The Kepler Project fosters self-governing working groups of community scientists to advance and recommend upon aspects of primary mission science. Working groups also collaborate on science projects that are complementary to the primary science goals. The following is a list of the groups that are currently active, with links to a short description of the group's area of interest as well as a contact for those interested in participating or obtaining more information:
Individuals interested in forming new Working Groups related to the detection, confirmation, and characterization of exoplanets and/or the determination of planet occurrence rates can contact the Kepler Mission Scientist (Natalie Batalha) for information. Working group members are kept abreast of project activities via team telecons (~ 6 times per year). They participate in the evaluation of short-cadence targets each quarter for analyses related to the primary mission goals. Working group members are also invited to attend bi-annual meetings (held at least once per year in Mountain View, California).
Active working groups related to primary mission science have representation on the Kepler Exoplanet Council (KEC). The council provides recommendations to the Kepler project and acts as a liaison to the broader scientific community with regards to the primary exoplanet goals of the mission. The KEC charter and membership can be found at the link above.
1. High-Level Descriptions
Threshold Crossing Event Review Team (TCERT)
POC: Michael Haas, NASA Ames Research Center
The Threshold-Crossing-Event Review Team (TCERT) is responsible for reviewing and dispositioning the Threshold Crossing Events (TCEs) identified by the Kepler Pipeline. A TCE is a statistically significant transit signal detected by Kepler's analysis pipeline. During the initial review process, TCEs that indicate a planetary-size companion are declared Kepler Objects of Interest (KOIs) and subjected to additional tests and more rigorous scrutiny. Once this in-depth analysis and evaluation is complete, each KOI will be dispositioned as a planetary candidate or false positive. These results will be delivered on a regular basis to NExScI for public release through their Exoplanet Archive. Besides participating in the TCE vetting process, the group helps to review pipeline products, procedures, and documentation with the goal of improving them for increased product reliability and operational efficiency.
Follow-up Observing Program (FOP)
POC: David Ciardi, NASA Exoplanet Science Institute
The scientific goals of the Kepler Extended Mission Follow-up Observation Program (XMFOP) are to confirm and validate the planetary nature of the Kepler Objects of Interest (KOIs) via the determination of stellar parameters, radial velocity curves, and stellar blends. Besides yielding exoplanet confirmations and characterizations, the work results in more accurate properties of the KOI host stars and, consequently, the planet candidates they harbor. The work also yields a better understanding of the overall reliability of the KOI catalog. The XMFOP performs the following duties in support of Kepler's scientific goals:
- Spectroscopic observations for the purpose of determining stellar properties.
- Spectroscopic observations for the purpose of identifying stellar companions and/or placing limits on the presence of such companions.
- High-precision radial velocity for a limited sample of relatively small exoplanet candidates to determine their masses and other orbital properties.
- High spatial resolution imaging for the purpose of detecting line-of-sight and/or physically associated stars in the photometric aperture and/or placing constraints on the presence of such blends.
- Other supporting observations as opportunities arise (e.g. Spitzer, HST, etc).
XMFOP members participate in weekly telecons to strategize and discuss progress and select KOIs for follow-up observations based on the scientific priorities of the mission. Participation the XMFOP stimulates collaboration and provides for efficient observations, thereby reducing duplicative efforts, and provides opportunities for observers not funded directly by the mission to contribute directly to core mission objectives.
False Positive Working Group (FP)
POC: Steve Bryson, NASA Ames Research Center
There are instrumental and astrophysical signals that mimic planetary transits in the Kepler flux time series. The Kepler False Positive Working Group is oriented towards identifying such astrophysical and instrumental false positives (FP) among the Kepler Objects of Interest (KOIs). The mandate of the FP working group is to:
- Identify/confirm false positive KOIs via analysis of Kepler data.
- Track and incorporate false positive identifications from other observations from both the Kepler community follow up program and other sources.
- Identify sources of FP signals and recommend appropriate action (such as addition to the eclipsing binary catalog).
- Deliver lists of identified false positives to the Kepler archives at NExScI and MAST.
