1. Pluto Occultation 20/21 August 2002

2. Occultation Sequence Pluto Charon P131.1 5:33 UT 6:26 UT7:03 UT 7:31 UT

3. 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.

4. Occultation 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. Pluto + Star Pluto only

6. Time (seconds after 8/21 06:40:00 UT) Normalized Flux 0.8 1.0 0.6 0.4 0.0 0.2 450500600650550800700 750 UH 2.2-m/Williams CCD Light Curve

8. 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

9. 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 Technical Details

10. Zoom in of UH 2.2-m/Williams CCD Light Curve

11. Spikes, ingress and egress (flipped)

12. Haleakala data, I-band AEOS Telescope/Boeing LTS

13. Comparison of Light Curves Distance from Shadow Center (in units of half-light radius) Normalized Stellar Flux 0.0 0.6 0.4 0.2 1.0 0.8 0.0–0.5–1.01.51.00.5–1.5

14. Changes in Pluto’s Atmospheric Pressure Emersion (2002) Emersion (1988) 2.06.08.04.0 1275 1255 1235 1215 Pressure (  bar) Radius (km)

15. 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," Nature 424, 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.