Version 4.0.0 of the Unified Astronomy Thesaurus

Today, we release version 4.0.0 of the UAT!

Updates and Changes

In addition to the usual updates and additions to concepts found in the Unified Astronomy Thesaurus, this update also brings with it some minor technical changes and updates that will hopefully help developers who are interested in implementing the UAT into their tools and platforms.

The largest content change this time would be the addition of over 850 definitions to UAT concept.  A few people have been asking for these for a while, and this was finally the year to make some good headway on this.  Almost all of these initial definitions were sourced from the Etymological Dictionary of Astronomy and Astrophysics, with a few being supplemented from other sources.  Definitions for the remaining two-thirds of UAT concepts will be coming in future releases as they can be sourced and vetted.

About 50 concepts were added, while about 25 were deprecated, bringing us to a total of 2122 concepts.  The additional concepts are mostly concentrated in the “Planetary science” branch, with some spill over into exoplanets.  Alternate labels, scope notes, and examples were also added to over 100 concepts, all of which improve usage of the UAT in automated systems.

Which leads me to those technical updates I mentioned earlier.  Deprecated concepts can now be found in the UAT_deprecatedConcepts.rdf file.  More usefully, I’ve gone back through that list of deprecated concepts and added “Use instead” notes for every single one, pointing back to one or more concepts that could be used in lieu of the original concept.  These notes are found as “changeNotes” in UAT_skosnotes.rdf.

As many developers (including myself) prefer working with json, I’ve also expanded the files available in that format.

  1. UAT.json should be compatible with systems that had been using the prior version of this file.  It contains the full UAT organized into a hierarchy, but now it contains a lot more information about each concept, including definitions, other notes, and related links.  It also has a section to list all the deprecated concepts and their suggested redirects.
  2. UAT_simple.json this is an updated version of the older UAT.json file.  It only includes the concepts and their URIs in a hierarchy.  I don’t expect this file to be very useful, but it’s here if anyone needs to work with a slimmed down file.
  3. UAT_list.json would be great if you need to look up information for a specific concept and don’t want to navigate through the whole hierarchy to find it.  Similar to UAT.json, this file contains all information available about each concept, but nothing is nested, and the deprecated concepts are listed right along with the active concepts.

Presentations and Events

In addition to our usual presence at the AAS Annual meeting, the UAT was visible at a few other events this year.

Stewardship and Impact of a Thesaurus for the Astronomy Community

I gave a poster presentation at the Special Libraries Association conference over the summer.  The poster and presentation recording along with additional information from that event can be found here.

Powered by the Unified Astronomy Thesaurus

Last year, Frank Timmes recorded four short videos introducing the UAT to the astronomy community.  This summer I followed up with him and we recorded three longer format videos discussing how to use the UAT, how authors can influence the uat, and how the UAT has been used in publications so far.  All seven videos in this series can be found in this playlist on YouTube.

Unified Astronomy Thesaurus Informational Webinar

Speakers from IVOA, STScI, AAS, and ADS presented on their implementations, current and planned, of the Unified Astronomy Thesaurus.  Slides are available here, and a video recording of the session should be added shortly.

Concluding Remarks

The Steering Committee wishes to thank those from the astronomy community who took the time to contribute feedback for improving the UAT.  We also wish to thank the American Astronomical Society for continuing to support the growth of the Unified Astronomy Thesaurus, especially the editors who provided feedback for proposed changes.

Katie Frey
UAT Curator

Version 3.1.0 of the Unified Astronomy Thesaurus

Today, we launched version 3.1.0 of the UAT!

This year has been an exciting one for the UAT; on June 3rd, the American Astronomical Society formally incorporated the UAT into its journal submission process.  The UAT has also been included in the most recent call for proposals for the Hubble Space Telescope. This uptake in usage and adoption has brought the UAT to the forefront of the community’s attention and, as a result, we have received fantastic and thoughtful suggestions submitted by authors and researchers looking for a better way to describe their work.  This update reflects many of those suggestions and we are looking forward to another great year of interaction with the astronomical community as we strive to improve the UAT.

