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Search Syntax

Search Basics

ADS’s one box search form supports both fielded and unfielded queries. Unfielded queries without search terms will search the metadata of the publications, including author, publication year, title, abstract, identifiers, and bibstem, which may not produce the expected results. For instance, if you are searching for papers by the author Marc Mars, you want to search for author:“Mars, Marc” instead of Marc Mars to make sure that you don’t return papers that simply have the words “Marc” and “Mars” somewhere in the article metadata.

Fielded Searches

Above the search box we supply shortcuts to frequently used search fields. Simply click on the field that you wish to search and enter your search term in the provided location (generally between the supplied quotation marks). Alternatively, if you start entering the name of a field an autocomplete feature will suggest a list of possible search fields. You may string several search terms or use the filters provided with your results to help narrow the search selection. For instance if you want to find articles published between 1980 and 1990 by John Huchra, you can use:

author:"Huchra, John" year:1980-1990

To get you started, here is a list of search examples for commonly used fields:

Example Query Explanation
author:“huchra, john” search for papers written by an author
author:“^huchra, john” limit search to first-author papers
^huchra, john limit search to first-author papers
abs:“dark energy” search for the phrase “dark energy” in abstract, title and keywords
year:2000 search for publications written in 2000
year:2000-2005 search for publications written between 2000 and 2005 (inclusive)
body:“gravitational waves” search for papers containing the phrase “gravitational waves” in the body of an article
full:“gravitational waves” search for papers containing the phrase “gravitational waves” in a number of fields (title, abstract, body, acknowledgements and keywords)
bibstem:ApJ select papers published in a particular publication
object:((SMC OR LMC) AND M31) using the SIMBAD and NED object search, find papers tagged with either SMC or LMC and M31

The rest of this page goes over the search syntax and fields indexed in our database.

Combining Search Terms to Make a Compound Query

You can string together any number of search terms to develop a query. By default search terms will be combined using AND as the default boolean operator, but this can be changed by explicitly specifying OR beween them. Similarly one can exclude a term by prepending a “-“ sign to it (or using the boolean “NOT”). Multiple search words or phrases may be grouped in a fielded query by enclosing them in parenthesis. Some examples:

Example Query Results
abstract:(QSO “dark energy”) papers containing both “QSO” and “dark energy” in their abstract
abstract:(QSO OR “dark energy”) papers containing either “QSO” or “dark energy in their abstract
author:“huchra, j” abstract:cfa papers by J. Huchra which have “cfa” in their abstract
author:“huchra, j” OR abstract:“great wall” papers by J. Huchra or which mention “great wall” in their abstract
author:“huchra, j” -title:2mass papers by “J. Huchra” but excludes ones with “2mass” in their title
author:“huchra, j” NOT title:2mass same as above
author:“accomazzi, a.” author:“kurtz, m.” papers authored by both A. Accomazzi and M. Kurtz
author:(“accomazzi, a.” “kurtz, m.”) same as above

Operator precedence in multi-part searches

Searches involving only two search terms, as shown above, are straightforward to parse. However, for searches with multiple search terms and multiple operators, understanding how operators take precendence over each other is important. For the most control, use parentheses around terms and operators that should be executed first. Otherwise, operators follow these general rules:

  • AND, OR, and NOT are set operators, operating on the search terms on either side. AND takes the intersection of the result set of the two search terms, OR takes the union, and NOT takes the difference. NOT takes precendence over AND, which takes precendence over OR.
  • The default AND (i.e., not typing out AND but using just a blank space between the two terms, as in the first example above) has lower precedence than any of the Boolean operators above.
  • The negative sign (-) is read as “prohibit”; results containing this term are completely excluded. In multi-part queries, its behavior can differ from that of NOT, because of the precedence rules.
Example Query Parsed as
aff:(China OR “Hong Kong” AND Taiwan) aff:(China OR (“Hong Kong” AND Taiwan))
aff:(China OR “Hong Kong” Taiwan) aff:((China OR “Hong Kong”) AND Taiwan)
aff:(China OR “Hong Kong” NOT Taiwan) aff:(China OR (“Hong Kong” NOT Taiwan))
aff:(China OR “Hong Kong” -Taiwan) aff:((China OR “Hong Kong”) NOT Taiwan)

For a more heavy handed exploration of the search syntax, feel free to visit the search parser details page.

