBAT
2011 June 25                   (9218)            Daniel W. E. Green