There are currently 2,542 observatories that have MPC codes, two of which were added recently: V44 - Coyote Watcher, Pie Town, US/New Mexico and Y78 - Tros Alt - Spain, both operated by amateur astronomers. The parallax constraints and longitude in the MPC List are converted to 0.001 arc second precision.
Our list is inspired by the work of astronomer Bill Gray who maintains his own list at Project Pluto. He has corrected some of the geographic coordinates in the MPC List that one can see here, some of which the MPC has acknowledged and corrected in their own file, and some it looks like they haven’t. Also, he’s added probably 200 more observatories that the MPC has not yet added to their list. Over the next couple months, I’ll update our list to reflect some of his corrections and additions, as well as his computations of geodetic latitude for the whole list of observatories. I’ll also add MPC, GeoHack, and Project Pluto links to the updated file.
I prefer the geodetic latitude of an observatory when erecting discovery charts of objects, and the charts posted in the Planetary Discoveries section have this instead of geocentric latitude. Astrologically, it makes only a very slight difference in the Ascendant calculation, so not enough that most astrologers might be concerned with. The main concerns should be with using the MPC observatory coordinates, not those from an Atlas, along with the proper discovery date, time and place as shown at MPC, not from anecdotal or Wikipedia sources.
Keep reading with a 7-day free trial
Subscribe to The Future of Geocentric Astrology to keep reading this post and get 7 days of free access to the full post archives.