Example Query Explanation
author:“huchra, jo*” multi-character wildcard; search for papers written by huchra, john, huchra, jonathan, huchra, jolie, and anything in between
author:“bol?,” single-character wildcard; in this case we may get back bolt, boln, bolm
title:(map NEAR5 planar) instead of a phrase search, we can ask the search engine to consider words be close to each other – the maximum allowed distance is 5; the operator must be written as NEAR[number]; in this example the search terms can appear in any order but there will be at most 5 other terms between (not counting stopwords such as a, the, in…). The proximity search must be used only against fielded search, i.e. inside one index. You cannot use proximity search to find an author name next to a title. If you are looking for token that appear next to each other, then please use a phrase search. For fields that are not tokenized (such as author names) use semicolon as a separator, e.g. author:"kurtz, m; accomazzi, a" OR author:"accomazzi, a; kurtz, m" – in a phrase search the order is important, so we much try both variants.
facility:/magell.*/ Regular expression searches are possible but are less useful than you might expect. Firstly, the regex can match only against indexed tokens - i.e. it is not possible to search for multiple words next to each other. So in practice, this type of search is more useful for fields that contain string tokens (as opposed to text tokens). In practice, this means that a field which contains many words (such as title, abstract, body) is a text field, but a field with only limited number of values is typically defined as a string - for example, author, facility, page. You can use regex in both string and text fields but you have to be aware that regular expression is only going to match indexed tokens. In the case of string fields tokens may be multi-word combinations, depending on the specific field. For example, in the author field one token is huchra, john, but in fulltext the same content will be indexed as two tokens: huchra, john. In all cases the tokens are normalized (typically by lowercasing the input data). A little bit or more of experimentation (test queries) should be enough to help you determine your ‘adversary’. For description of allowed regex patterns, please see: Lucene documentation

Synonyms and Acronyms

By default most search terms in ADS are expanded by adding a list of words which are synonyms of the search term. So for example, a search of “star” in the title field will be expanded to include words such as “stars,” “stellar,” “starry,” “starlike,” and so on. (Notice that this often includes words in foreign languages such as “etoile,” “stern,” and “stella”). While this feature improves recall, it sometimes compromises the precision of the results. Our search engine allows one to turn off the synonym expansion feature by simply prepending an “=” sign in front of the search term.

Our search engine also identifies acronyms during indexing and searching (defined as words consisting entirely of uppercase characters). A search for an uppercase word will only match documents which contain that acronym, whereas a search for a lowercase word will match documents which contain any variation of the word, irregardless of its case. Acronyms can themselves have synonyms (for example “ADS” and “Astrophysics Data System” are synonyms), so one should be aware that there is an interaction between case-sensitiveness and synonym expansion. The examples below illustrate these effects:

Example Query Results
title:star title contains “star”, any of its synonyms, or the acronym “STAR”
title:etoile title contains “star” or any of its synonyms (etoile being a synonym of star);
the results differ from above since “STAR” is not searched for
=title:star title contains “star” or the acronym “STAR”
=title:etoile title contains “etoile”
title:STAR title contains the acronym “STAR”
title:(=star -STAR) title contains “star” but not the acronym “STAR”
fuse the word “fuse” or acronym “FUSE” appear anywhere in the paper
FUSE the acronym “FUSE” appears anywhere in paper

Author Searches

Synoym expansion also applies to author names, which provide a way to account for changes in a person’s name and/or different spellings due to transliterations. In addition to this, the default author search in ADS is “greedy” in the sense that it will return all documents in which an author signature may match the input search string. This allows, for instance, to have an author search for “Huchra, John” to return papers where the author name appears as “Huchra, John” or “Huchra, J.” By prepending the “=” character to the author search one can disable this feature (as well as any additional synonym expansion) and require an exact match on the author name. Some examples:

