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MAST currently provides many different types of services and searches, some of which have been implemented relatively recently. Look to see if the type of search you are interested in is listed below. If you cannot find the type of search you are looking for, please contact our help desk at

Service Description More Info
Cross Correlation Search or Quick Search
Search multiple missions using target name(s) or coordinates blueball
VizieR Catalog Search Search for Vizier Catalogs and then from the list of found catalogs, users may search a catalog and then cross correlate the found catalog entries with MAST missions selected by the user. blueball
The Scrapbook Lists and displays representative spectra or images from the MAST archive based on user-specified target name or coordinates. blueball
Mission Searches More advanced searches are possible for all MAST missions using dedicated search interfaces. blueball
High-Level Science Product Search Find High-Level Science Products (HLSP) fully processed (reduced, co-added, cosmic-ray cleaned etc.) images and spectra that are ready for scientific analysis, associated catalogs, atlases and readme files. The main HLSP information page also contains a search and list of HLSP. blueball
Search over all MAST missions by locally held catalogs. Search for sources belonging to a given list or class of astronomical objects. blueball
HST "Pointings" Search Search for sky regions observed with ACS, WFPC2, NICMOS, STIS images and FOC. You may also search the WFPC2 Assocations pointings. blueball
HST Parallel Search Search for HST Pure Parallels. blueball
HST Abstract Search
FUSE Abstract Search
IUE Abstract Search
EUVE Abstract Search
Search through HST, FUSE, IUE, or EUVE Abstracts for specific words or phrases. You may also search on words/phrases in the proposal titles, for primary investigator names and program id blueball
MAST Paper Links and Search
Dedicated ADS Search forms for HST and IUE
MAST provides direct links between archived data and published (refereed) papers based on those data. blueball

The Quick Search

The simplest, quickest way to search for data on a particular object or position is to use 'Quick Target Search.' This tool is available from our main page at To use it, the user either enters a target name, which is resolved by Simbad (the astronomical database of the Centre des Donnees astronomiques de Strasbourg) or by the NASA/IPAC Extragalactic Database (NED), or enters J2000 coordinates, where right ascension and declination are separated by a comma. The Quick Target Search returns a list of all relevant MAST datasets, including links to preview and dataset pages. By selecting 'Band/Data Type(s),' the user can restrict the search to specific wavelength bands. The output page summarizes the available datasets ordered by mission. For more output format options (e.g., csv, VOTable or excel spreadsheet files), or for entering multiple target names, use the cross correlation search form.

VizieR Catalog Search

Search for object catalogs in the VizieR database using catalog name, mission name, target name, wavelength range, and/or keywords. Users may then search within the catalog based on any object parameters contained in the catalog. The full catalog or the refined set of objects may then be cross-correlated with any MAST mission. Note that searches based on a large number of catalog entries and/or many HST instruments or MAST missions may result in query failures. In addition, users should be aware that searches may take several minutes, depending on the size of the request and bandwidth availability.

The Scrapbook

Using the spectral/imaging Scrapbook (, the user can delve deeper, to peruse selected (preview) spectra and images from most MAST missions (outside the Solar System). Using parameters like exposure times and observing date, we have chosen these observations as 'representative' of a named target or position on the sky. For spectra, we have selected the maximum exposure time and lowest dispersion for a given grating/wavelength configuration, which provides the broadest wavelength coverage. For images, we have chosen on the basis of exposure time, eliminating multiple pointings. In the Scrapbook, the results page provides links to preview and dataset pages, where the user can both learn what data are available and gain a multi-wavelength view of the source. Using an option available for the spectral Scrapbook, the user can co-plot representative preview spectra. After selecting them, the user clicks 'plot marked spectra,' which displays them all on a single plot of calibrated flux versus wavelength. The result is a single, broad-band spectrum, possibly combining the results of multiple instruments and missions. This tool is also available now to enable the overplotting of preview spectra from several, arbitrary datasets in a single operation, outside the Scrapbook. It can be used for any combination of targets from different missions - HST, IUE, FUSE, ORFEUS, WUPPE - to create a plot for an arbitrary selection of datasets. This tool is available at

The Mission Interfaces

Dedicated search interfaces permit advanced searches for all MAST missions. The user can access these interfaces from the individual mission pages or from By this route, the user can search for a particular object or a given position, specifying a variety of observational parameters, including exposure time, observing date, filters, and gratings. The result is a list of datasets matching the criteria, including various parameters, like target name, coordinates, instrument, and the number of published papers associated with the proposal ID (HST) or dataset name (other MAST missions). We are currently developing new features for the search interfaces.

