DOI: 10.5281/zenodo.15758360
title: The UltracoolSheet: Photometry, Astrometry, Spectroscopy, and Multiplicity for 4000+ Ultracool Dwarfs and Imaged Exoplanets

description: The UltracoolSheet is a catalog of 4000+ ultracool dwarfs (spectral types M6 and later) and imaged exoplanets, including photometry, absolute astrometry, proper motions, parallaxes, multiplicity, spectroscopic classifications, memberships, and ages.

The catalog lives in a Google spreadsheet at

      http://bit.ly/UltracoolSheet

where it will receive future updates.  The README tab in the spreadsheet contains a detailed description of the contents of the catalog.

UltracoolSheet started as a catalog of all spectroscopically confirmed objects of spectral type L0 or later in the extended solar neighborhood (out to ~100 pc) that were known as of April 15, 2015.  It has subsequently been extended to include many late-M dwarfs and also augmented with more recent discoveries spanning all ultracool spectral types.

The component spreadsheets of UltracoolSheet are posted here as CSV files, along with summary figures and (.dat) files containing ASCII tables to simplify figure plotting for users. The Summary Plots.pdf file shows the sky map, age distribution, publication dates, and proper motion since publication for all objects in UltracoolSheet, as well as the distribution of projected separations of companions.

When using data from the UltracoolSheet, please cite the individual papers from which the data comes. Citations codes are included for all the data in the tables, and the References table translates the citation codes into ADS bibcodes, Papers citekeys, and publication titles.

For research that benefits from this compilation, please cite this Zenodo post and include the following acknowledgment:

"This work has benefited from The UltracoolSheet at http://bit.ly/UltracoolSheet, maintained by Will Best, Trent Dupuy, Michael Liu, Aniket Sanghi, Rob Siverd, and Zhoujian Zhang, and developed from compilations by Dupuy & Liu (2012), Dupuy & Kraus (2013), Deacon et al. (2014),  Liu et al. (2016), Best et al. (2018), Best et al. (2021), Sanghi et al. (2023), and Schneider et al. (2023)."

The UltracoolSheet itself can be cited by this Zenodo DOI: 10.5281/zenodo.4169084  

Questions, comments, suggestions, or contributions?Please send them to ultracool.sheet@gmail.com (especially contributions!)

 
description: Version 2.0.2 (released 2025-06-27)



Updated Gl 229B with discovery of its binarity.

Added parallaxes and proper motions from Fontanive et al. (2025) and Albert et al. (2025).

Added photometry from Leggett et al. (2017).

Corrected the Spitzer ch1 photometry for WISE J073444.02-715744.0 (Kirkpartrick et al. 2021).

Added CatWISE and WISE All-Sky (for W3 and W4) data for WD 0806-661B.


Version 2.0.1 (released 2024-12-14):



Updated the age classifications for WISEA J114724.10-204021.3, HIP 81208 B, HIP 81208 Cb, S Ori 70, S Ori 73, and S Ori J053804.65-021352.5.

Added "v-red" flag to 2MASS J11193254-1137466.


Version 2.0.0 (released 2024-02-04) contains multiple significant updates to the UltracoolSheet since its initial release in November 2020. The main highlights are:

ADDITIONS





We added ~1000 objects in total.




We provide age estimates for all objects.




We now include L’-band and M’-band MKO photometry.




We added more binaries from Gaia and the literature, intending for UltracoolSheet to be complete for binaries and triples with a >=M7 primary.




We added more directly imaged companions with photometry/spectra.




We provide a more homogeneous selection of radial velocities from Gaia DR3 and the literature.


We include links to the SIMPLE database for objects appearing there, as well as the GUCDS shortname for objects in that catalog.


UPDATES





We replaced Gaia DR2 with DR3.




We replaced AllWISE with CatWISE2020, but retained AllWISE data that CatWISE did not update (e.g., W3 and W4 bands).


We added substantially to YJKH-band MKO photometry, mostly from the UKIDSS and UHS surveys and additional synthetic photometry.



We added substantially to Spitzer photometry from the literature.




We updated the SIMBAD and BANYAN Sigma data.




Some columns have changed names (see below).



TWO VARIANTS OF THE MAIN SHEET

We are releasing two forms of the Main tab in UltracoolSheet:





Main contains 3,890 objects for which the UltracoolSheet data is complete. (Including companions for binaries and triples, this grows to 4,076 objects.)




Main - In Progress contains everything in Main plus 67 additional objects (all in the Pleiades) for which the UltracoolSheet data is incomplete, for a total of 3,957 objects.



More details can be found in the  "Summary_of_changes_v2.pdf" document below.