Source RA J2000 Dec dra ddec errx erry ------------ -------------- ------------- ----- ------- ---- ---- UCAC2 17:41:12.0743 -15:41:34.574 0 0 56 70 2MASS 17:41:12.0800 -15:41:34.500 82 74 60 60 UCAC2-2006 17:41:12.0768 -15:41:34.479 36 95 10 12 MITstrip_1.4 17:41:12.0791 -15:41:34.436 69 138 11 9 Bruno 17:41:12.0769 -15:41:34.485 37 89 0 0 Mimir 17:41:12.0770 -15:41:34.490 38 84 26 36 KPNO 17:41:12.0790 -15:41:34.530 67 44 8 32 ------------------------------------------------------------------- dra and ddec are the offsets from the reference position in mas. errx and erry are the quoted errors in position (and therefore in dra, ddec) in mas. UCAC2 errors include propogated proper motion error. SOURCES UCAC2: the position from the UCAC2 catalog, our reference position. 2MASS: the position from the 2MASS catalog. UCAC2-2006: the position remeasured with the UCAC2 telescope in 2006, provided by Norbert Zacharias MITstrip_1.4: the star position from prediction 1.4 of the MIT group. Bruno: astrometry provided by Bruno Sicardy on May 10, 2006. Mimir : our astrometry with the Mimir IR camera at Lowell, taken by Leslie Young and Marc Buie (Feb) and Marc Buie alone (Apr, May), and analyzed by Leslie Young KPNO : our astrometry from 5 nights in April at Kitt Peak, taken by Peter Tamblyn and analyzed by Leslie YoungThe UCAC2-2006, Mimir, and Bruno's astrometry are all consistent. UCAC2-2006 is East and North of the reference star. If we take UCAC2-2006 as the actual star position, this would move the shadow West by 36 mas and south by 95 mas relative to reference. Combining these, our best estimate is that Pluto is 25 mas East and 44 mas North of the reference (DE413/Plu013) ephemeris.
dra dec errx erry (Pluto - Pluto_ref)_2006jun12 - (star - star_ref) -10 -51 1 1 star - star_ref 36 95 10 12 --------------------- (Pluto - Pluto_ref)_2006jun12 26 44 10 12This could be an adjustment in either the barycenter position or the location of Pluto around the barycenter. For now we assume that the change in Pluto's position is due entirely to an adjustment in the barycenter ephemeris. The uncertainty in the motion of Pluto aroud the barycenter is dominated by uncertainty in the Pluto-Charon mass ratio. The combined uncertainty in the ephemeris adjustment applied to future events is roughly 14 mas.
dra dec errx erry (Pluto - Pluto_ref)_2006jun12 26 44 10 12 (Pluto - Pluto_ref)_2006jun12 - (Pl - Pl_ref)_2007 0 0 8 8 --------------------- (Pluto - Pluto_ref)_2007 26 44 14 14
Work in progress from our group Predictions, discussion and ongoing work by Marc Buie .
2006 May 19 Posted mail text file of Pluto position sent by Norbert Zacharias, measured with the UCAC2 telescope. 2006 Apr 25 New astrometric network using the UCAC2 telescope
From: Norbert ZachariasLeslie formatted this three ways: mpos.pl04s (raw file from Norbert), pl04s.cat (RA, DEC, mag e.g. Input format for Buie's astrometry routines),and pl04s.asterr (file.line, JD, RA, DEC, mag, RAerr_mas, DECerr_mas)To: layoung@boulder.swri.edu Subject: new star catalog from astrograph data Date: Tue, 25 Apr 2006 17:44:56 -0400 060425 Hi Leslie, please find attached a mean position file covering the first part of Pluto's path this year, which should include the June 12 event. The format is as before. The file is sorted by RA and contains 86460 lines (stars). The data does not include the earlier catalog you obtained. We will compile a final catalog containing all the data later this year. Please let me know if you see any problem. Norbert