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24 August 2010
IAU Circular No.9163

COMET P/2010 Q1 (SCOTTI)

J. V. Scotti, University of Arizona, reports the recovery of
comet P/2000 Y3 (cf. IAUCs 7552, 7553) as an essentially stellar
object on images obtained on Aug. 19 and 20 with the 0.9-m
Spacewatch reflector at Kitt Peak (first observation tabulated
below).

2010 UT R.A. (2000) Decl. Mag. Observer
Aug. 19.37705 1 57 22.03 +13 10 01.1 20.9 Scotti

The indicated correction to the prediction on MPC 65937 is Delta(T)
= -0.46 day. The astrometry (including accidental observations
obtained by T. H. Bressi on 2009 Sept. 18 with the 1.8-m Spacewatch
reflector), linked orbital elements (epoch 2012 Feb. 3.0 TT, T =
2012 Jan. 20.3218 TT, e = 0.199930, q = 3.918196 AU, Peri. =
92.5913 deg, Node = 354.1592 deg, i = 2.2591 deg, equinox 2000.0, P
= 10.84 years), residuals, and an ephemeris appear on MPEC 2010-Q19.


COMET 103P/HARTLEY

M. Knight, E. Schwieterman, and D. Schleicher, Lowell
Observatory, obtained and analyzed extensive CN narrowband images
of comet 103P on five consecutive nights (2010 Aug. 13-17) using
the Hall 1.1-m telescope at Lowell Observatory. Following the
removal of median radial profiles, an oscillating CN gas feature is
seen centered near position angle 350 deg, consistent with a side-
on cork-screw jet morphology; no dust feature other than the tail
was visible in R-band images. Intervals between 15 pairs of
matching CN images from various rotational cycles, coupled with the
spacing and the outward motion of the feature, imply a nucleus
rotation period of 16.6 +/- 0.5 hr, consistent with the result by
Meech et al. (2009, BAAS 41, 1029). Preliminary modeling suggests
a moderate obliquity of the rotation axis and a mid-latitude source
location.
Schleicher adds that he obtained six sets of narrowband
photometry of comet 103P on Aug. 11 and 12 (when r = 1.48-1.47 AU)
using the Hall 1.1-m telescope, resulting in the following averaged
production rates: log Q(OH) = 27.04; equivalent log Q(water;
vectorial) = 27.09; log Q(NH) = 24.87; log Q(CN) = 24.48; log Q(C_2)
= 24.56; log Q(C_3) = 23.86; log af(rho)(526.0 nm) = 0.93 (cf. IAUC
7342). There is possible evidence of rotational variability, with
values for CN and C_3 lower by 10 percent on Aug. 12 vs. Aug. 11,
while dust was lower by about 20 percent. The implied very-low-
dust-to-gas ratio, based on af(rho) vs. Q(OH), matches Schleicher's
measurements from the 1991 and 1997 apparitions.

2010 August 24 (9163) Daniel W. E. Green

30 August 2010
IAU Circular No.9164

NUMBERING OF PERIODIC COMETS

The following seven comets have been given permanent
numberings: 238P/2010 N2 = 2005 U1 (Read; cf. IAUC 9158);
239P/2010 C2 = 1999 XB_69 (LINEAR; cf. IAUC 9159); 240P/2010 P1 =
2002 X2 (NEAT; cf. IAUC 9159); 241P/2010 P2 = 1999 U3 (LINEAR;
IAUC 9160); 242P/2010 P3 = 1998 U4 (Spahr; cf. IAUC 9161);
243P/2010 P5 = 2003 S2 (NEAT; cf. IAUC 9162); 244P/2010 Q1 =
2000 Y3 (Scotti; cf. IAUC 9163).


COMETS C/2009 X3-X17 (SOHO)

Further to IAUC 9162, additional Kreutz sungrazers have been
found on SOHO website images. C/2009 X3, which was very close to
C/2009 X2 (cf. IAUC 9162), was diffuse with a short tail. C/2009
X4 was stellar in appearance (peak mag about 7-7.5). C/2009 X5 and
C/2009 X8 were very small (mag about 7.5-8). C/2009 X6 (mag about
7) and C/2009 X7 (mag about 7.5-8) were slightly diffuse. C/2009
X9 (mag about 6) was slightly diffuse with a tail. C/2009 X10 (mag
about 7.5) and C/2009 X11 (mag about 8-8.5; barely visible) were
very small. C/2009 X12 was very diffuse (peak mag about 7-7.5).
C/2009 X13 was diffuse (mag about 7). C/2009 X14 was small and
faint (mag about 8). C/2009 X15 and C/2009 X17 were diffuse (peak
mag about 7-7.5). C/2009 X16 was slightly diffuse (mag about 7).

Comet 2009 UT R.A.(2000)Decl. Inst. F MPEC
C/2009 X3 Dec. 1.779 16 29.3 -24 41 C3/2 TS 2010-M16
C/2009 X4 2.496 16 35.3 -23 46 C2 BZ 2010-M16
C/2009 X5 4.038 16 43.6 -24 04 C2 MU 2010-M16
C/2009 X6 4.579 16 46.0 -24 11 C2 JR 2010-M16
C/2009 X7 4.688 16 44.8 -24 04 C2 RK 2010-M16
C/2009 X8 6.104 16 51.2 -24 18 C2 BZ 2010-M17
C/2009 X9 6.929 16 51.3 -26 57 C3/2 AK 2010-M17
C/2009 X10 7.064 16 55.8 -24 26 C2 BZ 2010-M17
C/2009 X11 7.396 16 56.9 -24 27 C2 JR 2010-M17
C/2009 X12 8.596 17 02.1 -25 28 C3/2 MU 2010-M17
C/2009 X13 10.071 17 09.4 -25 25 C3/2 MU 2010-M18
C/2009 X14 11.038 17 14.1 -24 50 C2 JR 2010-M18
C/2009 X15 13.688 17 26.5 -25 04 C2 MK 2010-M18
C/2009 X16 13.888 17 27.5 -26 10 C3/2 MU 2010-M18
C/2009 X17 15.604 17 35.4 -25 08 C2 BZ 2010-M18

2010 August 30 (9164) Daniel W. E. Green