That's where the UltracoolSheet comes in. Being from 2020, it contains the results of several surveys from recent years; the number of objects is somewhat less than that of the older catalog, but given that many of its entries were unconfirmed, the quality of the data more than makes up for it.
The following is the result of using some spreadsheet magic to generate a Celestia add-on from the UltracoolSheet, which after filtering out duplicate entries from the default data files (plus the exoplanet catalog by Sirius_Alpha), results in a grand total of 2819 ultra-cool dwarfs, spanning from the late M-type main sequence stars, to L, T and Y-type brown dwarfs. Over a hundred of them are actually binary systems, and three are triple, rendered here with approximate parameters.
Given that the original source doesn't contain physical properties such as radii or visual magnitudes, these have been taken from other sources or estimated using the COND03 isochrones, with some guesses about the age of each dwarf (as an example, if it's known to be a member of a moving group). That yields decent results in many cases: for instance, young dwarfs become more inflated than older ones, which are more compressed.
- Pi1 Cancri appears to be flanked by its brown dwarf companions. The primary star also is itself a binary, too far away to be resolved
Limitations
- Since the last update of the UltracoolSheet, there are many recent discoveries which are missing. It's also very incomplete beyond 100 parsecs (that means no Teide 1, sorry
) - As just said, most physical parameters are guesses and may be significantly off in specific cases.
- Several of the dwarfs included here are companions to higher-mass stars, these not being dealt with here. As such, the distance values for them from other files may not match the ones of the companions, which can result in the components being separated by up to a few light-years. In some cases, the parent stars themselves may even be missing, if they're not bright enough to be in default Celestia!
- There may still be duplicates with other add-ons, especially if they don't use Modify/Replace.
For the future
- Many of the binary systems included here have determined orbits, yet those are currently not modeled here.
- Including some scripts for marking specific dwarfs (e.g. moving group members).
- And of course, here's hoping that the UltracoolSheet itself eventually gets an update!
ultracool.zip- (213.69 KiB) Downloaded 121 times
That's it! Now enjoy your new solar neighbors