Overall, the 3.1.0 update focuses on fleshing out two areas in particular (“Comets” and “Gravitational lensing”) as well as bringing a host of corrections and updates.  In total, 54 concepts were added to the UAT, 7 concepts were deprecated, the preferred label of 18 concepts were updated, and 51 alternative labels for concepts were added.  Preparing the 3.1.0 release has also given me a deeper appreciation for how the field of astronomy has changed and evolved over time.

As our understanding of the universe grows and changes, the words we use to describe that universe also grow and change.  For example, before we were able to bring galaxies into focus and understand what they were, astronomers used to consider galaxies as nebulous regions.  As our common understanding about the universe changed, as we were able to build better telescopes, and learn better methods of analyzing information, it became clear that some of these “nebulae” were actually full of many stars, and that they existed outside of our galaxy…and eventually we discovered they were galaxies in their own right.  As great as this story is, it doesn’t have a lot of modern resonance as most of us grew up knowing that there are other galaxies.

Occurrences such as these have become rare, and yet I found myself working through one as I prepared for the 3.1.0 release.  It all started when Dr. Dan Seaton from the University of Colorado commented on an Issue about Solar coronal regions that he “[did] not know what the M corona is supposed to be referring to.”  My first task was to figure out what the concept could be about, where did it come from, and why was it in the UAT in the first place.  I dug into the source vocabularies, discovering that the concept “M region” existed in both the IAU Thesaurus and the IVO Thesaurus. With those thesauri backing the concept up, it felt like it must have had some kind of scientific source.  So I ran a search in ADS for “M region” which yielded a very inconclusive results set of articles spanning oceanic fronts to magnetic fields to mud volcanoes to planetary nebulae.

Hoping to find relevant articles, I narrowed my search to “Solar M regions,” and, even with only 21 results, I could immediately tell I was on the right track.  Reading through the abstract, most of these articles seemed to be about the geomagnetic field, the aurora, or the Solar magnetic field… concepts that were at least a bit more connected than the previous search results.  The earliest article in the result list was from 1941, and even that refers to an earlier identification of Solar M regions.  The mystery deepened! Even though the concept seemed unheard of today, it clearly had been something in the recent past.  Twenty of the 21 articles identified by ADS were published between 1940 and 1980, with a single non-refereed reference in 2003.

It was an article from 1975 titled “The solar M-region problem – An old problem now facing its solution?” which finally solved the mystery.  In this article, Dr. Arild Gulbrandsen writes “….the solar M-regions should be identified with the central portion of magnetically open solar regions, or coronal holes.” I had found an answer: Solar M regions are now something astronomers identify as coronal holes! Both Dr. Seaton and Dr. Leon Golub (AAS Solar editor) agreed with my assessment.

In this release of the UAT the historical “Solar coronal M regions” concept was deprecated and merged into the already existent “Solar coronal holes” concept and now I have modern and tangible example of how our knowledge of astronomy has grown, changed, and evolved in modern language.

The Steering Committee wishes to thank those who took the time to make suggestions for improving the UAT. We also wish to thank the AAS for continuing to support the growth of the Unified Astronomy Thesaurus, especially  the editors who provided feedback for proposed changes.

As I close out this update, I want to draw attention to the Contributor Covenant Code of Conduct recently added to the UAT.  This is an open project and I want to emphasize that it is welcoming to all regardless of age, body size, visible or invisible disability, ethnicity, sex characteristics, gender identity and expression, level of experience, education, socio-economic status, nationality, personal appearance, race, religion, or sexual identity and orientation.  I am looking forward to working with the diverse astronomical community to continue improving the Unified Astronomy Thesaurus throughout the coming year and beyond!

Katie Frey
UAT Curator

Unified Astronomy Thesaurus v.3.1.0 Release Notes Summary

Version 3.1.0 of the Unified Astronomy Thesaurus consists of a polyhierarchy with 2097 concepts, 11 top concepts, a depth of 11 levels, with 586 related concept links.

