P 2010 V1 "-a" "-b" "-c" and 

"-e" "-f" "-g" "-h" "-i" IKEYA-MURAKAMI 

=> 332P IKEYA-MURAKAMI 

COD C10
OBS J.-F. Soulier
MEA J.-F. Soulier
TEL 0.30-m f/3.8 Newtonian reflector + CCD
NET UCAC-4
0332Pa       KC2016 03 13.81623 08 50 02.19 +28 18 28.5          19.1 N      C10
0332Pa       KC2016 03 13.87027 08 50 03.87 +28 17 30.6          18.7 N      C10
0332Pa       KC2016 03 13.91721 08 50 05.34 +28 16 39.4          19.0 N      C10
0332Pb       KC2016 03 13.81623 08 50 09.79 +28 17 47.8          20.4 N      C10
0332Pb       KC2016 03 13.87027 08 50 11.50 +28 16 53.4          20.3 N      C10
0332Pb       KC2016 03 13.91721 08 50 12.93 +28 15 59.9          20.6 N      C10
0332Pc       KC2016 03 13.81623 08 50 11.28 +28 17 42.2          18.9 N      C10
0332Pc       KC2016 03 13.87027 08 50 13.02 +28 16 43.5          18.9 N      C10
0332Pc       KC2016 03 13.91721 08 50 14.41 +28 15 53.1          19.0 N      C10
0332Ph       KC2016 03 13.81623 08 49 16.78 +28 22 02.8          19.6 N      C10
0332Ph       KC2016 03 13.87027 08 49 18.62 +28 21 03.5          19.5 N      C10
----- end -----





Confirmation fragment "-d" but = E  (CBET 4254)


COMET P/2015 Y2 = P/2010 V1 (IKEYA-MURAKAMI)
    Further to CBET 4250, J.-F. Soulier, Maisconcelles, France, reports the
discovery of a fifth fragment of comet P/2015 Y2, here denoted component E,
some 2'.5 to the west-northwest of fragment A on images taken with a 0.3-m
f/3.8 reflector on Feb. 4.0 UT at magnitude 20.1-20.5 (cf. MPEC 2016-C30,
where it was incorrectly identified as component D).  Fragment E was also
observed by R. A. Kowalski via the Mount Lemmon Survey with a 1.5-m reflector
on Feb. 3.2 at mag 19.9-20.9 (MPEC 2016-C30); by P.-J. Dekelver with the 2-m
"Faulkes Telescope North" f/10 reflector on Feb. 1.4 and 4.4 at magnitudes
21.8-21.9 and 21.9-22.2, respectively; with the 1.8-m Pan-STARRS1 telescope
on Haleakala on Feb. 4.4 at magnitude 21.5-21.9; and by others.
    F. Colas, L. Maquet, and F. Pierret, IMCCE, Observatoire de Paris, report
the discovery of a sixth fragment of comet P/2015 Y2 at magnitude 22.0 on
images made on Feb. 5.05-5.11 UT with the 1-m telescope at Pic du Midi
observatory, here denoted component F; other magnitudes for the comet's
fragments are as follows:  A, 19.0; B, 21.2; C, 18.2, E ("D" on MPEC
2016-C30), 20.9.  Colas notes that fragment F is 16" from component E (i.e.,
from "D" of MPEC 2016-C30).  Fragments A, C, E, and F appear condensed and
elongated.  Fragment B is rather more complex, and it seems to be in
complete disintegration, with now two fragments (each of mag about 23) on
each side at 10" distance from the central diffuse fragment, producing a
wide debris trail.
    The discovery of a seventh fragment and an eighth fragment is reported
by F. Kugel, Dauban, France, on images taken with a 0.4-m reflector on Feb.
5.95 UT.  These fragments, respectively designated G and H, both have
brightness around magnitude 21.0, each appears in p.a. 289 deg with respect
to fragment C at distances 15'04" (fragment G) and 20'44" (fragment H).
Other distances (in p.a. 289 deg) and magnitudes of the various fragments
from component C (which was then measured to be mag 17.8) on Feb. 5.95:  B,
21", 21.0; A, 2'25", 18.2; D, 4'50", 20.8.  Regarding Kugel's earlier images
image taken on Jan. 3.2 in poor seeing, fragment A is slightly condensed and
of red mag 19.3-19.5, while fragment B is diffuse and of similar brightness.
On Jan. 5.23, fragment A is well-condensed and slightly brighter, while
fragment B is elongated toward p.a. 290 deg; the image for that date is
posted at http://lesia.obspm.fr/comets/lib/display-obs1.php?Num=15013.
Kugel has also posted additional images and information at website URL
http://www.astrosurf.com/obsdauban/pages/P10V1.html.
    Colas et al. discovered an apparent ninth fragment, of magnitude 22.6
and designated here as fragment J, located 70" to the west-northwest of
fragment E on images from Pic du Midi on Feb. 6.1 UT, which also show more
details in the B/D complex; an image has been posted at the following
website URL:  http://www.picdumidi.eu/T1M/P2010V1-2E.jpg.  Fragments B and D
now form a dust complex with new fragments.  Fragment D is fading to the
north of B, and there are two fragments on each side of B.  All the dust
tails of these fragments are merging to form a wide structure of debris.
Colas gives the magnitudes of other fragments on Feb. 6.1 as follows:
A, 19; B, 21; C, 18.2; E, 21; F, 22.6.

