MPChecker: Minor Planet Checker

Use the form below to prepare a list of known minor planets in a specified region. Notes on using this form are given at the bottom of this page.

If you wish to report the non-functioning of (or errors in) this service, please use this feedback form. But ensure that you have seen this note on computing limits before reporting anything.

Date : UT

Produce list of known minor planets around:

this J2000.0 position: R.A. = Decl. =

or around these observations:

Radius of search = arc-minutes

Limiting magnitude, V =   Observatory code =

Output matches in order of:

increasing distance from specified position    increasing Right Ascension

Display motions in arcseconds per minute or hour
or degrees per day
Display total or separate motions

Output designations in unpacked or packed form

all objects
just those flagged as needing observations
just numbered objects
just unnumbered objects
just those nearly-numberable unnumbered objects

Don't include planets and irregular outer satellites
Include planets and irregular outer satellites
Include ONLY planets and irregular outer satellites

Return: plain HTML page or MPES-aware HTML page

Useful Tips

We hope that the information given below will be useful in helping you to use the minor-planet checker form properly.
The date to be entered is the UT date of your observation (given to 0.1 or 0.01 of a day). The default is now. The date should be within two years of the present. If you have an older suspect you wish to check, please contact the Central Bureau for Astronomical Telegrams (for novae and supernovae) or the Minor Planet Center (for minor planets).

Absolute Position
The J2000.0 right ascension should be entered in one of the following forms: HH MM; HH MM.d; HH MM.dd; HH MM SS; HH MM SS.d; or HH MM SS.dd. HH represents the hours, MM the minutes, SS the seconds and d/dd any decimal part of the minutes or seconds. Leading zeroes are to be given when any quantity is less than 10.

The J2000.0 declination should be entered in one of the following forms: sDD MM; sDD MM.d; sDD MM.dd; sDD MM SS; or sDD MM SS.d. s represents the sign (`+' or `-', must be given), DD the degrees, MM the minutes, SS the seconds and d/dd any decimal part of the minutes or seconds. Leading zeroes are to be given when any quantity is less than 10.

Some examples of valid input follow.

  • If the position you wish to search around is 7h13.7m, -14°2', you would enter `07 13.7' and `-14 02' in the relevant boxes
  • If the position is 14h3m8s, +1°48'.3, you would enter `14 03 08' and `+01 48.3'.

One or more 80-column observation records can be typed or pasted into the writable icon. The date of the search, central position and observatory code will be taken from the observation record. Multiple observations of the same object will be reduced to a single observation. If you are entering search fields, rather than observations, ensure that each search field has a unique "designation".

Radius of search
The default setting of 15 arcminutes is thought to be appropriate for the standard amateur setup, considering the motion of main-belt asteroids. It may be lowered (down to 5 arcminutes) or raised (up to 300 arcminutes) as desired. If your specified radius exceeds the maximum allowable radius, the maximum value will be used.

Limiting magnitude for search
The default setting of V = 20.0 may be changed as necessary. Note that you should set this value to be at least 1.0 magnitude fainter than your telescope's limiting magnitude to allow for poorly-known minor-planet magnitudes.

Observatory code
By default, the calculation is performed for the geocenter (code 500). If you wish to do the calculations for a specific site, enter the appropriate observatory code in the writable icon.

By default all types of objects are searched for. By selecting other options you can restrict the search to just numbered or unnumbered minor planets or nearly-numberable minor planets. If this latter option is chosen, the maximum search radius is 900 arcminutes. It is important to remember when using the nearly-numberable option that the vast majority of the nearly-numberable objects are in fact numbered in the next batch of MPCs. This means that in the period immediately after MPC preparation there may be very few objects selected.

Computing Limits
Note that this form is not intended for checking large number of fields. There is a maximum limit for CPU time associated with this script. It this limit is exceeded, the job will be aborted. This prevents a handful of users running long lists of checks from clogging up the web server for other users. It is far more efficient to submit large batches of unidentified observations to the MPC for automatic processing than it is to try and id the objects through this service.

We are very pleased to acknowledge the support of Process Software Corporation and their excellent VMS Web server, Purveyor.

This service runs on the Tamkin Foundation Computing Network.