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FUSE Search Results Help

This page describes the output columns on the FUSE Search Results page. For information about FUSE and its data, see the FUSE homepage at

Use the FUSE Science Search form to locate and retrieve observations from the FUSE data archive at STScI. Both public and proprietary data may be retrieved through this interface.

The FUSE Science Search form offers a view of FUSE observations, which comprise one or more exposures. To locate individual exposures, use the FUSE Exposures Search page. More information about retrieving FUSE data may be found on the FUSE retrieval help page.

General Results Options

Most mission search results pages have the following general features/options. (Note that the sorting, paging and VOPlot options all require JAVASCRIPT to be supported and turned on, and the interactive plotting option uses HTML5 which is not supported in Internet Explorer before version 9.)

  1. Clicking on the column headings at the TOP of the results table will sort the returned results based on the selected field. Clicking the column heading a second time will sort the results in descending order. As of August, 2014 sorting is now possible with RA and Dec coordinates in sexigesimal notation, and the previous bugs whereby exponents are ignored in numbers using exponential notation (e.g., 6.3E-3 is sorted as if it were 6.3), and signs were ignored in floating point numbers have both been corrected. Note however that the sort functions (like many interactive features) are written in javascript which is not always supported in older browsers. Alternatively, selecting the sort options in the initial query does not depend on javascript, and will sort the entire search result, not just the displayed rows.

  2. Clicking one of the column headings at the END of the results table (or clicking the "columns help" link at the top of the page) will display help information about the search results page and the displayed columns (i.e., this page).

  3. By default, results are shown with 500 entries per page, with links to additional pages if more than 500 entries were returned. The number of rows per page can be modified using the "Records per Page" form element on the search form. The total number of entries returned is set by the "Maximum Records" value from the search page.

  4. One numerical column can be plotted versus another using VOPlot although see the Help page regarding issues with the latest version of Java.

  5. For some missions, thumbnail images of the returned entries can be displayed by clicking the link listed just below the VOPlot link.

  6. The mark column, as described below, can be used to plot spectra and download files. Plots are now interactive with added features.

Column Information

Mark this dataset for retrieval by pressing this checkbox. After you have marked for retrieval all the datasets that you're interested in, hit the Retrieve Marked Datasets for Retrieval button to initiate the retrieval.

Proprietary datasets will have a @ character next to their mark buttons (and in some browsers will show up with a yellow background). Proprietary datasets can be marked and retrieved by appropriately authorized users. If you are a principal investigator and would like to retrieve your data (or would like to authorize one of your co-investigators to retrieve your data), contact us at

Users running Javascript-enabled browsers will see some buttons at the top and bottom of the search results labelled Mark all, Unmark all, etc. These buttons may be used to mark or unmark all of the datasets in the search results; mark or unmark only the proprietary datasets; or mark or unmark only the public datasets.

Target Name
Target name as stated in proposal.

The equatorial right ascension of the target, in equinox J2000.

The equatorial declination of the target, in equinox J2000.

Data ID
Name of an individual exposure within an observation set (i.e., same as FITS header keyword ROOTNAME) Also referred to as the Exposure ID on the exposure search form.

Observation Name
The Observation name is the unique identifier for a FUSE observation. (For FUSE, an observation is an association of exposures.) In the FUSE Observation search the Observation Name is the Data ID. This is the same as the association ID also.

Preview Name
The name of the FUSE Preview, where a preview exists. Where no preview exists the value is null. The preview name is the same as the Observation Name.

observation ID from proposal database

Association ID
Unique identifier assigned to association or observations.

target aperture (PINH, HIRS, MDRS, LWRS, RFPT)

  • LWRS (30"x30"; 100% throughput)
  • MDRS (4"x20"; 98% throughput)
  • HIRS (1.25"x20"; 85% throughput)
  • PINH (Pin hole - hasn't been used as of 9/24/2002)
  • RFPT Used either for instrumental test programs, or when long background observations are made. The latter are tagged with a target name, but since the target is at the reference point, its light is not entering the spectrograph through one of the science apertures.

