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IAUC 8980: S/2008 (216) 1, S/2008 (216) 2; P/2008 R1; 205P

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IAUC number

                                                  Circular No. 8980
Central Bureau for Astronomical Telegrams
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
URL http://www.cfa.harvard.edu/iau/cbat.html  ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)

S/2008 (216) 1 AND S/2008 (216) 2
     F. Marchis, Carl Sagan Center at the SETI Institute and
University of California at Berkeley; and his collaborators, P.
Descamps and J. Berthier, Institut de Mecanique Celeste et de
Calcul des Ephemerides, Observatoire de Paris; and J. P. Emery,
University of Tennessee at Knoxville, report on observations of
(216) Kleopatra, a large M-type main-belt asteroid, recorded with
the 10-m Keck II telescope and its adaptive-optics (AO) system
between Sept. 19.27 and 19.50 UT, when the target was at r = 1.237
AU with a phase angle of 7.5 deg.  The direct images recorded with
the NIRC2 camera reach an angular resolution up to 0".032
(corresponding to a spatial resolution of 29 km) with the J_cont
filter (central wavelength at 1.21 microns), permitting
confirmation that the primary has the "dog-bone" shape revealed by
Ostro et al. (2000, Science 288, 836).  The new AO data show
additionally the presence of a about 5-km-diameter companion at
0".72 (projected distance of 650 km) in p.a. 322 deg, detected in
every image recorded over the 5.5-hr baseline.  Careful analysis of
the last set of data indicates the presence of a second satellite,
smaller (about 3 km) and located closer to the primary at an
apparent distance of 380 km (0".42) in p.a. 333 deg.  With (87)
Sylvia (cf. IAUC 8582) and (45) Eugenia (cf. IAUC 8817), this is
the third multiple system with two small-km-sized satellites to be
discovered in the main asteroid belt.

     Improved, elliptical orbital elements for this comet (cf. IAUC
8969) from MPEC 2008-S46:

     T = 2008 July 25.200 TT          Peri. = 256.436
     e = 0.34203                      Node  =  52.018   2000.0
     q = 1.79261 AU                   Incl. =  15.899
       a =  2.72444 AU     n = 0.219174     P =   4.50 years

     MPEC 2008-S47 contains astrometry and ephemerides for
components A, B, and C (cf. IAUC 8980), and also revised orbital
elements (with nongravitational parameters) satisfying the primary
component during 1896-2008.  Visual total-magnitude estimates for
component A:  Sept. 11.07 UT, 12.7 (J. J. Gonzalez, Palencia, Spain,
20-cm reflector); 16.96, 12.9 (M. Goiato, Aracatuba, Brazil, 22-cm
reflector); 19.83, 12.2 (Gonzalez, Leon).

                      (C) Copyright 2008 CBAT
2008 September 24              (8980)            Daniel W. E. Green

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