Example Query Results
author:"murray, s" Least precise variations: finds records authored by any of the following:
  • Murray, Stephen S.
  • Murray, Stephen
  • Murray, S. S.
  • Murray, S.
  • Murray, Stephen D.
  • Murray, S. D.
  • Murray, Sarah S.
  • Murray, Scott
  • ...
(any possible combination with last name "murray" and first name starting with S)
author:"murray, stephen" More precise variations: finds record authored by any of the following:
  • Murray, Stephen S.
  • Murray, Stephen
  • Murray, S. S.
  • Murray, S.
  • Murray, Stephen D.
  • Murray, S. D.
  • ...
(any possible variation of "Murray, Stephen" with or without middle name)
author:"murray, stephen s" Most precise variations: finds record authored by any of the following:
  • Murray, Stephen S.
  • Murray, Stephen
  • Murray, S. S.
  • Murray, S.
(any possible variation of "Murray, Stephen S" but no others)
=author:"murray, s" Matches only records authored by "Murray, S."
=author:"murray, stephen" Matches only records authored by "Murray, Stephen"
=author:"murray, stephen s" Matches only records authored by "Murray, Stephen S."

As a general rule we recommend to use the full name of the person for author searches since as can be seen above the matching rules in ADS are designed to find the maximal set of records consistent with the author specification given by the user. Rather than disabling the name-variation algorithm described above, we recommend performing refinement of search results via the user interface filters for author names as described in the “Filter your search” section.

The logic behind the author search is rather complicated, if you would like to learn more, visit the advanced author search page.

Affiliation Searches

Affiliations in ADS have been indexed in several different search fields, with the intention of allowing multiple use cases. We have currently assigned affiliation identifiers allowing for parent/child relationships, such as an academic department within a university. Note that a child may have multiple parents, but we restrict a child from having children of its own. The list of recognized institutions is available from our Canonical Affiliation repository on Github.

Example Query Results
aff:“UCLA” Searches the raw affiliation string, searchable word-by-word
inst:“UCLA” Searches the canonical institution name listed in our mapping of organizations to identifiers, which returns all variations of UCLA (e.g. UCLA; University of California, Los Angeles; University of California - Los Angeles)

For a breakdown to department level:

  • Use the “Institutions” filter in the left panel of search results
  • Use parent/child syntax as defined in our list of Canonical Affiliations linked above (e.g. inst:“UCLA/IGPP”)

Users are reminded that while affiliation information is largely complete for recent refereed literature, not all records contain an affiliation; therefore, searching by affiliation alone will inherently be incomplete. We strongly recommend combining affiliation searches with author searches for best results.

The query modifier object: in fielded searches allows users to search the literature for bibliographic records that have been tagged with astronomical objects by SIMBAD and NED, or for a specified position on the sky (“cone search”). The cone search also makes use of services offered by SIMBAD and NED.

Queries for astronomical objects via object: queries return publications that have been tagged with the canonical names for these objects. This tagging has been done by the SIMBAD and NED teams. Additionally, the object names (as specified in the query) are also used in an ADS query against abstracts, titles and keywords in the astronomy collection (with synonym replacement switched off). The result set is a combination of all these matches. Object queries that target just one service (e.g. SIMBAD) are not currently supported. The data facet can be used to filter the results set.

The syntax for cone searches is:

  object:"RA ±Dec:radius"

where RA and Dec are right ascention and declination J2000 positions, expressed in decimal degrees or in sexagesimal notation (hours minutes seconds and degrees arcmin and arcsec). The plus or minus sign before the declination is mandatory. The search radius may be given in arcmin, decimal or sexagesimal degrees (The default search radius is 2’, and the maximum is 60’). Examples:

  • A 10’ radius may be written as 0.1667 or 0 10
  • The following 3 notations are equivalent:
    1. 05h23m34.6s -69d45m22s
    2. 05 23 34.6 -69 45 22
    3. 80.894167 -69.756111

Searching for publications tagged with objects returned by the coordinates in the example above, with a search radius of 10’ is done as follows:

object:"05h23m34.6s -69d45m22s:0.1667"

The equivalent of (see 2007ASPC..382..495K)

is the search object:"16 +60:0.1", followed by exporting the results in the VOTable export format. Currently there is no equivalent of the ADS Classic URL shown above.

