spacer link to MAST page spacer logo image spacer
 
link to STScI page


STScI’s Internet connections will be UNAVAILABLE Sunday, November 18, 2018 from 5:00 AM to 9:00 AM. We apologize for the inconvenience.

UIT Search Help

Use the UIT Search form to search the UIT Catalog by object name, position, observation date, filter, etc., and to specify the output format. You can then view preview data and mark data for retrieval using this interface.

Object Name
The name of the astronomical object you want to search for. Examples of valid names include AX-PER, NGC0185, MARS, and HD269810. (Note that no spaces are used in UIT target names.)

When you search on the object name in the database, case will be ignored. The object name will not be wildcarded at the front and back (that's so if you innocently enter IO, you don't match things like ORION). You can wildcard the object name using *, however (for example, *IO*). You can also enter a comma-separated list; for example, *JUP*,*SAT* would match object names containing either JUP or SAT.

Object Resolver
The name resolver will let you resolve an object name into its coordinates. This is useful particularly for searching for objects that may be known by different names. You can resolve an object name either before a search, or you can redraw the form with the resolved coordinates in place. If you don't elect to resolve the object name, the UIT database will be searched on the object name given.

The SIMBAD and NED object name resolvers can resolve only fixed objects; they cannot compute the positions of moving objects (planets, comets, etc.). To find moving objects, try selecting the appropriate object class, entering an object name that could match what you're looking for, and selecting Don't resolve for the name resolver. NED is an extragalactic database, and generally won't resolve object names within the Milky Way galaxy.

To resolve an object name before a search, enter the object name in the Object Name field, select either SIMBAD or NED for the resolver, and hit the Search button. (NED is the Nasa Extragalactic Database at Caltech in Pasadena, California, and SIMBAD is the Set of Identifications, Measurements, and Bibliography for Astronomical Data at the Centre de Données astronomiques in Strasbourg, France.) The object name will be sent to SIMBAD, which will send back the coordinates. (If the object name is not recognized by the resolver, or there is some other problem with the SIMBAD service, then the search form will be redrawn with an error message at the top.) These coordinates will then be used to search the UIT database, along with whatever other query qualifications you have given.

You can also hit the Resolve button instead of the Search button. In that case, the search form will be redrawn with the object's right ascension and declination entered as defaults in the RA and Dec fields. Resolving an object name will not change any other choices made in the form, except for the equinox, which will be reset to J2000 (since the SIMBAD resolver returns J2000 coordinates).

We recommend that you use object name resolution to find observations of specific objects in the database. This is the most reliable way to look up observations, because the observer could have given any object name at all (for example, NGC1976 instead of M42). However, if you do know the object name that the observer used, you can select Don't resolve, in which case the object name will not be resolved into coordinates, but will be used as a search qualification in the database. (This will happen only when you press the Search button.)

Resolve
When you press this button and select SIMBAD for the resolver, the UIT Search form will be redrawn with the coordinates for the given object entered into the RA and Dec fields. If you then press Search, the search will be conducted on that position. (The resolver will not be re-run for the search, unless you change either the object name or the resolver).

The SIMBAD and NED object name resolvers can resolve only fixed objects; they cannot compute the positions of moving objects (planets, comets, etc.). To find moving objects, try selecting the appropriate object class, entering an object name that could match what you're looking for, and selecting Don't resolve for the name resolver. NED is an extragalactic database, and generally won't resolve object names within the Milky Way galaxy.

