Pluto

A New Horizons image showing Sputnik Planum and adjacent mountains on Pluto from the 2015 flyby by the NASA spacecraft.

Long thought to be the 9th planet, then reclassified in 2006 as a dwarf planet, Pluto is now also honored as the first plutoid. It has an atmosphere and five known moons: Charon, Styx, Nix, Kerberos, and Hydra. Since it passed perihelion in 1989, it has been receding from the sun and it was interesting that the atmosphere was still warming when we started observing it in 2002. We are now participating in monitoring the atmosphere’s temperature and density, and even had an occultation just before the flyby that showed conditions there when NASA’s New Horizons spacecraft arrived there in 2015.  We continue to work with the MIT group headed by Mike Person and Amanda Bosh, with collaborator Amanda Sickafoose at the South African Astronomical Observatory at MIT, on occultation studies.

• New Horizons mission, NASA link
• New Horizons mission, JHU/APL link
• See Charon orbiting Pluto (April 12-18, 2015)

Refereed Papers

• The recent expansion of Pluto’s atmosphere (Elliot et al., Nature 424, 165-168, 10 July 2003)
• J. L. Elliot, M. J. Person, and S. Qu, 2003, Analysis of Stellar Occultation Data. II. Inversion, with Application to Pluto and Triton,* Astronomical Journal 126, 1041, doi: 10.1086/375546
• The Structure of Pluto’s Atmosphere from the 2002 August 21 Stellar Occultation (Pasachoff et al., Astronomical Journal 129, 1718-1723, March 2005)
• Changes in Pluto’s Atmosphere: 1988-2006 (Elliot et al., Astronomical Journal 134, 1-13, July 2007)
• Waves in Pluto’s Upper Atmosphere (Person et al., Astronomical Journal 136, 1510-1518, October 2008)
• The 2011 June 23 Stellar Occultation by Pluto: Airborne and Ground Observations (Person et al., The Astronomical Journal 146(4), 83, 2013)
• Gulbis, A. A. S., J. P. Emery, M. J. Person, A. S. Bosh, C. A. Zuluaga, J. M. Pasachoff, and B. A. Babcock, 2013, “Observations of a 2011 stellar occultation by Charon and graze by Pluto,” conference on The Pluto System on the Eve of Exploration by New Horizons: Perspectives and Predictions”
• Observations of a successive stellar occultation by Charon and graze by Pluto in 2011: Multiwavelength SpeX and MORIS data from the IRTF (Gulbis, Emery, Person, Bosh, Zuluaga, Pasachoff, and Babcock, 2015)
• The State of Pluto’s Atmosphere in 2012-2013 (Bosh, Person, Levine, Zuluaga, Zangari, Gulbis, Schaefer, Dunham, Babcock, Davis ’14, Pasachoff, et al., 2015)
• J. L. Elliot, M. J. Person, and S. Qu, 2003, Analysis of Stellar Occultation Data. II. Inversion, with Application to Pluto and Triton,* Astronomical Journal 126, 1041, doi: 10.1086/375546