Available Fields

This is a list of fields currently recognized by the ADS search engine and the preferred search format - go to comprehensive list of fields if not saturated yet:

Field Name Syntax Example Notes
Abstract/Title/Keywords abs:“phrase” abs:“dark energy” search for word or phrase in abstract, title and keywords
Abstract abstract:“phrase” abstract:“dark energy” search for a word or phrase in an abstract only
Acknowledgements ack:“phrase” ack:“ADS” search for a word or phrase in the acknowledgements
Affiliation aff:“phrase” aff:“harvard” search for word or phrase in the raw, provided affiliation field
Affiliation ID aff_id:ID aff_id:A00211 search for an affiliation ID listed in the Canonical Affiliations list in the child column. This field will soon also accept 9-digit ROR ids.
Alternate Bibcode alternate_bibcode:adsbib alternate_bibcode:2003AJ….125..525J finds articles that used to (or still have) this bibcode
Alternate Title alternate_title:“phrase” alternate_title:“Gammablitz” search for a word or phrase in an articles title if they have more than one, in multiple languages
arXiv ID arXiv:arxivid arXiv:1108.0669 finds a specific record using its arXiv id
arXiv Class arxiv_class:arxivclass arxiv_class:“High Energy Physics - Experiment” finds all arXiv pre-prints in the class specified
Author author:“Last, F” author:“huchra, j” author name may include just lastname and initial
Author (cont.) author:“Last, First […]” author:“huchra, john p” an example of stricter author search (recommended)
Author count author_count:count author_count:40 find records that have a specific number of authors
Author count (cont.) author_count:[min_count TO max_count] author_count:[10 TO 100] find records that have a range of author counts
Bibcode bibcode:adsbib bibcode:2003AJ….125..525J finds a specific record using the ADS bibcode
Bibliographic groups bibgroup:name bibgroup:HST limit search to papers in HST bibliography (*)
Bibliographic stem bibstem:adsbibstem bibstem:ApJ find records that contain a specific bibstem in their bibcode
Body body:“phrase” body:“gravitational waves” search for a word or phrase in (only) the full text
Citation count citation_count:count citation_count:40 find records that have a specific number of citations
Citation count (cont.) citation_count:[min_count TO max_count] citation_count:[10 TO 100] find records that have a range of citation counts
Copyright copyright:copyright copyright:2012 search for articles with certain copyrights
Data links data:archive data:NED limit search to papers with data from NED (*)
Database database:DB database:astronomy limit search to either astronomy or physics or general
Date Range pubdate:[YYYY-MM TO YYYY-MM] pubdate:[2005-10 TO 2006-09] use fine-grained dates for publication range
Document type doctype:type doctype:catalog limit search to records corresponding to data catalogs (*)
DOI doi:DOI doi:10.1086/345794 finds a specific record using its digital object id
First Author ^Last, F
author:“^Last, F”
^huchra, j
author:“^huchra, j”
limit the search to first-author papers
Fulltext full:“phrase” full:“gravitational waves” search for word or phrase in fulltext, acknowledgements, abstract, title and keywords
Grant grant:grant grant:NASA finds papers with specific grants listed in them
Identifiers identifier:bibcode identifier:2003AJ….125..525J finds a paper using any of its identifiers, arXiv, bibcode, doi, etc.
Institution inst:“abbreviation” inst:“Harvard U” search the curated list of affiliations (e.g. STScI and “Space Telescope Science Institute” have been matched); the full list is in the Abbrev column in the Canonical Affiliations list
Issue issue:number issue:10 search for papers in a certain issue
Keywords keyword:“phrase” keyword:sun search publisher- or author-supplied keywords
Language lang:“language” lang:korean search for papers with a given language
Object object:“object” object:Andromeda search for papers tagged with a specific astronomical object (as shown here) or at or near a set of coordinates (see Astronomical Objects and Position Search above)
ORCiD iDs orcid:id orcid:0000-0000-0000-0000 search for papers that are associated with a specific ORCiD iD
ORCiD iDs from publishers orcid_pub:id orcid_pub:0000-0000-0000-0000 search for papers that are associated with a specific ORCiD iD specified by a Publisher
ORCiD iDs from known ADS users orcid_user:id orcid_id:0000-0000-0000-0000 search for papers that are associated with a specific ORCiD iD claimed by known ADS users
ORCiD iDs from uknknown ADS users orcid_other:id orcid_other:0000-0000-0000-0000 search for papers that are associated with a specific ORCiD iD claimed by unknown ADS users
Page page:number page:410 search for papers with a given page number
Publication bibstem:“abbrev” bibstem:ApJ limit search to a specific publication
Properties property:type property:openaccess limit search to article with specific attributes (*)
Read count read_count:count read_count:10 search for papers with a given number of reads
Title title:“phrase” title:“weak lensing” search for word or phrase in title field
VizieR keywords vizier:“phrase” vizier:“Optical” search for papers with a given set of VizieR keywords
Volume volume:volume volume:10 search for papers with a given volume
Year year:YYYY year:2000 require specific publication year
Year Range year:YYYY-YYYY year:2000-2005 require publication date range