RA, Dec
The Right Ascension and Declination around which you want to search. These fields give the J2000 equatorial coordinates for the center of the image. A number of formats are accepted for the RA and Dec. Here are some examples:
    Decimal Degrees
       	185.63325 29.8959861111111
 
    Hours, minutes and Seconds
        12 22 31.98      29 53 45.55
        12h22m31.98s     29d53m45.55s
        12:22:31.98     +29:53:45.55
        12h22'31.98"     29d53'45.55"
        12h 22m 31.98s   29d 53m 45.55s
        12h 22' 31.98"   29d 53' 45.55"
        12h 22' 31.98"  -29d 53' 45.55"
        12h22'31".98    -29d53'45".55
        12h22m31s.98    -29o53m45s.55
        12h 22' 31".98  -29d 53' 45".55
     
    Hours/Degrees and Minutes (no seconds)
        12 22     29 53
        12h22m   +29d53m
        12h22m    29d53m
        12:22m    29:53m
        12h22'    29d53'
        12h 22m   29d 53m
        12h 22'   29d 53'
        12h 22'  -29d 53'

    The RA may be given in decimal degrees by 
    indicating a D or d after the degrees:
        12d 22m   29d 53m
Spacing is not important, as long as the value is unambiguous, and that you delimit the hours/degrees, minutes, and (optional) seconds with letters, colons, spaces, or any character that's not a digit or a decimal point.

Note also that seconds of the form 31".98 or 31s.98 are accepted. This should make it easy to cut and paste values into these fields from electronic publications.

Radius
The radius of the search box around the RA and Dec, in floating-point arcminutes (e.g., 5.0). You should be careful about giving too restrictive a search radius in an UIT search.

Equinox
The equinox of the RA and Dec you have entered, either B1950 or J2000. This affects only the input coordinates; there is a separate selector for the equinox of the output coordinates.

If you hit the Resolve button to get an object's coordinates and redraw the form, the equinox will be set to J2000, since that's the equinox of the coordinates returned by the object name resolvers.

Object Category
This is a broad category for the target. One or more values may be selected. Clicking "reset to defaults" or "clear form" (described below) will erase previous selections.

Observation Start Time
This is the GMT time, to the nearest second, of the start of the observation. (Note the UIT1 observations were all obtained during December 2-10, 1990, and UIT2 observations were obtained during March 2-18, 1995.)

When specifying this date, you need to include at least a date; a time is optional. The date can have any of the following formats (the month name can be spelled out or abbreviated to three letters; case is not significant):

      Dec 15 1990
      Dec 1990 15
      15 Dec 1990
      1990 Dec 15
      1990 15 Dec
      7/15/1990
      7-15-1990
      7.15.1990
    
If the day is omitted, the first day of the month is assumed. This means that a specification like "Dec 1990" will look for observations done on Dec 1 1990 00:00:00, not for observations done during December 1990. Note also that when entering a date with the month in numerical format, the American ordering is used; i.e., the first number is the month.

If a time is omitted, then any time for that day will match. Otherwise, you can specify a time in any of these formats:

      14:30
      14:30:20
      14:30:20:999
      14:30:20.9
      4am
      4 PM
      04:30:20 AM
    
To search for observations before a given date, use <, and for observations after a given date, use >. For example,
      > Dec 10 1990
      < Dec 10 1990
    
You can use the .. operator to search on a range of dates:
     Mar 2 1995 .. Mar 5 1995
   
This operator is inclusive on the first date and exclusive on the second.

Finally, you can search on a list of dates or date ranges. For example,

     Mar 10 1995 .. Mar 11 1995, 
     Mar 15 1995 .. Mar 16 1995
   
will search for observations done within either one of these date ranges.

Exposure Time
The exposure times annotated on the film by the Dedicated Experiment Processor (DEP) were found to be incorrect by known amounts. The corrected exposure times used in the batch data processing (BDR) are stored in the database and in the FITS headers using the keyword EXPTIME (uncorrected times are stored in the FITS header using the keyword FEXPTIME.)

The corrected exposure length was computed from

  • (a) the exposure time written onto film (if it had no hex digits) plus 0.5 seconds, or
  • (b) if the exposure time written onto film had hex digits (i.e., it was the first frame in the exposure sequence), then the value from the previous film frame was used after subtracting 0.3 seconds, or
  • (c) telemetry plus 0.5 seconds.
Null entries imply a raw density image was obtained. The uncertainty in the corrected exposure times for the majority of exposures is of the order of 0.04 seconds (Stecker et al, PASP 109,584 1997).

