The Known Solar-System Object Possible Associations List is a compendium of asteroids, comets, planets or planetary satellites, with orbits known at the time of WISE first-pass data processing, that were predicted to be within the field-of-view at the time of individual WISE Post-Cryo exposures. Individual objects were observed multiple times, so may have multiple entries in the list. When the predicted position of a solar system object is in proximity to a detection in the WISE single-exposures, the WISE source position and brightness information are also provided.
CAUTION: This is not a vetted list of solar system object detections. For a reliable, well-vetted list of WISE solar system object detections, please use the Moving Object Tracklets.
Users are strongly encouraged to read the Cautionary Notes to understand the limitations of the Known Solar-System Object Possible Associations List.
The following table contains brief descriptions of the parameters provided for each record the WISE Post-Cryo Data Release Known Solar-System Object Possible Association List.
The columns in the following table are:
|cntr||%10d||----||no||Unique identification number for the Atlas Image Frame Cross Reference table entry created sequentially in the order of the Archive load processing.|
|objid||%36s||----||yes||Solar System Object (SSO) identifier. The identifier field may contain any combination of MPC number, object name (e.g., Ceres), and (provisional-)designation; comets and planets have no MPC numbers.|
|t||%1s||----||yes||Type of Solar System object:
|ra||%10.6f||deg||yes||Predicted Right Ascension (J2000) of SSO at time of WISE observation.|
|dec||%10.6f||deg||yes||Predicted Declination (J2000) of SSO at time of WISE observation.|
|mu||%7.3f||arcsec/sec||yes||Predicted proper motion of SSO at time of WISE observation.|
|theta||%5.1f||deg||yes||Direction of predicted proper motion (E of N) of SSO at time of WISE observation.|
|emj||%4.1f||srcsec||yes||Semimajor axis of the error ellipse of the SSO predicted position.|
|emn||%4.1f||arcsec||yes||Semiminor axis of error ellipse of the SSO predicted position.|
|erang||%5.1f||deg||yes||Position angle of emj axis (E of N).|
|rhelio||%9.5f||AU||yes||SSO heliocentric distance at the time of the WISE observation.|
|rtopo||%9.5f||AU||yes||SSO Topocentric (spacecraft) distance at the time of the WISE observation.|
|phase||%7.3f||deg||yes||SSO phase angle at the time of the WISE observation.|
|amag||%5.2f||mag||yes||SSO absolute magnitude.|
|vmag||%6.3f||mag||yes||SSO predicted visual magnitude at the time of the WISE observation.|
|slope||%5.2f||----||yes||Slope parameter for computing phase-dependent term in visual mag|
|perdist||%10.7f||AU||yes||SSO perihelion distance at the time of the WISE observation.|
|ecc||%9.7f||----||yes||SSO orbital eccentricity|
|incl||%12.8f||deg||yes||SSO orbital inclination|
|pv1||%11.8s||----||yes||SSO orbit P vector (unit vector of Sun toward perihelion) X component|
|pv2||%11.8f||----||yes||SSO orbit P vector (unit vector of Sun toward perihelion) Y component|
|pv3||%11.8f||----||yes||SSO orbit P vector (unit vector of Sun toward perihelion) Z component|
|qv1||%11.8f||----||yes||SSO orbit Q vector (unit vector orthogonal to P in orbit plane, right-handed about orbital angular momentum vector) X component|
|qv2||%11.8f||----||yes||SSO orbit Q vector (unit vector orthogonal to P in orbit plane, right-handed about orbital angular momentum vector) Y component|
|qv3||%11.8f||----||yes||SSO orbit Q vector (unit vector orthogonal to P in orbit plane, right-handed about orbital angular momentum vector) Z component|
|pertime||%13.5||mjdate||yes||SSO orbit perihelion passage time, modified Julian date|
|err||%4.1f||----||yes||SSO orbital element quality estimate|
|mjd||%12.6f||mjdate||yes||Modified Julian date of the mid-point of the observation of the frameset within which the FOV the SSO is predicted to fall.|
|scan_id||%6s||----||no||Identifier of the WISE survey scan in
which the predicted position of this SSO was was observed.
