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IAUC 7610: S/2000 (1998 WW_31) 1; V382 Vel

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                                                  Circular No. 7610
Central Bureau for Astronomical Telegrams
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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S/2000 (1998 WW_31) 1
     C. Veillet, Canada-France-Hawaii Telescope (CFHT), reports:
"Recovery images of the transneptunian object (TNO) 1998 WW_31
(see MPEC 2001-G29) taken by C. Veillet, A. Doressoundiram, and J.
Shapiro with the 3.6-m CFHT show that two objects were within <
1".3 and moving together over the two nights of observations (2000
Dec. 22 and 23 UT) without any detectable relative motion.  CFHT
public archive observations of the same field taken nearly a year
previously by J. J. Kavelaars and A. Morbidelli show 1998 WW_31 as
double or elongated on four images, with the two components at a
different distance and position angle than on the discovery images.
A very preliminary reduction shows the brighter component to be 0.4
mag brighter than the secondary in R on 2000 Dec. 22, with the
secondary being 1".2 from the primary in p.a. 45 deg (with seeing
0".7-1".1).  The archival images taken on 2000 Jan. 7.3 show the
secondary to be 0".8 from the primary in p.a. 25 deg.  Images taken
on 2000 Jan. 6 show the same elongation, but the pair is embedded
in a bright star halo, making any measurement difficult.  The
maximum distance between the two components is thus at least 40 000
km.  This indicates that 1998 WW_31 is the second TNO to have a
satellite (after Pluto).  The analysis of other images from the
CFHT, from Kitt Peak (1998 Nov. 18, 1999 Jan. 14, 2000 Nov. 23),
and from the Nordic Optical Telescope (1998 Dec. 18) may allow a
full orbit determination, leading to physical parameters of the
pair.  Images and details on the data are available at

     M. Bos, Mount Molehill Observatory, Auckland; A. Retter, Keele
University; and J. McCormick and F. Velthuis, Farm Cove Observatory,
Auckland, report:  "Unfiltered CCD photometry of N Vel 1999 on
twelve nights during Jan.-Mar. reveals the presence of a
periodicity of 0.14615(1) day in the light curve of this classical
nova together with its first harmonic.  The semiamplitude of the
variation is 0.02 mag."
     Visual magnitude estimates by A. Pearce, Nedlands, W.
Australia:  2000 May 2.59 UT, 10.3; Sept. 23.866, 11.6;
Dec. 2.767, 11.8; 2001 Feb. 26.788, 12.3; Mar. 5.788, 12.4.

                      (C) Copyright 2001 CBAT
2001 April 16                  (7610)            Daniel W. E. Green

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