Monroe Pattillo

Used NASA Horizons web site to produce an osculating ephemeris report for JWST. Transcribed the Stellarium expected report data items into a new from scratch Stellarium asteroid .ini text file. Be sure to set the Horizons option to produce semimajor axis distance value in AU and not km, otherwise convert the km value to AU. The add/replace JWST as a user defined asteroid by opening the file from the Solar System Editor plugin. This approach doesn't crash Stellarium, and doesn't produce calculation errors as is the case with TLE loading. For me the Stellarium calculaton errors was why JWST didn't appear in the list (set filter to look for errors). The error is why I chose the user defined asteroid route. The error (and maybe crashing) might be because JWST has left Earth orbit, is on an open trajectory, and is essentially orbiting the Sun. JWST is essentially not orbiting the Earth as a satellite would and would make use of TLEs. The end result for me is a Stellarium planetarium position display that is reasonably similar between Heavens-Above (as a satellite) and Starry Night Pro as a user defined heliocentric asteroid. Have not had a clear night for target confirmation via telescope. Stellarium brightness is way off (89) likely due to Radius parameter being set as 2 for lack of knowing an accurate value. Once JWST is in the Stellarium database as an asteroid you can search for it as an asteroid, can center on it, and can track it. This means that an integrated telescope mount should be able to be command to slew to it. JWST is on a reasonably free trajectory. Do not expect a sidereal tracking mount to follow it. To lock onto it would likely require optical image tracking software. Try locking onto a dim star in the field and periodically snapping field images wide enough to include JWST and use them to create a time lapse. Due to the calculated magnitude being way too dim JWST will not appear until the field of view is zoomed up most of the way. Maybe a larger texture map might help, the nomap.png default seems to work. And disable the asteroid magnitude limit filter. An updated .ini fill will need to be produced once JWST does its MCC-2 rocket burn to put it into its Sun-Earth L2 halo orbit. An updated .ini file will need to be produced about every 60 days thereafter as JWST reaches the limits of its L2 halo ellipse and does a course alteration (momentum wheel and/or burn) to turn it back the other direction.

In Stellarium (am using version 0.21.3) select side bar Configuration Window, Plugins tab, select Satellites plug-in, click configure button, on Satellites tab set the search filter dropdown to [orbit calculation error] and JWST will appear (no indication as to what the error might be). I tried using both the initial and the current (2021-12-30) TLEs from Celestrak (which are different, likely due to MCC-1b burn) and no joy. JWST is on what might be described as an extremely elongated Earth orbit and Stellarium (as well as Starry Night Pro Plus 8 ) doesn't know what to make of its TLEs. The NASA JPL Horizons system knows how to track deep space (non-Earth orbiting) spacecraft. It will produce a report (UTC times). You can transcribe the coordinates in that report into planetarium apps as a centering target. Tracking is another issue. Wonder what the commonly used planetarium apps will do once JWST enters its Sun-Earth L2 halo orbit station where it will be orbiting essentially nothing.