Circular No. 8747
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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(134340) PLUTO, (136199) ERIS, AND (136199) ERIS I (DYSNOMIA)
Following the Aug. 24 resolution by the IAU to the effect that the
solar system contains eight “planets” (Mercury–Neptune), with (1) Ceres,
Pluto (cf.
IAUC
255), and 2003 UB
313
(cf.
IAUC
8577) to be considered
representative “dwarf planets”, the Minor Planet Center included Pluto
and 2003 UB
313
(along with two other new potential dwarf-planet candi-
dates) in the standard catalogue of numbered objects with well-determined
orbits as (134340) and (136199), respectively (see
MPC
57525). Following
near-unanimous acceptance by both the Committee on Small-Body Nomen-
clature and the Working Group on Planetary-System Nomenclature (in
consultation with the discovery team), the IAU Executive Committee has
now approved the names Eris for (136199) and Dysnomia for its satellite
(136199) Eris I [formerly S/2005 (2003 UB
313
) 1; cf.
IAUC
8610].
COMET 178P/HUG-BELL
Comet P/1999 X1 = 2006 O1 (cf.
IAUC
8730) has been given the
permanent number 178P (cf.
MPC
57382).
COMET P/2006 R1 (SIDING SPRING)
Additional astrometry and the following improved orbital elements for
this comet (cf.
IAUC
8744) appear on
MPEC
2006-R47. The orbital period,
P
, is the shortest known for a comet with a retrograde orbit.
T
= 2006 Sept. 3.833 TT
ω
= 249
o
.322
e
= 0.68901
Ω = 218
.
561
¾
2000
.
0
q
= 1.66976 AU
i
= 160
.
021
a
= 5
.
36919 AU
n
o
= 0
.
079221
P
= 12
.
4 years
SUPERNOVA 2006ev IN UGC 11758
Michel Ory, Vicques, Switzerland, reports the discovery of an appar-
ent supernova (red mag
≈
16.6) on CCD images taken on Sept. 12.9 and
13.8 UT with a 0.61-m
f
/3.88 reflector. The new object is located at
α
=
21
h
30
m
59
s
.26
±
0
s
.05,
δ
= +13
o
59
0
21
00
.2
±
0
00
.2 (equinox 2000.0), which is
23
00
east and 11
00
north of the nucleus of UGC 11758. Nothing is visible at
this location on a red Palomar Sky Survey plate from 1953 Aug. 19 or a
red U.K. Schmidt Telescope plate from 1991 Aug. 14.
2006 September 13
c
°
Copyright
2006 CBAT
Daniel W. E. Green