Observing a minor planet with RTS2

As of May 4 2018:

To observe a minor planet, make a new target by running rts2-newtarget. When it prompts for name, RA/Dec, etc, paste in the minor planet ephemeris in MPEC format, like this, all on one line:

00021 7.35 0.11 K183N 240.62102 249.91805 80.87133 3.06377 0.1640975 0.25933042 2.4353819 0 MPO445254 4448 71 1866-2018 0.39 M-v 38h MPCLINUX 0000 (21) Lutetia 20180425

Then type 's' at the prompt to save it, hit return to let rts2 choose a new target id, and give it a name, eg "Lutetia". To set the filters, exposure, etc, create a file in the bigpop:~rts2obs/.rts2scripts directoty, named Lutetia.json. Try copying one of the existing json files to see the format. To add the object to the queue, as for any other target, run:

rts2-queue --queue plan <target-id> (where target-id is the number that RTS2 assigned, like 1201).

Ephemerides for minor planets can be found at https://minorplanetcenter.net . For example https://minorplanetcenter.net/iau/Ephemerides/Bright/2018/index.html for bright asteroids, or https://minorplanetcenter.net/iau/MPEph/MPEph.html to search for an ephemeris by name of object (choose "MPC 1-line" in the output format selector at bottom of that page).

To generate a table of RA/Dec, RA/Dec tracking rates, estimated magnitude, etc, you can use the interface at JPL Horizons, https://ssd.jpl.nasa.gov/horizons.cgi . This is not necessary for input to RTS2 but is useful to check the RA/Dec, rates, magnitude, etc.

Currently it works as: rts2 is acquiring the object in RA,Dec at beginning of each observation set and passing the correct RA, Dec to TCS. This means that it is pointing correctly at the object at start of the set of exposures, but the objects will move during each individual exposure and also during the exposures that make up an observation. That is, if your script asks for 3x300 sec exposures, the object will be acquired once in RA,Dec at the start of the set, but bias rates are not applied to tracking, so the object will be trailed in exposures and will move between exposures. However, if you requeue the observation, it will re-compute the object RA,Dec and acquire it correctly. Thus if you wanted to take a large number of short exposures, you could do it by defining the observation to contain 1 exposure, and requeueing it many times. See https://github.com/bjweiner/ARTN/wiki/Defining-an-RTS2-observing-script-for-a-target for how to define and manage this requeueing.

Having the bias rates computed and sent to TCS, so that it correctly tracks the non-sidereal object, is under development.