    Z. Sekanina, Jet Propulsion Laboratory, writes that the fifth fragment,
referred to above properly as E, cannot possibly be identified with fragment
D (cf. CBET 4250).  The issue with component E is whether it split off
from the primary nucleus C or from companion A.  At present this remains
uncertain, since the available observations from Feb. 3-4 are about equally
well fitted by either hypothesis.  Very tentatively, the separation appears
to have occurred in late February 2013 if from component C, but in mid-August
2014 if from component A, with a formal (a crude lower limit to actual)
uncertainty of +/- 1 month in either scenario.  Interestingly, the
fragmentation time in the latter case coincides within 4 sigma with the time
of the 2014 observation of the comet from Castelmartini (code 160; MPC 90863);
the component observed then needs to be identified.
    The time of separation of A from C has now been refined as 2012 December
1, with a mean error of +/- 31 days, whereas the differential nongravitational
deceleration was found to equal 5.25 +/- 0.30 units of 10^{-5) the solar
gravitational acceleration; the separation velocity hardly changed at all
from the previously published value (CBET 4250).  A solution forcing the
fragmentation time to coincide with the 2010 outburst now leaves a discernible
systematic trend in the residuals in declination.  If the nucleus fragmented
during the outburst, the products may not have survived until now.
    The assembly of sub-fragments referred to as components B and D, in
the past days detected only intermittently with larger telescopes, appears to
have consisted, at various times, of at least four different clusters, a
conclusion consistent with the description of the Feb. 5 images by Colas et
al.  Attempts to fit their motions relative to component C suggest that they
were released generally between mid-2015 and November 2015, all receding with
the decelerations of more than 10 units; even the most massive among them
were short-lived.
    Available information does not yet allow one to model the fragmentation
history of components F, G, H, and J.
    Preliminary separations and position angles of component E from A and C,
based on the respective fragmentation models (for 0h TT), are as follows:
Feb. 2, 146", 286 deg (A), 287", 289 deg (C); Feb. 12, 150", 285 deg (A),
291", 287 deg (C); Feb. 22, 149", 285 deg (A), 286", 287 deg (C); Mar. 3,
145", 289 deg (A), 274", 288 deg (C).


    
Animation : 2x(10x180s)



Confirmation =>

François Kugel T400 Newton :
http://lesia.obspm.fr/comets/lib/display-obs1.php?Num=15117

and
François Colas T1m Pic du Midi :



M.P.E.C. 2016-C30                                Issued 2016 Feb. 4, 03:30 UT

                     COMET P/2010 V1-D (Ikeya-Murakami)

Observations:
   PK10V01d  C2016 02 03.22423 08 59 15.57 +36 34 05.2          19.9 TqEC030G96
   PK10V01d  C2016 02 03.23041 08 59 15.35 +36 34 03.9                qEC030G96
   PK10V01d  C2016 02 03.23658 08 59 15.01 +36 34 01.6          20.6 TqEC030G96
   PK10V01d  C2016 02 03.24274 08 59 14.72 +36 34 00.9          20.9 TqEC030G96
   PK10V01d KC2016 02 04.02915 08 58 38.14 +36 30 17.5          20.1 TqEC030C10
   PK10V01d KC2016 02 04.04069 08 58 37.62 +36 30 13.7          20.2 TqEC030C10
   PK10V01d KC2016 02 04.05224 08 58 37.03 +36 30 10.6          20.5 TqEC030C10

