Transit Timing Variation (TTV) of Exoplanets
& Other Exoplanet Science
Howard M. Relles, last updated (1x) 22 May 2015
This exoplanet science website discloses transit timing variations (TTVs) for many of the recently designated Kepler exoplanet candidates. In addition to being of potential interest to the exoplanet research community, it is hoped that these will encourage additional analyses and expanded interpretations.
Other areas of exoplanet science will also be discussed especially if they derive from NASA’s Kepler space telescope mission or its creative extended K2 mission.
TTV: When two or more planets orbit the same star, their orbital periods can be increased or deceased (by minutes to hours) as a result of their mutual gravitational attraction as they pass each other. For transiting exoplanet systems where planetary radii are known, the corresponding observed variations in transit times provides to one of the most powerful techniques for obtaining planetary masses and, hence, densities. To date, only a handful of exoplanets’ properties have been reported via this approach (see refs. 1) because of a variety of astrophysical uncertainties as well as the mathematical complexities involved in the TTV-to-properties conversions. It is hoped that this website will foster interest by those professionals with the required skills to develop computer codes for automating the TTV-to-properties conversions…and then similarly to make such code(s) freely available. Such would be a powerful tool for accelerating our understanding of planetary systems as well as our ultimate push toward finding biology everywhere in the Universe.
All transit times (through Kepler’s Q16 and/or Q17) along with numerous other properties have been calculated with the EXOFAST code of Eastman, Gaudi, and Agol (ref. 7) using light-curve data from publicly available NASA Exoplanet Archives (“NEA”) tables (ref. 8). (A complete description of EXOFAST output parameters can be found at: http://astroutils.astronomy.ohio-state.edu/exofast/outputs.html.) In general, systems with relatively large TTVs will be displayed on this site; the site will continue to expand as additional TTVs are uncovered. Please check it frequently.
If you make use of the research presented, please acknowledge with the reference:
Relles, H. M., http://exoplanet-science.com, 2013-2015.
Email Contact: rellesh [at] yahoo [dot] com
It is a pleasure to acknowledge the support and encouragement of Eric Agol, Rachel Akeson, Jason Barnes, Rory Barnes, Jason Eastman, Dan Fabrycky, Eric Ford, Bruce Gary, Nader Haghighipour, Joe Harrington, René Heller, Heather Knutson, Greg Laughlin, Abel Méndez, and Carolina vonEssen. Thanks also to Joe Rocco for his continued interest in exoplanets.
“Chance favors the prepared mind” — Louis Pasteur