The Position of Pluto Relative to its Ephemeris

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

In order to predict the occultations of the stars P126 and P131.1 by Pluto on 2002 July 20 (UT) and August 21 (UT), respectively (see J.L. Elliot et al., 2002, BAAS 34, 877; Buie et al., 2002, BAAS 34, 877; Sicardy, et al., 2002, BAAS 34, 877), astrometric data sets were acquired on several telescopes. The data analyzed for the occultation predictions spanned more than three months (2002 May - 2002 August) and included 189 strip scans from the Lowell Astrograph, 22 frames from the USNO 1.55m, and 61 frames from the Lowell 0.6m at CTIO. The final prediction for closest approach distance appears to be within 100 km (about 0.005") of the observed closest approach for the P126 occultation, and within 200 km (about 0.01") for the P131.1 occultation (note that the angular half light radius of Pluto is about 0.06"; see Clancy et al., 2002, BAAS 34, 873; final predictions are at http://occult.mit.edu/research/occultations/Candidates/Predictions/ P126.html and http://occult.mit.edu/research/occultations/Candidates/Predictions/ P131.1.html). Pluto's position in these frames was determined relative to a UCAC astrometric reference network (Zacharias et al., 2000, AJ 120, 2131), with a dual-source model fit to the blended Pluto-Charon image. The Pluto-Charon offset was fixed with JPL Horizon's Ephemeris (PLU006 and DE-0406, LE-0406), and the Pluto-Charon light ratio was fixed at recent values (updated from Buie et al., 1997, Icarus 125, 233). The residuals of Pluto's measured position from its ephemeris were then fit with a sinusoid of fixed period (Charon's orbital period), while phase, offset, and amplitude were left as free parameters. The fitted phase and amplitude are mutually consistent for all data sets, and the relative amplitude of the RA and Dec sinusoids agree with the relative amplitude of Charon's orbital motion. This implies either an incorrect Charon to Pluto mass ratio (0.12 was used to calculate the ephemeris), or that we used incorrect Pluto-Charon light ratios in this reduction. This work was funded in part by NASA grant NAG5-10444 and NSF grant AST-007 3447.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The Position of Pluto Relative to its Ephemeris does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Position of Pluto Relative to its Ephemeris, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Position of Pluto Relative to its Ephemeris will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1890413

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.