C3132 Observed by 4 MITWilliams teams on 5 telescopes Pico dos Dias Brazil clouded out Jay Pasachoff and Steven Souza Cerro Armazones Chile Bryce Babcock and Joseph Gangestad ID: 716811
Download Presentation The PPT/PDF document "Occultation by Charon 2005" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Occultation by Charon
2005C313.2
Observed by 4 MIT–Williams teams on 5 telescopes: Pico dos Dias (Brazil) – clouded out (Jay Pasachoff and Steven Souza) Cerro Armazones (Chile) (Bryce Babcock and Joseph Gangestad) Las Campanas (Chile) Cerro Pachón (Chile)
Movie of C313.2 from Las
Campanas
- http://occult.mit.edu/research/C313OccMovie.phpSlide2Slide3
Cerro
Armazones, Chile
(L to R) M. J. Person, B. A. Babcock, & J. W. Gangestad
Pico dos Dias, Brazil
S. P. Souza (L), J. M.
Pasachoff
(R) Slide4
Where we were …
… and the parts of Charon we sawSlide5
Cerro Armazones Light Curve
Duration: 37 sec
Mid-time: 03:36:36.5 UTSharp drop No atmosphere detectedSlide6
Team Light Curves
Clay Telescope (6.5 m),
Las Campanas
Gemini South (8 m)
Cerro Pachón
Cerro Armazones (0;.84 m),
Antofagasta, Chile
Du Pont Telescope (2.5 m),
Las Campanas
0.85-m
6.5-m
2.5-m
8-mSlide7
Upper Limits on Charon’s Atmosphere
Gas Molecular Weight
(amu) Number density (1013 cm-3)CH4 16.04 2.0H2O 18.02 3.4Ne 20.18 11.9N2 28.01 2.3
Ar
39.95 2.0
Clay Telescope data
Gulbis
, A.A.S., Elliot, J.L., Person, M.J., Adams, E.R., Babcock, B.A., Emilio, M.,
Gangestad
, J.W., Kern, S.D., Kramer, E.A.,
Osip
, D.J.,
Pasachoff
J.M., Souza, S.P.,
Tuvikene
, T. “
Charon’s
radius and atmospheric constraints from stellar occultation observations”
Nature
, in press
Seconds after reference timeSlide8
Radius and Composition Constraints
Radius: 606 ± 8 km
Density: 1.72 ± 0.15 g/cm3Rock/Ice: 0.63 ± 0.05
This rock/ice fraction is consistent with a collisional formation scenario.
http://ncsdweb.ncsd.k12.wy.us/planetarium/ART/moonimpact.jpg