MAST Pointings Help
Help Index:
Introduction
Input Parameters
Output
Summary table
Pointings table
Exposures table
The MAST "Pointings" interface allows a user to search for ACS, WFPC2, NICMOS,
STIS and FOC exposures in a powerful way. For each of these instruments we have assembled a
searchable data table that allows users to look for sky regions (or pointings)
which have been observed more
than N times, observed with 2 or more filters, or have been observed
more than twice with a time separation of more than (or less than) N
days.
Included in each table are the total number of exposures
for a pointing and the number of unique bands.
The table also lists the date/time of first and last exposure for every
pointing.
An example of the kind of query this table will allow is:
How many high galactic latitude observations exist [for RA between
9 - 18 hours in the northern hemisphere (dec > -20)
observable from the northern hemisphere
in the early spring] where there has been at least two observations,
and where at least one of those observerations was in the I-band, and
at least one of those observations was in any other filter?
Galactic Latitude Above & below plane +/- > 20.0 degrees
Band I >0
Number of Unique Bands >1
Total Number of Exposures >1
RA 09..18
Dec >-20.0
Definition of a pointing
The definition of a "pointing" (unique set of sky coordinates) is slightly
different for each instrument configuration because the aperture size for each is
unique. The basic steps for the initial creation of a pointings table is the same for
all instruments. A list of unique candidate coordinates for a given instrument
configuration was created from the HST database. The software then
stepped through this list of coordinates. The first coordinate set was
by definition the first pointing assigned. All observations for that
instrument configuration that have center coordinates that fall within
the radius defined for that instrument configuration were marked as assigned
to a pointing. Subsequently, the software looked at each new candidate
coordinate set to see if the coordinate set fell within a previously defined
pointing. If the candidate pointing did not fall within a previously defined pointings
and there were unassigned observations that fell within half the
the radius for that instrument configuration, then it was assigned the next
pointing number. As a second step, the pointings were retained and the software
looks for all observations that fall within the pointings and counts the
number for each band, adds exposure times, and determines the first and last dates.
A pointings table is grouped by instrument, even though pointings for each specific configuration
are defined independently. For instance, the ACS pointings table contains pointings
for ACS/WFC, ACS/HRC and ACS/SBC observations, but the counts for a specific configuration include
only observations for observations taken with the same configuration.
Approximately once a week, the pointings tables for active instruments are updated.
For pointings that have already been defined, the counting process is repeated so that
new observations that fall within an existing pointings are included in the counts.
After that, the coordinates for any observations that are not assigned to an existing pointing
are used to determine new pointing definitions and the counts of bands, exposure times is
completed for those new pointings.
| The illustration below shows two observations that would be included as members of the same pointing. 
|
|
| The illustration below shows two observations that would NOT be included as members of the same pointing as the center of each observations is not within the defined radius of the image.  |
Tables that show assignment of filters to a "band" and lists the radius definition for a pointing for that instrument configuration are listed later in the file.
Filter choices for each Instrument/ Band.
ACS Radius and Band/Filter Definitions
| ACS Radius Definition |
|---|
Instrument Configuration | Radius |
| ACS/WFC | 101" |
| ACS/HRC | 13" |
| ACS/SBC | 15.5" |
| ACS/WFC band definition |
| B |
V |
R |
I |
z |
Line |
| F435W |
F555W |
F625W |
F814W |
F850LP |
F658N |
| F475W |
F606W |
|
F775W |
|
F502N |
| |
F550M |
|
|
|
F660N |
| ACS/HRC band definition |
| U |
B |
V |
R |
I |
z |
Line |
| F330W |
F435W |
F555W |
F625W |
F814W |
F850LP |
F892N |
| F250W |
F475W |
F606W |
|
F775W |
|
F502N |
| F220W |
|
F550M |
|
|
|
F660N |
ACS/SBC band definition |
| Far-UV |
| F115LP |
| F125LP |
| F140LP |
| F150LP |
| F165LP |
| F122M |
WFPC2 Band/Filter Definitions
| Filter choice for all bands |
| U |
B |
V |
R |
I |
Line |
| F300W |
F450W |
F606W |
F702W |
F814W |
F656N |
| F336W |
F439W |
F555W |
F675W |
F791W |
F673N |
| F255W |
F467M |
F569W |
F622W |
F785LP |
F502N |
| F380W |
F410M |
F547M |
|
|
F658N |
The WFPC2 "chevron" shape requires a smaller search radius to account for the pc chip.
The radius used to define a WFPC2 pointing is 40".
