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Pluto Occultation. 20/21 August 2002. Occultation Sequence. 7:31 UT. 5:33 UT. 6:26 UT. 7:03 UT. Pluto. Charon. P131 .1. Occultations by Pluto. 2002 P131.1. Pluto + Star. Pluto only. Williams’s light curve from August 2002, taken at University of Hawaii 2.2-m telescope.
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Pluto Occultation 20/21 August 2002
Occultation Sequence 7:31 UT 5:33 UT 6:26 UT 7:03 UT Pluto Charon P131.1
Occultations by Pluto 2002 P131.1 Pluto + Star Pluto only Williams’s light curve from August 2002, taken at University of Hawaii 2.2-m telescope Pasachoff, Jay M., Steven P. Souza, Bryce A. Babcock, David R. Ticehurst (Williams College); James L. Elliot, M. J. Person, and Kelly B. Clancy (MIT); Lewis C. Roberts, Jr., and Doyle T. Hall (Boeing Co., Maui); and David J. Tholen (U. Hawaii) 2005, "The Structure of Pluto's Atmosphere from the 2002 August 21 Stellar Occultation," Astron. J., 129, 1718-1723.
Occultation by Pluto 2002 P131.1 Pluto + Star Pluto + Star Pluto only Pluto only Williams’s light curve from August 2002, taken at University of Hawaii 2.2-m telescope Pasachoff, Jay M., Steven P. Souza, Bryce A. Babcock, David R. Ticehurst (Williams College); James L. Elliot, M. J. Person, and Kelly B. Clancy (MIT); Lewis C. Roberts, Jr., and Doyle T. Hall (Boeing Co., Maui); and David J. Tholen (U. Hawaii) 2005, "The Structure of Pluto's Atmosphere from the 2002 August 21 Stellar Occultation," Astron. J., 129, 1718-1723.
UH 2.2-m/Williams CCD Light Curve 1.0 0.8 0.6 Normalized Flux 0.4 0.2 0.0 450 500 550 600 650 700 800 750 Time (seconds after 8/21 06:40:00 UT)
Half-light immersion time: 2002 08 21: 06 47 59.3038 UT Half-light emersion time: 2002 08 21: 06 53 08.4001 UT Duration: 5.15 minutes
Technical Details Observations: Mauna Kea, 20 August 2002 Telescope: University of Hawaii 2.2 m f/10.14 CCD: Princeton Instruments (Roper Scientific) TE/CCD-576EFT frame-transfer CCD Frame Capture Rate = 2 Hz Resolution: 0.2 arc sec pixels unbinned for astrometric images binned 5x5 for 20-min occultation run Seeing: 0.4 arc sec Support: Research Corporation
Comparison of Light Curves 1.0 0.8 0.6 Normalized Stellar Flux 0.4 0.2 0.0 –1.5 –1.0 –0.5 0.0 0.5 1.0 1.5 Distance from Shadow Center (in units of half-light radius)
Changes in Pluto’s Atmospheric Pressure 1275 1255 Radius (km) 1235 1215 Emersion (2002) Emersion (1988) 2.0 4.0 6.0 8.0 Pressure (mbar)
Papers published "High-Time-Resolution White-Light Observations of Pluto's Occultation of P131.1 in 2002 August” Elliot et al. "The recent expansion of Pluto's atmosphere," Nature424, 165-168, July 10, 2003. Pasachoff et al. Astronomical Journal paper on our data. Person et al. Meeting paper on the shape of Pluto’s atmosphere.