1 Oct 2003
(Source: University of Hawaii)
Note: The discovery of the new Uranus satellite is described in the first new release. The second item is scientific details on the discovery of both new moons is listed in the International Astronomical Union's bulletin.
New Satellite of Uranus S/2001 U2
University of Hawaii
October 1, 2003
Scott S. Sheppard and David Jewitt at the University of Hawaii discovered the satellite on images obtained from the Subaru 8.3m telescope atop Mauna Kea in Hawaii on August 29, 2003. Further observations by the Hawaii team allowed Brian Marsden at the Minor Planet Center to link the object to independent discovery observations obtained in 2001 by a group lead by Matt Holman and JJ Kavelaars. The 2001 observations were not enough to determine if the object was a satellite of Uranus and no reliable orbit was found. It was then lost until discovery in 2003 by the Hawaii team.
The new Uranus satellite S/2001 U2 was announced by the International Astronomical Union at the beginning of October. The new satellite is about 12 kilometers in diameter and has an orbital period of about 8 years. Uranus now has 25 known satellites of which 7 have irregular orbits.
Circular No. 8213
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
S/2001 U 2 AND S/2002 N 4
A new Uranian satellite candidate (R = 24.9-25.1) was observed on 2001 Aug. 13 (Cerro Tololo, Blanco 4-m reflector) and Sept. 21 (Palomar, Hale 5-m refl.) by teams led by M. Holman and B. Gladman (for other participants and affiliations, see IAUC 7980), but further attempts to observe the object proved unsuccessful. On 2003 Sept. 24, B. G. Marsden identified this object, now designated S/2001 U 2, with a satellite candidate (R = 25.0-25.2) observed by S. S. Sheppard, University of Hawaii, on images obtained by D. C. Jewitt and himself on 2003 Aug. 29-30 (Subaru 8.2-m reflector) and Sept. 20 (Gemini 8.2-m reflector), and confirming observations were made by Holman on Sept. 30 (Las Campanas, Clay 6.5-m reflector).
A new Neptunian satellite candidate (R = 24.6-25.2) was observed on 2002 Aug. 14 and 16 (Blanco reflector) and Sept. 3 (Cerro Paranal, 8.2-m UT3 telescope) by teams led by Holman and Gladman (for other participants and affiliations see IAUC 8047) and also later on Sept. 3 (La Palma, 2.5-m Nordic Optical Telescope) by T. Grav. This object was tentatively recovered by Holman on 2003 Aug. 19 (Blanco reflector, R = 24.3) and confirmed by him on Sept. 28-30 (Clay reflector, R = 24.6).
Full astrometry, Marsden's orbital elements (S/2001 U 2, a = 0.14 AU, e = 0.43, i = 167 deg, H = 12.5; S/2002 N 4, a = 0.32 AU, e = 0.60, i = 139 deg, H = 10.4), and ephemerides are on MPEC 2003-S105 and 2003-S107.
(C) Copyright 2003 CBAT
2003 October 1 (8213) Daniel W. E. Green