Data ID
The UIT Data ID uniquely defines each UIT observation. The name is of the form CuvMnnn where
  • C = "N" for the near-UV camera (which failed during the ASTRO-2 mission), or "F" for the far-UV camera,
  • M = "0" for ASTRO-1 data, "1" for ASTRO-2 data before a Dedicated Experiment Processor (DEP) memory change reset the frame counter, or "2" for ASTRO-2 data after the DEP memory change.
  • nnn = a three-digit number designating the order in which the UIT observations were obtained for a particular camera.
As an example, data ID FUV2349 designates the 349th exposure with the Far-UV camera during the ASTRO-2 mission.

Note that for each observation, several data sets may be produced representing different stages of processing. The final linearized, undistorted data set may be stored using a file name such as fuv2349g.fits.

Filter
The UIT instrument included two six-position filter wheels. The "A" filters were sensitive in the near-UV while the "B" filters were sensitive in the Far-UV. The near-UV camera was operational only for the ASTRO-1 flight. The effective wavelengths and FWHM's are listed on the Instrument page.

User Option
You may now search on any column in the mission database. Select the field you wish to search on and type in the qualification. You may find the valid range of values by clicking on the field name. NOTE that if you choose a field in BOTH the form and in the User Option field, then you may not get results or the result you expect.

Output Columns
Your choice of what columns you want to see in the output. There are two radio buttons that let you select either the default set of columns, or choose your own set of columns.

The default set of columns for raw data sets is (in the order displayed):

	  Mark
      Data ID
      Target Name
      RA (J2000)
      Dec (J2000)
      Filter
	  Reference
      Obs. Start Time
      Exp Time
      Category
      ang sep (')
    

You can select your own output columns by pressing the custom... radio button and selecting the columns from the list below it. The output columns will be in the order in which they appear in this list.

Sort output by:
Choose how you want the output rows sorted. You can select up to three fields to sort on. The rows will be sorted in the order of the first sort field; if two rows have the same sort field, they will be sorted in order of the second sort field, and so on.

For each field, you can select that the rows be sorted in reverse order on that field by selecting the reverse checkbox. For example, you can sort the rows with the most recent observations first by selecting Observation Date for the first sort field and selecting the reverse checkbox next to it.

Make Rows Distinct
Select this checkbox if you want to have a set of distinct rows displayed. This is useful if you would like to see a distinct list of objects with certain criteria e.g. all the objects within an object class. To make this function useful, you should not select column names such as Data Id, Mark or Observation Date in as output columns as all output is considered when making rows distinct. Note that columns such as RA, Dec and Magnitude were defined by the IUE GO and often have different values for the same target name. If columns such as these are chosen as output columns, there will often be more than one row listed per object name.

Maximum number of hits
Some queries will be capable of returning hundreds of rows or more. Such large search results tend to use up memory on both the client and server sides, and aren't usually useful. By default, we limit the number of rows displayed to 100 rows, but you can increase (or decrease) this limit as needed.

Output equinox
Just what you'd think: the equinox of the coordinates displayed in the output.

Show SQL Query
Select this checkbox if you want to see the SQL query that the UIT Search engine constructs from your query qualifications. The query will be shown at the end of the search results.

SQL (Standard Query Language, pronounced either "ess cue ell" or "sequel") is a language used by most relational database systems for retrieving information from database tables. The UIT Search Page takes your search specifications and converts them to an SQL query to run on our database. Viewing the generated query is often useful for debugging, and may also be useful for SQL-literate users who want to see what logic was used in the query. (In fact, this may be useful for most people, since SQL is pretty easy to understand.)

Display Options
You may choose one of three display options: HTML Form, a comma separated list, and Excel spreadsheet