 Release Date: 12/20/2019 

Overview of Changes

  • Contributor Covenant Code of Conduct has been added.
  • Minor revisions of two branches:
    • Gravitational lensing
    • Comets
  • Added 54 new concepts.
  • Deprecated 7 concepts.
  • The preferred label of 18 concepts were updated to add context, clarity, and consistency.
  • Added or updated AltLabels for 51 concepts, remove AltLabels for 4 concepts.
  • Added 1 definition and 4 scope notes.
  • Added 52 new related links, removed 8 related links.
  • Resolves Issues in Milestone Colrada.

The UAT is available for download on GitHub. For a detailed list of changes, see the full release notes.

Version 3.0.0 is available now!

Version 3.0.0 of the Unified Astronomy Thesaurus

The latest version of the UAT has been released!  Version 3.0.0 brings many changes and updates to the Unified Astronomy Thesaurus.

We heavily reworked the “Stellar astronomy” and “Solar physics” branches to reflect feedback from the community.  The organizational structure of the “Stellar types” section has proved challenging since the beginning of this project.  There are now multiple ways of approaching and organizing the stars, which reflect the myriad ways astronomers think about the topic.  Nearly 40 concepts were added to the “Solar physics” section, which was also renamed from “Solar astronomy.”  Besides adding concepts that describe new topics, we updated many concepts to differentiate between the Sun and the stars more generally.

Another branch that received heavy revision is “Computational astronomy”, as it holds the new sections on “Astronomy software,” “Computational methods,” and “Astronomy data analysis.”  Similarly, we added a new branch in the UAT for “Astrostatistics,” which covers common tools and techniques in that field.  We added these branches to reflect the importance of software, programming, and computational resources in modern day astronomy.

The last major addition to this version of the UAT comes in the “Laboratory astrophysics” branch, which deals with the study of atoms, molecules, plasmas, particles, dust, and ice in the lab.  Research conducted in the lab and theories about these fundamental topics inform astronomers and help them to understand the physical processes that they observer throughout the universe.

We also made many smaller updates and changes, in total adding 258 new concepts to the UAT.  242 new “related concept” links were added throughout the UAT, many of which increased the connections between solar and stellar concepts, and between concepts about the Milky Way galaxy and concepts about other galaxies.  Many specific stellar classes (i.e. T Tauri stars, or ZZ Ceti stars) were re-evaluated and moved to more relevant subsections of the UAT.  Many duplicate concepts were identified and merged.  We made updates and additions to the Alternate labels for over 190 concepts to help increase findability, as well as adding 15 scope notes and 8 definitions to increase clarity.  Finally, we deprecated 51 concepts, mostly due to duplication or low usage in the literature, streamlining sections of the UAT.

The UAT Steering Committee would like to thank the many people who reviewed and contributed the feedback, including Jason Barnes (University of Idaho), Nancy Brickhouse (Harvard-Smithsonian Center for Astrophysics), Adam Burgasser (UC San Diego), Ed DeLuca (Harvard-Smithsonian Center for Astrophysics), Eric Feigelson (AAS Editor, Penn State University), Leon Golub (AAS Editor, Harvard-Smithsonian Center for Astrophysics), Iouli Gordon (Harvard-Smithsonian Center for Astrophysics), Chris Lintott (AAS Editor, University of Oxford), Aimee Norton (AAS Editor, Stanford University), Jenny Novacescu (Space Telescope Science Institute), Radek Poleski (Ohio State University), Thomas Robitaille (AAS Editor, Astropy), Daniel Savin (AAS Editor, Columbia University), Sarah Weissman (Space Telescope Science Institute), and Henry “Trae” Winter (Harvard-Smithsonian Center for Astrophysics), among many others.

The UAT Steering Committee would also like to thank Kelsey Gibson, Katie Jones, and Jaihyun Park for their work building crosswalks between previous thesauri efforts and the UAT.


Unified Astronomy Thesaurus v.3.0.0 Release Notes Summary

Version 3.0.0 of the Unified Astronomy Thesaurus consists of a polyhierarchy with 2050 concepts, 11 top concepts, a depth of 11 levels, with 534 related concept links.