Scan_id is a six character string that identifies a block of survey exposures that are acquired between two flight system maneuvers, such as reorientation of the instrument boresite near the ecliptic poles, or slews to acquire TDRSS for data downlink contacts. Because maneuvers often take place near the ecliptic poles, the scan number is roughly associated with a half-orbit's worth of images. However, scans can cover less or more than half of the arc between ecliptic poles.
The scan_id has the general form SSSSSx, where
The first scan whose data are used in the Post-Cryo Data Release is scan 08745a. This was the first scan after the SEP crossing in the 4372nd WISE orbit. The final scan included in the Release is 12514a, the first scan after the NEP crossing in the 6257th WISE orbit.
|frame_num||%3d||----||no||Number of the Single-exposure frameset within
which lies the predicted position of the SSO during the WISE observation.
Frame_num has the general form MMM, a zero-filled three-digit number.
The frameset number is computed based on time bins which count from the scan start time:
For example, a frame with a start time 1234 secs after the scan start time would have a frame number of 124.
|source_id||%16s||----||yes||Identifier of the Post-Cryo
Release Single-exposure Database
source extraction that is spatially associated with the SSO predicted
position at the time of the WISE observation.
CAUTION: A spatial association between the predicted SSO position and the position of a WISE Single-exposure extraction does not necessarily mean that this is a WISE detection of the SSO. The Single-exposure Source Database contains a significant number of spurious detections of noise excursions, transient pixel events and image artifacts. Thus the spatial coincidence between the SSO position and WISE extraction may be a chance alignment with a spurious extraction or an inertial background astrophysical source. See IV.4.iv.1 for suggestions for identifying spurious associations.
This column is "null" if there is not a WISE Single-exposure extraction spatially associated with the predicted position of the SSO.
Source_id has the general form SSSSSxMMM-IIIIII, where
|mconf||%6.2f||----||yes||Spatial association match confidence: 2-D chi-square parameter, max 99.99, -9.99 if no association|
|n||%1d||----||yes||Number of WISE Single-exposure extractions within association threshold (max 9), 0 if no association|
|dra||%6.1f||arcsec||yes||RA distance between associated WISE extraction and predicted SSO position (WISE - SSO).|
|ddec||%6.1f||arcsec||yes||Declination distance between associated WISE extraction and predicted SSO position (WISE - SSO).|
|w1mpro||%7.3f||mag||yes||Single-exposure W1 profile-fit magnitude or magnitude upper limit for the WISE extraction spatially associated with the SSO. The column is null if there is no associated WISE extraction.|
|w1sgmp||%5.3f||mag||yes||Single-exposure W1 profile-fit photometric measurement uncertainty for the associated WISE extraction. This column is null if there is no associated WISE extraction, or the W1 profile-fit magnitude of an associated extraction is a 95% confidence upper limit.|
|w2mpro||%7.3f||mag||yes||Single-exposure W2 profile-fit magnitude or magnitude upper limit for the WISE extraction spatially associated with the SSO. The column is null if there is no associated WISE extraction.|
|w2sgmp||%5.3f||mag||yes||Single-exposure W1 profile-fit photometric measurement uncertainty for the associated WISE extraction. This column is null if there is no associated WISE extraction, or the W2 profile-fit magnitude of an associated extraction is a 95% confidence upper limit.|
|x||%19.16f||----||yes||unit sphere (x,y,z) position x value|
|y||%19.16f||----||yes||Unit sphere (x,y,z) position y value|
|z||%19.16f||----||yes||Unit sphere (x,y,z) position z value|
|spt_ind||%9d||----||yes||HTM spatial (x,y,z) index key|
Last Updated: 2013 May 20