STIS (Image) Radius Band Definition
Instrument Configuration | Radius |
| MAMA | 12.5" |
| CCD | 26" |
| STIS (Image) band definition |
| Far-UV |
Near-UV |
Visible |
R |
Line |
Coronography |
| F25QTZ (FUV-MAMA) |
F25QTZ (NUV-MAMA) |
50CCD |
F28X50LP |
F28X50OII |
50CCDCORON |
| F25SRF2 (FUV-MAMA) |
F25SRF2 (NUV-MAMA) |
|
|
F28X50OIII |
|
| 25MAMA (FUV-MAMA) |
25MAMA (NUV-MAMA) |
|
|
|
|
FOC Radius and Band/Filter Definitions
| FOC Radius Definition |
Instrument Configuration | Radius |
| FOC/48 | 7" |
| FOC/96 | 7" |
| FOC bad definition for F/96 |
| Far-UV |
U |
B |
V |
Line |
Polarized |
| F220W |
F342W |
F430W |
F480LP |
F501N |
POL0;POL60;POL120;F342W |
| F140W |
F372M |
F410M |
F550M |
F486N |
|
| F175W |
F320W |
F437M |
F502M |
|
|
| F170M |
F275W |
|
|
|
|
|
| F130M |
F346M |
|
|
|
|
| FOC band definition for F/48 |
| Far-UV |
U |
B |
| F220W |
F275W |
F430W |
| F150W |
F342W |
|
NICMOS Radius and Band/Filter Definitions
| NICMOS Radius Definitions |
Instrument Configuration | Radius |
| NIC1 | 5.5" |
| NIC2 | 9.6" |
| NIC3 | 25.6" |
| NICMOS band definition for NIC1 |
| J |
H |
K |
Line |
| F110W |
F160W |
|
F187N |
| F110M |
F170M |
|
F095N |
| |
F165M |
|
F164N |
| NICMOS band definition for NIC2
|
| J |
H |
K |
Line |
| F110W |
F160W |
F222M |
F187N |
| |
F165M |
F205W |
F212N |
| |
F180M |
F237M |
F216N |
| |
F171M |
F207M |
|
| NICMOS band definition for NIC3 |
| J |
H |
K |
Line |
| F110W |
F160W |
F222M |
F187N |
| |
F150W |
F240M |
F108N |
| |
|
|
F212N |
This section describes the options available
- Coordinate Query Options
-
The first section of the search form contains the various
coordinate search options that may be included in the query.
Note that the RA/Dec range options may be combined with either
the galactic or ecliptic latitude options. Entering a target name
or specific coordinates for Target Name/Equatorial Coordinates
however, may not be combined with the other coordinate search options.
- Target Name/Equatorial Coordinates
-
Enter the name or the coordinates of the astronomical object of interest.
-
If you specify the name to be resolved for the "Coordinates"
or "Resolved Target Name" search, use
standard nomenclature as utilized by SIMBAD or NED for best results.
-
For the "Mission Target Name" search mode only, a "%" can be used as
a wildcard
and all names are converted to upper-case; e.g., entering "r136%" will
return all entries in which the mission object name begins with R136.
-
To specify coordinates, enter J2000 RA and DEC as decimal degrees or
as hours, minutes, and seconds. Several formats will be recognized
as coordinates:
- decimal degrees e.g. 65.4975 19.535 or 65.4975, +19.535
- hours minutes seconds e.g. 4 21 59.4, 19 32 6 or 4 21 59.4 19 32 6
- hours minutes, deg minutes e.g. 4 21 19 32 or 4 21, 19 32
- Name Resolver
-
Select either SIMBAD (the default) or NED for name resolution.
If the name is not found within either database, try entering
coordinates (J2000) instead of a target name.
This parameter applies only to the
"Target Name/Coordinates" search option.
- Search Radius
-
Enter the coordinate search radius in arcminutes. The default of
3 arcmin will work for many objects, but a smaller radius may be
needed in crowded fields. A larger radius may be needed to locate
a large extended object. This parameter applies only to the
"Target Name/Coordinates" search option.
- RA/DEC Range
-
Specify a start & end RA and/or DEC in decimal degrees (J2000) using
the "x .. y" syntax. For example, to search for all pointings between
10 and 30 degrees, enter: 10 .. 30 . Other possible conditions
include: <, >, <=, or >= .
- Galactic Latitude
- Search on galactic latitude.
