``Lost'' TNOs and Centaurs

This page was intended to provide information of attempts to recover possibly lost TNOs and Centaurs. In this case, ``lost'' means that either (1) the uncertainty in the ephemeris is large because it has been a few years since the object has been observed, and/or (2) recovery observations have been attempted but have failed to locate the object. This list is intended to include objects for which recovery attempts have failed, and does not include objects that have no reported attempts since the last successful observation.

Although feedback has indicated that observers would find such a reference useful, people have not submitted reports, partly because of time constraints. This page is now effectively ``inactive'' until new interest is generated, and perhaps the format is made easier for submission.

However, this page is retained as an example of its past use.

The objects are listed in order of their designations, and details of the failed recovery attempts are given as a guide to observers for additional attempts. For example, if from the list below it seems likely that a given observation went faint enough that it should have seen the object, then an observer may want to try new observations ahead or behind the nominal track. (Of course, there is the possibility that the quoted limiting magnitudes are incorrect, or that the object was in the field but obscured by a star or galaxy, or the quoted coordinates are incorrect, etc.; so providing accurate information is essential.)

A simple template is available to report the information.

Additional information about current uncertainties of orbits can be obtained from Marc Buie's KBO Followup page, including this list of

Notes on table:

Position of Field
Position relative to the nominal ephemeris published by the Minor Planet Center, e.g., centered (the field was centered on the nominal position), 10 arcmin east, etc.
Limiting Magnitude
The contributing observer's estimate of the effective limiting magnitude that they should have been able to recover a moving object. This definition certainly varies from observer to observer, and is the largest uncertainty when trying to establish if an object actually should have been found or not.
Observer (with e-mail link) and Notes
This information is optionally provided by the contributing observer. In particular, the Notes can contain a link providing more details about the observations. Observers are strongly encouraged to provide as thorough details as possible for each observation. If possible, use this template to report your information.

Object Date of Observation Position of Field FOV [arcmin] Limiting Magnitude Observer Notes
1995 GA7 2000 March 29-30 modified ephemeris 10x10 24.0 Parker details
1997 CW29 1999 Dec 28-29 centered 10x10 23.1 Parker details
1998 WZ24 1999 Dec 29-31 centered 10x10 23.0 Parker details
1998 WZ24 2000 Jan 1-5 centered 9.4x9.4 23.3 Allen .
1999 CP133 2000 Jan 1-5 centered 9.4x9.4 23.3 Allen .

The Distant EKOs newsletter and web pages are managed by Joel Parker

Send e-mail to: ekonews@boulder.swri.edu