The High-Level Science Product Interface

Dedicated search interface permits searches for High-Level Science Products (HLSP) hosted by MAST. The HLSP are fully processed (reduced, co-added, cosmic-ray cleaned etc.) images and spectra that are ready for scientific analysis. HLSP also include files such as object catalogs, spectral atlases, and README files describing a given set of data.

HLSP may be discovered in some mission search results pages. Look for the column labeled "High-Level Science Product" and click on the number to display a list of HLSP associated with the mission observation.

Searching on a list of targets or by class

We provide three options for archive users to determine which sources on a list or in a class of astronomical objects have MAST data. At, the user can upload a file containing a list of sky positions to cross-correlate with all MAST holdings. The result is a table with links to the MAST search pages for individual missions. More detailed multiple searches can be carried out from the individual search forms (e.g.,, where users can search on a list of sky positions or astronomical names. Finally, at, users can employ our catalog cross-correlation interfaces to correlate the MAST archive with the Hipparcos and Sky2000 star catalogs, an active galactic nuclei catalog, or the Abell catalog of clusters of galaxies. We plan to expand these class-search options.

The HST "Pointings" Search

To learn how many times an instrument has imaged a given region of the sky - with how many filters and when - the user can search ACS, WFPC2, STIS, NICMOS, and FOC exposures through the 'pointings' interface at This tool is useful for variability studies and serendipitous searches. It can provide answers to questions like, "How many and which WFPC2 pointings have more than two I-band exposures and two B-band exposures?" Or, "How many and which STIS pointings at low galactic latitude have observations separated in time by at least 100 days?" With the pointings interface, the user can search by position and by ranges in Galactic latitude, ecliptic latitude, right ascension, and declination. Future versions will allow multi-instrument searches, such as, "Which WFPC2 pointings have more than two U-band exposures and NICMOS data?"

The HST Parallel Search

Responding to the recommendations of the Cycle 7 Time Allocation Committee, we began the Archival Pure Parallel Program in June 1997, at the start of the Cycle 7 observations. This program continues. It seeks to maximize the scientific return from HST by taking parallel data with STIS, NICMOS, WFPC2 and now ACS whenever these instruments are not prime. The resulting data have no proprietary period and are promptly made available to the community. The Archival Pure Parallel Program strives to build large, consistent, and coherent datasets for the HST archive. Users can find more information at and access all pure parallel data at

The Abstract Search

Users interested in checking what science observations have been approved for HST can use the Abstracts Search at The user specifies search words or phrases in a syntax explained in the help section of the search interface. The search returns all matching proposal abstracts, information about the proposal, and - if the proposal has been executed - links to the archived data. You may also search the proposal abstract for FUSE, IUE and EUVE.

The MAST Data/Paper Links and Search Tool

MAST provides links between archived data and papers based on those data. These links work two ways. First, archive users can find the refereed papers based on MAST observations that were found in a mission-interface search. Clicking on the number in the 'Ref' column (which is the number of published papers associated with the found observations), the user can display the list of found papers, including title, first author, and journal reference (bibcode). The latter follows the Astrophysics Data System (ADS) bibliography code and is also a link to the ADS Abstract Service, which provides electronic access to the paper. Second, readers of on-line journals at the ADS can access the data when a paper is based on MAST holdings. At the end of 2001, MAST included links to almost 8,000 papers, of which more than 3,100 were based on HST data and almost 3,000 on IUE data. A list of MAST-based papers can also be searched at ADS, which now provides dedicated forms for HST and IUE papers. These forms are accessible at and The user can search on all the usual ADS fields, which include authors, object names, and abstract. Alternatively, the user can scroll down the ADS main page (, select "At least one of the following groups (OR)," and then select HST and/or IUE from the group list.