Abstracts

• Changes in Pluto’s Atmosphere Revealed by the P126A Occultation (Buie et al., B.A.A.S. 34, No. 3, 877, 9 October 2002)
• Pluto Occultation of P131.1 in 2002 August: Overview of Observations and Infrared Results (Elliot et al., B.A.A.S. 34, No. 4, 1211, 7 January 2003)
• High-Time-Resolution White-Light Observations of Pluto’s Occultation of P131.1 in 2002 August (Pasachoff et al., B.A.A.S. 34, No. 4, 1211, 7 January 2003)
• Examination of Pluto’s Figure with the P131.1 Stellar Occultation (Person et al., B.A.A.S. 34, No. 4, 1211-12, 7 January 2003)
• Pluto’s Atmospheric Figure from the P131.1 Stellar Occultation (Person et al., B.A.A.S. 35, No. 4, 957, September 2003)
• Fascinating Pluto (Pasachoff et al., Physics Today Vol. 57, Issue 9, pp. 18, September 2004)
• A Search for Rings, Moons, or Debris in the Pluto System during the 2006 July 12 Occultation (Pasachoff et al., B.A.A.S. 38, No. 3, 523, September 2006)
• Pluto’s atmospheric structure: results from the 2006 June 12 stellar occultation (Gulbis et al., B.A.A.S. 38, No. 3, 541, September 2006)
• The Size of Pluto’s Atmosphere As Revealed by the 2006 June 12 Occultation (Elliot et al., B.A.A.S. 38, No. 3, 541, September 2006)
• Stellar Occultation by Pluto of P445.3 (2UCAC 25823784) on 2007 March 18 (UT) (Person et al., IAU Circular 8825 as “(31340) Pluto”)
• Observational Results from the 2007 March 18 Pluto Stellar Occultation (Pasachoff et al., B.A.A.S. 39, No. 3, 541, October 2007)
• High Altitude Structure in Pluto’s Atmosphere from the 2007 March 18 Stellar Occultation (Person et al., B.A.A.S. 39, No. 3, 519, October 2007)
• Probing small bodies in the outer solar system with stellar occultations (Person et al., European Planetary Science Conference 2008, Münster)
• Pluto Stellar Occultation on 2008 Aug 25 (Buie et al., B.A.A.S. 41, No. 1, 562-563, January 2009)
• The 3/4 July 2010 Pluto Stellar-Occultation Observations (Pasachoff et al., 2010)
• Pluto and Beyond: Stellar-Occultation Web Pages for Education and Observation Planning (Pasachoff et al., 2010)
• Pluto’s Atmosphere from the July 2010 Stellar Occultation (Person et al., 2010)
• Stellar-Occultation Web Pages for Education and Planning (Pasachoff et al., 2010)
• The 22 May 2011 Pluto Occultation – Observed (Pasachoff et al., 2011)
• The Double-Double Pluto-Charon and Pluto-Hydra Predicted Stellar Occultations of June 2011 (Pasachoff et al., 2011)
  
• The measured Pluto-Charon offset from the stellar occultations of 23 June 2011 (Zuluaga et al., 2011)
• Probing Pluto’s Upper Atmosphere: a 2011 Occultation Graze in Visible Images and Infrared Spectra (Gulbis et al., 2012)
• Recent KBO (Pluto/Charon and beyond, including Quaoar) Occultation Observations by the Williams College Team as part of the Williams-MIT Collaboration (Pasachoff et al., 2013)
• The State of Pluto’s Atmosphere in 2012-13 (Bosh et al., 2013)

Popular Treatments

• Pasachoff, Jay M., and James L. Elliot, 2004, “Fascinating Pluto,” The Physics Teacher 57 (9), letter, September, 18
• Click Here for PDF of The Physics Teacher article
• Pasachoff, Jay M., 2010, podcast: about the total eclipse of July 11 and the July 3 Pluto occultation
• Pasachoff, planethunters blog 1 (2011)
• Pasachoff, NASA Planetary Astronomy, Science Mission Directorate, Nugget, “Pluto Twinkles Starlight” (2014) Pasachoff, planethunters blog 2 (2015)
• Planet Hunters| A Zooniverse Project Blog

Miscellaneous Information

• 1988 Pluto Occultation Lightcurve PowerPoint
• August 2002 Pluto Occultation PowerPoint
• 2002 Pluto Occultation Press Release
• June 2006 Pluto Occultation PowerPoint
• March 2007 Pluto Occultation PowerPoint
• June 2008 Pluto Occultation Path PowerPoint
• August 2008 Pluto Occultation PowerPoint
• July 2010 Pluto Occultation PowerPoint
• July 2010 Pluto Occultation Path
• July 2010 Pluto Occultation Prediction by MIT Group
• May 22, 2011 Pluto Occultation Prediction by MIT Group
• June 23, 2011 Pluto Occultation Prediction by MIT Group
• June 27, 2011 Pluto Occultation Prediction by MIT Group
• July 20, 2011 NASA’s Hubble Discovers Another Moon Around Pluto
• New Horizons mission, NASA link
• New Horizons mission, JHU/APL link
• Wikipedia, “Pluto”
• Gallery of Images
• Some Pluto photos
• Sky and Telescope: Down-Under Observers Track Pluto Cover-Up
• Planet Hunters: Blocking Starlight Much Closer to Home 2: This Year’s Pluto Occultation
• Planet Hunters: Update from Jay Pasachoff’s Pluto Occultation program
• New Horizons’ Top 10 Pluto Pics