Calculating "Distance to Edge" and "Season-onCCD" Values
Calculations for "Distance to Edge" and "Seasons on CCD"
values have three slightly different definitions as
explained below:
Distance to Edge Values
- KIC Targets with defined Kepler Magnitudes -
Distances for this group are defined by the Kepler project
as the shortest distance from an edge of the CCD to a pixel in the
photometric aperture for a given season. Values of 0 or greater
are observable.
- KIC targets with undefined Kepler Magnitudes -
Distances were calculated by MAST staff and represent the
distance in pixels from the nearest edge of the CCD to the target
(i.e., not to the photometric aperture) for a given season. A value
greater than 0
would indicate a target is on the detector, but the required
aperture size may prevent it from being observed (e.g., for an
extended source).
- Non-KIC targets -
Distances are defined as the closest possible distance from the
target to the edge (for a given season) with a maximum absolute
uncertainty of 22 pixels (i.e.,
the target could be up to 22 pixels farther from, but not closer
to, the edge).
Number of Seasons on CCD
- For targets with a defined Kepler magnitude (about 4.4 million targets),
this represents
the number of seasons in which a project-defined distance is 0 or greater.
To see non-observable KIC targets, set the "Seasons on CCD" form element to
"unspecified".
- For those KIC targets with unknown Kepler magnitudes (roughly 120,000
targets), this represents
the number of seasons that MAST-derived distances (see above) are greater
than zero. As above, to see non-observable KIC targets, set the "Seasons
on CCD" form element to
"unspecified".
- For non-KIC targets (a total of roughly 7.8 million targets) , the number of
seasons with MAST-derived distances
greater than or equal to 4. Non-KIC targets must have at least one season on the detector to
be included in the database table so values will range from 1 to 4. Note because
of the 22-pixel uncertainty, some targets considered off the detector
in a given season may actually appear on the detector.