The number of referred journal articles using this observation. Click on the number to see the list of articles.

Aper Pos Angle
position angle of y axis (deg. E of N)

bandwidth of the data (Angstroms)

Cent Wavelength
central wavelength of the observation (Angstroms)

Obs date
Date and time of start of observation

Color excess (B-V)
color excess E(B-V)

Ecl Lat
ecliptic latitude (deg)

Ecl Lon
ecliptic longitude (deg)

Gal Lat
galactic latitude (deg)

Gal Lon
galactic longitude (deg)

High PM
high proper motion target (T or F)

Moving Target?
[F]ixed or [M]oving target

object class (modified IUE classification).
Also called Object Class.

End Time
observation end time

Start Time
observation start time

Exposure Time
exposure duration (seconds)--calculated

Obs Stat
Science Data Processing observation status code(?)

PI First Name
First name of principal investigator.

PI Last Name
Last name of principal investigator.

observation ID from data header

Spectral Type
MK spectral type and luminosity class

Source Type
[P]oint, [E]xtended, [C]ontinuum, [E]mission line

Target Type
Not currently used.

Target ID
Target ID from data header

Telescope (Always FUSE).

V mag
target V magnitude

Min wave
minimum wavelength of the observation (Angstroms)

Max wave
maximum wavelength of the observation (Angstroms)

Radial Velocity
Radial Velocity (z value)

Archive Class
The DADS archive class (FUS for calibrated data, FEN for engineering data ).

Archive Date
The date the processed data was archived in DADS.

Generation Date
The date the processed data was generated.

Aper Act
actual target aperture (PINH, HIRS, MDRS, LWRS)

Det Mask
detector mask used

Exp End
exposure end time (as opposed to observation end time)

Exp Endc
condition that ended exposure (ENDO; SAA; OCC; NGHT; ENDE)

Exp Start
exposure start time (as opposed to observation start time)

Exp Time
exposure duration (seconds)--calculated (Note this is different from the "Exposure time" field which describes the total exposure time for the entire observation.)

Exp ID
exposure ID from data header

Exp Stat
Science Data Processing status (0=good)

binsize used for pixel binning in FES images (1;2;4;8)

FES Filt
FES filter wheel position (CLR=Clear, COL=color, ND=Neutral Density, DEF=)

FES Tpos
FES target position: IN or OUT

FPA1 LiF X position

FPA1 SiC X position

FPA2 LiF X position

FPA2 SiC X position

Number of FP split positions

Int Cal
internal calibration (STIM or NONE)

Roll offset (deg)


Spec Binx
Binsize in detector X coordinate for HIST mode

Spec Biny
Binsize in detector Y coordinate for HIST mode

target acquisition sequence

Program ID
program ID from data header. Values range from Annn to Znnn.

Total CR
Total count rate (counts/s)

TT Period
time marker insertion period for TTAG data

Instrument Mode
Instrument Mode

The FUSE instrument has a simple design with few observing modes. The correct mode of observing is generally derived from the Phase 2 proposal information (based on target flux and the desired S/N and spectral resolution) for event rates < 2500 counts/sec (corresponding to a flat spectrum source with flux of ~8 10-12 erg cm-2 sec-1 -1 in the LWRS aperture), TTAG mode is the default observing mode. For rates higher than this, spectral image (HIST) mode is used by default . For more information see the The FUSE Observer's Guide section on Observing Modes.

Release date
FUSE data has a nominal proprietary period of six months (though in special cases, this may be shortened or extended). The Release Date field gives the end of the dataset's proprietary period.

When the results of a search query are displayed, both public and proprietary datasets will have mark buttons. Proprietary datasets will have an at symbol, @, next to the mark button, and on most browsers, the background for proprietary mark buttons will be yellow. Properly authorized users will be able to retrieve proprietary data through the Web interface.