(*) See below for details on these filters. In most cases, filtering of results based on these fields is available in the user interface.


The “properties” search field allows one to restrict the search results to papers which belong to a particular class. The allowed properties currently include:

Property flag Selection
ads_openaccess An OA version of article is available from ADS
article The record corresponds to a regular article
associated The record has associated articles available
author_openaccess An author-submitted OA version is available
data One or more data links are available, see data field
eprint_openaccess An OA version of article is available from a preprint server (e.g. arXiv)
esource An electronic source is available, see esource field
inspire A corresponding record is available in the INSPIRE database
library_catalog A corresponding record is available from a library catalog
nonarticle The record is not a regular article; applies to e.g. meeting abstracts, software, catalog descriptions, etc
notrefereed The record is not peer reviewed (refereed)
ocr_abstract The record’s abstract was generated from OCR (may contain typos or mistakes)
openaccess The record has at least one openaccess version available
presentation The record has one or more media presentations associated with it
pub_openaccess An OA version of article is available from publisher
refereed The record is peer reviewed (refereed)
toc The record has a Table Of Content (TOC) associated with it

Bibliographic Groups

The “bibgroup” search field allows restriction of the search results to one of the ADS bibliographic groups. These groups are curated by a number of librarians and archivists who maintain either institutional or “telescope” bibliographies on behalf of their projects. Here is a partial list. For more information on the criteria behind the curation of these groups, please see the link above.

The list of current Institutional bibgroups is: ARI, CfA, CFHT, Leiden, USNO

The list of current Telescope bibgroups is: ALMA, CXC, ESO, Gemini, Herschel, HST, ISO, IUE, JCMT, Keck, Magellan, NOAO, NRAO, ROSAT, SDO, SMA, Spitzer, Subaru, Swift, UKIRT, XMM

The “data” search field can be used to select papers which have data links associated to them. The list of archives which ADS links to can be seen under the “Data” filter selection. To generate a list of all records which have data links one can issue a simple wildcard query: data:* . Using the data search field allows one to focus on data-rich papers, for example:

data:(CXO OR XMM) AND data:HST

Finds multi-wavelength papers which have observations both in the X-ray spectrum (from Chandra or XMM) and in the optical (HST). Of course additional search terms can be used to further refine the selection criteria.

Document Type

Records in ADS are assigned a document type which is indexed in the “doctype” search field, the contents of which are an extension of the BibTeX entry types. Currently these are the document types indexed by ADS:

Document Type Resource associated with record
article journal article
eprint article preprinted in arXiv
inproceedings article appearing in a conference proceedings
inbook article appearing in a book
abstract meeting abstract
book book (monograph)
bookreview published book review
catalog data catalog (or other high-level data product)
circular printed or electronic circular
erratum erratum to a journal article
mastersthesis Masters thesis
newsletter printed or electronic newsletter
obituary obituary (article containing “obituary” in its title)
phdthesis PhD thesis
pressrelease press release
proceedings conference proceedings book
proposal observing or funding proposal
software software package
talk research talk given at a scholarly venue
techreport technical report
misc anything not found in the above list