Release Date: 9/21/2018

Overview of Changes

  • Added 3 new branches:
    • Astrostatistics
    • Laboratory astrophysics
    • Astronomy software
  • Major revisions of various branches:
    • Stellar astronomy
    • Solar physics
    • Computational astronomy
  • 258 new concepts were added to the UAT.
  • 51 concepts were deprecated.
  • The preferred label of 88 concepts were updated to add context, clarity, and consistency.
  • Added or updated AltLabels for 196 concepts, remove AltLabels for 34 concepts.
  • Added 8 definitions, 15 scope notes, and 1 example.
  • Removed 20 related links, added 242 new related links.
  • Resolves Issues in Milestone Baerlon, Milestone Stellar types reorganization, and Milestone Solar physics updates.

The UAT is available for download on GitHub.
For a detailed list of changes, see the full release notes.


Recently Published Articles

Frey, K.; Accomazzi, A. The Unified Astronomy Thesaurus: Semantic Metadata for Astronomy and Astrophysics. 2018 ApJS 236 24.

Frey,K; Weissman, S.; Kern, B.; Lagerstrom, J.; Peek, J; Accomazzi, A. Managing Contributions to the Unified Astronomy Thesaurus. EPJ Web Conf., 186 (2018) 09003.


The UAT is an open source project supported by the AAS.

Version 2.0.0 of the Unified Astronomy Thesaurus

Today we are releasing Version 2.0.0 of the Unified Astronomy Thesaurus. This release cleans up minor errors, such as duplicate concepts and preferred label consistency. We have also changed all concept IDs to numeric identifiers, a change that will facilitate editing and management of the UAT going forward.

Overview of Changes

  • The UAT was switched from descriptive, human readable concept identifiers to numeric identifiers. This is a rather significant change, and included in the source code download for this version is a mapping from previous identifiers to new identifiers.
  • The preferred label of 79 concepts were updated to add context, clarity, and consistency.
  • 16 new concepts were added to the UAT.
  • 3 concepts were moved from one parent concept to another.
  • 9 concepts were merged into similar concepts to remove duplicates from the UAT.
  • Resolves Issues in GitHub Milestone Arinelle.

For a detailed list of changes, please see the release notes.

Unified Astronomy Thesaurus v.1 is here!

Today I am releasing version one of the Unified Astronomy Thesaurus (UAT v.1).

The UAT has been completely overhauled; restructured into new top level categories and re-organized throughout.  There have been many major revisions to bring it more inline with the way astronomers and astrophysicists study the universe.

I want to thank Sarah Weissman, Josh Peek, Kayleigh Bohemier, Dianne Dietrich, Jane Holmquist, Barbara Kern, and especially Jill Lagerstrom for all of the work each of you put into revising and updating the thesaurus.  I also want to thank the many researches and scientists who lent their expertise to this project.  Because of all of you, every term in the UAT was looked at, revised, edited, tweaked, or moved.

Version 1 of the Unified Astronomy Thesaurus has 1834 terms, 11 top level categories, a depth of 10 terms, and 319 ‘related term’ links.  For comparison, the beta version of the UAT had 1920 terms, 15 top level categories, a depth of 15 terms, and 224 ‘related term’ links.

In addition to the major restructuring of the UATs top level categories and overall organizational structure, 321 terms were removed, 236 new terms were added, and 95 new ‘related term’ links were added.

All thesaurus views on this website have been updated to UAT v.1.  The beta version can still be accessed via the archived files on GitHub and through the UAT Explorer (choose “beta” from the version drop down menu).

Of course, the work on this project is not finished!  The goal, in fact, is that it will never been finished.  There are still areas in the UAT that could be further improved and new terms that could be added.  We’re always interested in feedback on the UAT, and we have some long term ideas for an expansion that I am very excited about.

In the meantime, I will be presenting the Unified Astronomy Thesaurus at the upcoming AAS meeting in Kissimmie, FL on Wednesday January 6th and 12noon.  Hope to see you there!