Observer details:
C10 Maisoncelles.  Observer J.-F. Soulier.  0.30-m f/3.8 Newtonian reflector
   + CCD.
G96 Mt. Lemmon Survey.  Observer R. A. Kowalski.  Measurers E. J. Christensen,
   D. C. Fuls, A. R. Gibbs, A. D. Grauer, J. A. Johnson, R. A. Kowalski,
   S. M. Larson, G. J. Leonard, R. G. Matheny, R. L. Seaman, F. C. Shelly.
   1.5-m reflector + CCD.

Orbital elements:
   P/2010 V1-D (Ikeya-Murakami)
Epoch 2010 Oct. 11.0 TT = JDT 2455480.5
T 2010 Oct. 13.38997 TT                                 MPCW
q   1.5791243            (2000.0)            P               Q
n   0.18141927     Peri.  152.46208     -0.91513648     -0.40299787
a   3.0903934      Node     3.82163     +0.33339683     -0.77168062
e   0.4890216      Incl.    9.37757     +0.22665342     -0.49203835
P   5.43
From 429 observations 2010 Nov. 3-2016 Feb. 4, mean residual 0".7.

   P/2010 V1-D (Ikeya-Murakami)
Epoch 2016 Apr. 2.0 TT = JDT 2457480.5
T 2016 Mar. 17.35367 TT                                 MPCW
q   1.5730663            (2000.0)            P               Q
n   0.18173408     Peri.  152.46547     -0.91489825     -0.40354099
a   3.0868235      Node     3.78386     +0.33386352     -0.77137760
e   0.4903932      Incl.    9.38697     +0.22692805     -0.49206835
P   5.42
From 429 observations 2010 Nov. 3-2016 Feb. 4, mean residual 0".7.

   P/2010 V1-D (Ikeya-Murakami)
Epoch 2021 Aug. 14.0 TT = JDT 2459440.5
T 2021 Aug. 18.51635 TT                                 MPCW
q   1.5772395            (2000.0)            P               Q
n   0.18151251     Peri.  152.35335     -0.91412813     -0.40528250
a   3.0893350      Node     3.78684     +0.33535928     -0.77080033
e   0.4894566      Incl.    9.38002     +0.22782432     -0.49154140
P   5.43
From 429 observations 2010 Nov. 3-2016 Feb. 4, mean residual 0".7.

   P/2010 V1-D (Ikeya-Murakami)
Epoch 2016 Jan. 13.0 TT = JDT 2457400.5
T 2016 Mar. 17.36121 TT                                 MPCW
q   1.5730626            (2000.0)            P               Q
n   0.18176524     Peri.  152.46895     -0.91492841     -0.40347255
a   3.0864707      Node     3.78467     +0.33380530     -0.77140423
e   0.4903361      Incl.    9.38684     +0.22689208     -0.49208273
P   5.42
From 429 observations 2010 Nov. 3-2016 Feb. 4, mean residual 0".7.

Ephemeris:
   P/2010 V1-D (Ikeya-Murakami)
Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase   m1    m2
2016 01 05    09 12 07.6 +36 13 01   0.7984  1.7154   148.5    17.4  20.9
...
2016 01 20    09 08 44.1 +36 55 23   0.7103  1.6649   158.4    12.6  20.5
...
2016 01 28    09 03 50.3 +36 53 18   0.6799  1.6419   160.8    11.4  20.3
...
2016 02 03    08 59 25.3 +36 35 05   0.6647  1.6266   160.2    11.8  20.2
2016 02 04    08 58 39.8 +36 30 29   0.6629  1.6243   159.9    12.0  20.2
2016 02 05    08 57 54.3 +36 25 26   0.6612  1.6219   159.6    12.2  20.2
...
2016 02 11    08 53 31.5 +35 45 11   0.6548  1.6090   156.6    14.1  20.1
...
2016 02 19    08 48 50.6 +34 25 46   0.6561  1.5948   151.1    17.4  20.1
...
2016 03 05    08 46 30.5 +30 51 52   0.6860  1.5775   139.5    24.1  20.2

Gareth V. Williams           (C) Copyright 2016 MPC           M.P.E.C. 2016-C30


           


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