- Maintain the quality and integrity of the false positive flags on the Kepler Exoplanet Archive (NexScI), including regular re-vetting using additional data as appropriate.
Star Properties Working Group (STAR)
POC: Jaymie Matthews, University of British Columbia,
POC: Marc Pinsonneault, Ohio State University
Fundamental stellar properties are required for the determination of planet properties and for quantifying the sensitivity biases that affect the calculation of planet occurrence rates. The Star Properties working group acts as an advisory body for issues related to stellar characterization and the determination of fundamental stellar properties. Specific topics include:
- Assess the systematic errors in the stellar properties provided in the Kepler Input Catalog.
- Provide recommendations to the project on the best strategy for adopting properties of all Kepler target stars and deliver regular updates of star properties to the Kepler Science Office for use as input to the pipeline analysis software and the light curve modeling that leads to planet properties.
- Provide recommendations to the Kepler project on the optimization of follow-up resources for the goal of characterizing the Kepler target stars. Recommendations are communicated to the Follow-up Program (FOP) Coordinator before the start of the Kepler observing season.
- Provide recommendations to the Kepler project on the down-select of targets in the extended mission based on the revised stellar characterizations produced by the working group.
Kepler Asteroseismology Investigation
POC: Ron Gilliland, Penn State
The Kepler Asteroseismic Science Consortium (KASC) is a large and unique scientific collaboration, around which the asteroseismic analysis of Kepler data has been arranged since the beginning of the Mission. The structure of KASC fosters wide-ranging collaborations between research groups around the world, and provides an environment in which young postdocs and PhD students can easily forge new links and contacts. KASC is divided into ten working groups, each focusing on the analysis of different classes of pulsating stars. Members of KASC have access through the Kepler Asteroseismic Science Operations Center (KASOC) database to all Kepler data as soon as those data are made available in the KASOC. The database contains data that can also be found via the Mikulski Archive for Space Telescopes (MAST). In addition to the raw data, KASC-‐corrected/modified data, stellar models, stellar parameters (estimated by KASC), ground-‐based data (raw and reduced) and KASC publications are also made available to members. Visit the KASC website
for more information, including how to become a KASC member.
Transit Timing Variations and Multiple-Body Working Group (TTV)
POC: Jack Lissauer, NASA Ames Research Center
The scientific goals of the TTV working group are to characterize planetary systems, measure the distributions of important system parameters using the Kepler data, and estimate important quantities pertaining to Earth-size planets. The detection and analysis of transit timing variations is a means of confirming the planetary nature of a transiting object identified in Kepler data. Confirmation of Kepler's exoplanet candidates ultimately leads to higher catalog reliability and/or a quantitative assessment of that reliability. Full dynamical modeling of transit timing variations yields planet mass which, together with the planet radius produced by light curve modeling, yields planet density. The density distribution of small planets is of interest in understanding what fraction of Kepler's Earth-size planets are rocky. The TTV group also works to understand the sample statistics and architectures of multiple planet systems.
Eclipsing Binary Working Group (EB)
POC: Andrej Prsa, Villanova University
Kepler's core objective is to detect and characterize extrasolar planets, with a special emphasis on Earth-sized planets in the habitable zone (ηEarth). To support the core Kepler mission, the Eclipsing Binary Working Group is tasked with the following goals, in the order of priority:
- Maintain the catalog of eclipsing binaries in the Kepler field, including their ephemerides, the derived properties via automated methods, the geometric properties (eclipse widths, depths and separations), and any additional signal (ellipsoidal variability, eclipse timing variations, tertiary events, multiple periodicities); to find statistical properties of EBs: spatial distributions, multiplicity and orbital properties (eccentricity distributions);
- Determine the occurrence rate of false positives in the KOI catalog, including background (faint) eclipsing binaries that contaminate the target's photometric aperture as well as foreground (bright) eclipsing binaries that bleed into the target’s aperture; and
- Detect, validate and analyze circumstellar and circumbinary planets via tertiary events and eclipse timing variations.