Fig 1: An example light curve from the Q3 dropped target list.
The source is KepID 2019258 with Kp = 11.86 and (g − r) = 1.97, a likely red giant.

During its early operational phase, the Kepler target list contained some stars with uncertain classifications and unknown variability. From Quarters 0 through 3, a number of stars were dropped from the exoplanet survey each quarter because they did not meet the criteria for hosting Earth-sized detectable planets within the habitable zone. All data for Q0, Q1 and Q2 are now public; the nominal release date for the entire Q3 dataset is June 2012. Until the Q3 public data release, the Q3 Dropped Targets remain a distinct public resource.

During the 89 days of Quarter 3 (Q3), Kepler observed 166,685 sources ranging from 7.0 < Kp < 19.0. A sub-sample of Q3 sources, N=5292, were subsequently dropped from the exoplanet survey list for the following reasons:

1. Target selection criteria (for example the source crowding metric) were updated between Q3 and Q4 based upon operating mission experience.
2. Selected targets fainter than 15th mag were dropped from the list.
3. Selected targets with a minimum detectable planet radius larger than 1 Jupiter radius were dropped. For this sample of stars, the minimum detectable planet radius was computed using observed noise characteristics as opposed to noise levels estimate prior to launch.
4. Selected variable targets that have proved to be unsuitable for exoplanet detection.

The Q3 dropped target list contains both long cadence and short cadence data. After Q3, no further targets have been dropped from the exoplanet survey. Any future dropped targets made public will be announced on these pages. Calibrated data for individual sources can be obtained from the Kepler Archive at MAST using the Dropped Target List. Q3 data properties are described in Data Release Notes #4.

Although all Q0-2 data is now available, users may find the subset of explicitly dropped targets useful. The number of dropped targets for each quarter is given here:

Instructions for identifying the specific sources in these dropped target lists are given below.

Potential Guest Observers can use this set of time series data to inform future proposals. Dropped targets can be proposed for further observation in future Guest Observer cycles, through the Discretionary Target program, and by joining the Kepler Asteroseismology Consortium. These data are also available for analysis under NASA's Astrophysics Data Analysis Program. Interested parties are strongly encouraged to inspect the public Kepler data and consider Guest Observer, DDT, KASC and ADAP proposals.

Please direct questions concerning dropped targets or any public data to the .

BROWSE DROPPED TARGETS

• Go the Dropped Target List page at MAST, which provides individual links to the target information and light curves for the Q3 dropped targets.
• Alternatively, navigate your browser to the Kepler Data Search and Retrieval Page.
• Fill the 'Release Date' field with '< 01-May-2010'.
• From the pull-down menu next to 'User-specified field 1', choose 'Quarter', and enter '3' in the dialog box.
• Click the search button.
• To identify dropped targets from quarters 0-2, users can select "Quarter" in the 'User-specified field 1' drop-down menu, and enter 0, 1 or 2 into the quarter into the adjacent dialog box. By using release date mentioned above, targets dropped before the large public releases can be identified.

QUICK LINKS

• Data Release Notes #4 (Quarter 3)
• Kepler Data Search and Retrieval form
• Search and Retrieval Form help page
• Kepler Archive Manual