| name | ads |
| description | Full ADS query syntax reference and search strategy for the ads_search, ads_paper, ads_citations, and ads_download_pdf tools. Load this before composing ADS queries — the tool descriptions only cover basic field prefixes. Contains: fielded search syntax, date/class filters (entdate, arxiv_class), citation operators, wildcards, positional search, properties, doctypes, daily arXiv listing patterns, and query recipes. |
ADS Query Syntax & Search Strategy
Reference: https://ui.adsabs.harvard.edu/help/search/
Query Basics
- Space = AND,
OR, NOT / - (exclude), () group, "phrase"
- Precedence:
NOT > AND > OR > implicit-AND > -
Fielded Search
Text Fields
| Field | Syntax |
|---|
| Title+Abstract+Keywords | abs:"phrase" |
| Title only | title:"phrase" |
| Abstract only | abstract:"phrase" |
| Keywords | keyword:"phrase" |
| Full text (body+abs+title+ack+kw) | full:"phrase" |
| Body only | body:"phrase" |
| Acknowledgements | ack:"phrase" |
Author
| Syntax | Meaning |
|---|
author:"Last, F" | Greedy match (initials, variations) |
author:"Last, First M" | More precise (recommended) |
author:"^Last, F" | First-author only |
=author:"Last, F" | Exact match, no synonym expansion |
Precision: author:"murray, s" (broadest) → "murray, stephen" → "murray, stephen s" (tightest)
Identifiers & Publication
bibcode:ID, doi:DOI, arXiv:ID, identifier:ID, bibstem:ApJ, volume:N, issue:N, page:N, year:YYYY or year:YYYY-YYYY, pubdate:[YYYY-MM TO YYYY-MM]
Affiliation
aff:"phrase" (raw), inst:"Harvard U" (curated, matches variants), inst:"UCLA/IGPP" (department), aff_id:ID
Object & Position
object:Andromeda (SIMBAD+NED), object:"(SMC OR LMC) AND M31" (combined), cone search: object:"RA Dec:radius" (decimal deg or sexagesimal, default 2', max 60')
Classification & Counts
database:astronomy|physics|general, doctype:type, arxiv_class:"class", property:flag, bibgroup:name, citation_count:[10 TO 100], author_count:[10 TO 100], read_count:N, facility:/regex/, orcid:ID, grant:agency
Synonyms & Case Sensitivity
- lowercase → matches variations + synonyms (e.g.
title:star → star, stars, stellar…)
- UPPERCASE → acronym-only (
title:STAR → only "STAR")
=field: prefix → exact match, no synonym expansion
Wildcards & Proximity
| Syntax | Meaning |
|---|
* / ? | Multi/single-char wildcard |
NEAR[N] | ≤N words apart, any order |
"term1 term2"~N | In-order proximity within N positions |
/regex/ | Lucene regex on indexed tokens |
Positional Search — pos(query, positions...)
Works on: author, aff, title. Examples: pos(author:"Oort, J", 2) (2nd author), pos(author:"Oort", 1,3) (1st–3rd), pos(author:"Oort", -1) (last), pos(aff:"harvard", 1) (1st author at Harvard)
Citation & Reference Operators
citations(query) = papers citing query results, references(query) = papers cited by query results. Nestable with other terms.
Second-Order Operators
similar(query) (textually similar), trending(query) (read by same readers), useful(query) (frequently cited by results), reviews(query) (citing papers ranked by freq), topn(N, query, sort)
Tip: similar() excludes originals; use disjoint entdate ranges to control overlap.
Properties
refereed, notrefereed, article, nonarticle, openaccess, ads_openaccess, pub_openaccess, eprint_openaccess, author_openaccess, data, esource, inspire, toc
Document Types
article, eprint, inproceedings, inbook, abstract, book, bookreview, catalog, circular, erratum, mastersthesis, newsletter, obituary, phdthesis, pressrelease, proceedings, proposal, software, talk, techreport, misc
Bibliographic Groups
Institutional: ARI, CfA, CFHT, Leiden, USNO | Telescope: ALMA, CXC, ESO, Gemini, Herschel, HST, ISO, IUE, JCMT, Keck, Magellan, NOIRLab, NRAO, ROSAT, SDO, SMA, Spitzer, Subaru, Swift, UKIRT, XMM
Daily arXiv Listings
Use entdate (day-resolution) with doctype:eprint and arxiv_class. Note: pubdate is month-resolution only.
# Today's astro-ph.CO (±2 day window)
arxiv_class:"astro-ph.CO" entdate:[2026-04-07 TO 2026-04-09] doctype:eprint
# All astro-ph classes
arxiv_class:("astro-ph.CO" OR "astro-ph.GA" OR "astro-ph.HE" OR "astro-ph.IM" OR "astro-ph.EP" OR "astro-ph.SR") entdate:[2026-04-07 TO 2026-04-09] doctype:eprint
Subclasses: CO (Cosmology), EP (Earth & Planetary), GA (Galaxy Astrophysics), HE (High Energy), IM (Instrumentation), SR (Solar & Stellar).
Search Strategy: Simplicity First
- Start with 2–3 core nouns. If too many results, add constraints (year, author, title:). Don't start with a sentence.
- ADS is keyword/metadata matching, not semantic search. Overloading queries kills recall.
- Use
detail='full' on fewer results rather than compact on many — abstracts often contain the answer.
Common Pitfalls
1. Compound multi-concept queries → zero results.
Fix: 1–2 core terms + sort_by + year_from:. Scan abstracts for specifics.
# Bad: "Population III He II helium 1640 JWST metal-poor galaxy candidate"
# Good: "Population III JWST" sort_by:date year_from:2024
2. Non-article doctypes polluting results.
Fix: doctype:article or property:refereed.
3. Iterative reformulation without simplifying.
If 2+ zero-result queries on the same topic: strip to 1–2 broadest terms, or use web_search first to find titles/authors, then look up in ADS.
4. Use web_search → ADS as a two-step pipeline.
For complex/emerging topics, start with web_search (plural queries, 2–4 varied angles) to identify key papers/arXiv IDs, then verify via ads_paper or targeted ads_search.
When Keyword Search Fails, Use Citation Networks
For interdisciplinary connections, find a known paper then walk citations (ads_citations) or references. Citation chains beat keyword matching for cross-domain discovery.
Quick Query Recipes
# Recent refereed articles on a topic
abs:"dark energy" year:2023-2025 property:refereed doctype:article
# Papers by first author at an institution
author:"^smith, john" inst:"MIT"
# Highly-cited reviews
reviews("machine learning astronomy") property:refereed
# Papers citing a specific work, sorted by citations
citations(bibcode:2023ApJ...950L..12A) sort:citation_count
# Object in specific journal
object:Andromeda bibstem:ApJ
# Open access with data links
property:openaccess property:data keyword:"gravitational waves"
# Exclude preprints, keep only journal articles
abs:"transiting exoplanet" doctype:article -arxiv_class:*
# Cone search
object:"12h30m49.4s +12d29m40s:5"
