The Kepler Mission will achieve a photometric precision of 20 parts per million (ppm), including all noise sources: Gaussian noise, stellar variability and instrument noise, on a V = 12 magnitude G2V star integrating for 6.5 hours after differential ensemble processing. The mission will continuously monitor 100,000+ stars for 4-6 years with 15 minute temporal resolution. The field of view (FOV) of more than 100 square degrees is located in the Cygnus region. The same FOV will be continuously monitored throughout the entire mission. The nominal magnitude range of Kepler is between 9th and 15th apparent V-magnitude, although targets as faint as V = 18th magnitude may be considered for guest observer use. The bandpass is broadband from 400 to 900 nm. The point spread function is about 12 arc seconds in diameter (FWHM). The baseline mission is four years long with a planned option for an additional two-year extension. The resulting data base will be unique given the photometric precision, duration, contiguity and number of stars. The community will have the opportunity to mine this rich data set for astrophysical phenomena not included in the baseline Kepler Mission.

The community may propose to monitor additional objects of any nature that are in the Kepler field of view (FOV) located in the Cygnus region, such as, variable stars or active galactic nuclei. The community must propose the additional objects of interest to observe, since data from objects that are not on the Kepler target list are not telemetered to the ground and archived. Only the pixels making up a target star are saved from the CCD on the satellite. The entire CCD images are not routinely recorded. The list of additional objects may be modified as often as every three months.

Click on the button to see if the RA and Dec of an object falls on an active CCD in the FOV.

Download a pdf copy of the FOV map.

In addition to those stars being monitored for planets, up to 3,025 targets at any one time may be selected for guest observing based on peer reviewed proposals. GO targets may be changed at an interval of 3 months. The time resolution is 15 minutes for 3000 targets and 1 minute for 25 targets at any given time. The targets must be within the Kepler FOV. The Kepler FOV will not be moved to accommodate a GO request. Objects somewhat brighter or fainter than the nominal magnitude range may still be useable. Objects that are already on the Kepler target list will be referred to the DAP (see below). The final Kepler target list may not be known until shortly before launch.

Size and orientation of the CCD modules in the Cygnus constellation
The FOV center is at RA 19h22m40s Dec 44°30'00"

Any object within the FOV of the Kepler Mission may be proposed for observation. These objects may be intrinsically variable stars, such as, pulsating (Cepheids, RR Lyrae, Mira, etc.), rotating (ellipsoidal, etc.), eruptive (T Tauri, Wolf-Rayet, etc.) and explosive (novae, super-novae, cataclysmic variables) or extrinsically variable, such as, eclipsing binaries. The targets may also be extragalactic, such as, AGNs and quasars.

Observations of an approved target will typically be continued for three months to a year. However, if approved by the peer review committee, observation of a particular target may continue up to the entire life time of the Kepler Mission, subject to an annual review. Considerations will be made in scheduling for coordinated observations with either ground-based or other space-based observatories or for times of predictable phenomena.

The data from the Kepler Mission will be processed and archived at the Space Telescope Science Institute (STScI). The data will be calibrated. Bias (dark level) and smear (the photometer has no shutter) will be removed and values converted to fluxes. The multiple pixels making up a single star's psf will not be combined, permitting users to perform their own photometry or other forms of analysis. In addition, light curves for all the stars will be processed on a quarterly basis at NASA Ames Research Center. Ensemble-normalized light curves will be placed in the archive; there may be a quarter year lag for processing. The STScI will provide support to the GO users through the Multi-mission Archive Support Tool (MAST). Users will be able to search data bases to ascertain what data exists on targets of potential interest, and to determine when specific observations will be available (consistent with proprietary restrictions) for access. GO users (as well as unfunded users) will have access to data in a convenient form via internet.

The GO will be supported at the Data Management Center at STScI through creation of documents, web pages, and online tools that thoroughly describe the photometer, the expected attributes of data provided by Kepler and a guide to the extensive photometric information developed from ground-based studies of objects in the field of view. Proposers may use these to estimate signal-to-noise ratios for possible targets, determine what observations exist for DAP, and may thus best plan their proposals. Limited support will be provided to answer questions about data analysis.

After the end of the mission, the STScI will perform a final processing to calibrated units using the latest calibration information for the whole mission. The light curves for all of the stars for the full duration of the mission derived by the Kepler science team will also be added to the archive. These curves will have included differential ensemble normalization. The Kepler archive in MAST is expected to be supported for ten years after the end of mission.

Note that the GO Program is still in the formative stages. Any comments are appreciated and will be considered. The contact person for the GO Program is:
Dr. Pamela M. Marcum <pamela.m.marcum@nasa.gov>