Getting observations into Find_Orb

There is a standard format for reporting observations of asteroids, comets, and satellites that is used by Find_Orb, the Minor Planet Center, and really most people working with determining orbits. It's somewhat clunky and quirky, and there is work afoot to replace it with a new format. However, the "current" format will be in use for some time.

The format dates back to the days of punched cards, so every observation has to be packed into 80 bytes. Here's an example of observations for a (made-up) object :

OBS P. Birtwhistle
TEL 0.30-m f/6.3 Schmidt-Cassegrain + CCD
ACK Example1 obs from October 1997
    Example1  C1997 10 13.74589 00 37 45.24 +03 53 36.5                      J95
    Example1  C1997 10 18.98362 00 30 24.50 +03 07 04.1                      J95
    Example1  C1997 10 20.72954 00 27 59.69 +02 51 39.0                      J95

    Example1  C1997 10 15.14055 00 35 48.03 +03 41 16.4                      691
    Example1  C1997 10 18.28119 00 31 23.44 +03 13 20.5                      691
    Example1  C1997 10 21.42177 00 27 01.54 +02 45 38.5                      691
    Example1  C1997 10 15.49183 00 35 17.54 +03 38 08.5          17.4 V      709
    Example1  C1997 10 17.23771 00 32 51.27 +03 22 37.8          17.5 V      709
    Example1  C1997 10 15.49119 00 35 18.30 +03 38 19.1          18.3 R      E12
    Example1  C1997 10 19.53242 00 29 38.74 +03 02 25.5                      E12

A few notes about this :

• The actual observations are the 80-column records. Each gives the object designation; the (UTC) time of the observation, in YYYY MM DD.DDDDD form; the right ascension at which the object was observed, in HH MM SS.SS form; the declination, in (sign)DD MM SS.S form; the magnitude, if it was measured (happened for three observations above); and the MPC observatory code. The other columns may be used as well; click here for details. If you get the times, positions, and MPC codes right, Find_Orb should be able to get an orbit. (MPC is much pickier; for them, the data must be rigidly formatted as above.)

Column alignment matters. I think this is the most common source of trouble. The lines must be 80 columns long, with the year in columns 16-19, the declination arcminutes in columns 49-50, and so on. (Actually, the problem is so common that I added some logic to Find_Orb to puzzle out the most common misalignments. But that logic is imperfect, and MPC will simply stare blankly at misaligned data.)

Click here for alternative RA/dec formats or here for alternative time formats. Note that these are Find_Orb specific. MPC will reject observations submitted in these extended formats.

• You may, or may not, include observational details headers. As an example, I made up a header for MPC code (J95). Do this, and the details will be used in the "observers" section of the pseudo-MPEC. If you're so inclined, you can add such headers for more than one observatory.

• The order of the observations is irrelevant. (They'll get sorted by date/time.)

MPC codes

In the above example, the "observations" came from the (real) observatories (J95) Great Shefford in the UK, (691) Spacewatch and (709) Cloudcroft in Arizona, and (E12) in Australia. The Minor Planet Center has a list of observatory codes, each with its own three-character identifier; if your observatory is in the list, you should use that code.

Click here if you aren't at a listed MPC observatory. Find_Orb provides several ways to specify a "temporary" observatory code: essentially, you make up a code and add a line telling Find_Orb where it is.

Contact info

I can be reached at p‮ôç.ötulpťcéjôřp@otúl‬m. If you're a human instead of a spambot, you can probably figure out how to remove the diacritical marks...