- Above & Below Plane >: ± Search above or below the
galactic plane using designated latitude. e.g. entering 20 in >
box will result in search where galactic latitude > +20 and < -20.
- Within Plane < ± Search within the galactic plane the
galactic plane using designated latitude. e.g. entering 20 in the
box will result in search where galactic latitude < +20 and > -20.
- > Search where galactic latitude is greater than number entered:
e.g. entering 20 in the box will result in search where galactic latitude > 20
- < Search where galactic latitude is less than number entered:
e.g. entering 20 in the box will result in search where galactic latitude < 20.
- Ecliptic Latitude
- Search on ecliptic latitude.
- Above & Below Plane > ± Search above or below the
ecliptic plane using designated latitude. e.g. entering 20 in >
box will result in search where ecliptic latitude > +20 and < -20.
- Within Plane < ± Search within the ecliptic plane the
ecliptic plane using designated latitude. e.g. entering 20 in the
box will result in search where ecliptic latitude < +20 and > -20.
- > Search where ecliptic latitude is greater than number entered:
e.g. entering 20 in the box will result in search where ecliptic latitude > 20
- < Search where ecliptic latitude is less than number entered:
e.g. entering 20 in the box will result in search where ecliptic latitude < 20
- Band
- Specify specific bands for the search. If nothing is entered into
any bands, bands are not used for search criteria.
Specify if selection is to be on all bands chosen (and) or on
any of the bands chosen.
- And Select on all bands designated
- Or select on any bands chosen
For ACS searches (See table of filter choices for each band)
- U Enter the number of U band exposures required (e.g. 2, >=2, <10)
- B Enter the number of B band exposures required (e.g. 2, >=2, <10)
- V Enter the number of V band exposures required (e.g. 2, >=2, <10)
- R Enter the number of R band exposures required (e.g. 2, >=2, <10)
- I Enter the number of I band exposures required (e.g. 2, >=2, <10)
- z Enter the number of z band exposures required (e.g. 2, >=2, <10)
- Line Enter the number of Narrow band exposures required (e.g. 2, >=2, <10)
For WFPC2 searches (See table of filter choices for each band)
- U Enter the number of U band exposures required (e.g. 2, >=2, <10)
- B Enter the number of B band exposures required (e.g. 2, >=2, <10)
- V Enter the number of V band exposures required (e.g. 2, >=2, <10)
- R Enter the number of R band exposures required (e.g. 2, >=2, <10)
- I Enter the number of I band exposures required (e.g. 2, >=2, <10)
- Line Enter the number of Narrow band exposures required (e.g. 2, >=2, <10)
For NICMOS searches (See table of filter choices for each band)
- J Enter the number of J band exposures required (e.g. 2, >=2, <10)
- H Enter the number of H band exposures required (e.g. 2, >=2, <10)
- K Enter the number of K band exposures required (e.g. 2, >=2, <10)
- Line Enter the number of Narrow band exposures required (e.g. 2, >=2, <10)
For STIS searches (See table of filter choices for each band)
- FUV Enter the number of Far-UV band exposures required (e.g. 2, >=2, <10)
- NUV Enter the number of Near-UV band exposures required (e.g. 2, >=2, <10)
- V Enter the number of V band exposures required (e.g. 2, >=2, <10)
- R Enter the number of R band exposures required (e.g. 2, >=2, <10)
- Line Enter the number of Narrow band exposures required (e.g. 2, >=2, <10)
- Coron. Enter the number of Coronography exposures required (e.g. 2, >=2, <10)
For FOC searches (See table of filter choices for each band)
- FUV Enter the number of Far-UV band exposures required (e.g. 2, >=2, <10)
- U Enter the number of U band exposures required (e.g. 2, >=2, <10)
- B Enter the number of B band exposures required (e.g. 2, >=2, <10)
- V Enter the number of V band exposures required (e.g. 2, >=2, <10)
- Line Enter the number of Narrow band exposures required (e.g. 2, >=2, <10)
- Polar. Enter the number of Polarized exposures required (e.g. 2, >=2, <10)
The filter numbers in the table refer to wavelength in nanometers.
- Exposure Times
- Enter exposure limits (in seconds) for the total exposure
time in each desired band (e.g. >1000, or <10).
You may also specify if the search is to be for all specified
bands (and) or any of the specified bands (or). For example,
specifying "And" and entering >100 for "U" and >100
for "B" will return pointings for which the total exposure
times are > 100 seconds in the U filter and > 100 seconds
in the B filter. Specifying "Or" would return all pointings
for which the total exposure times are > 100 seconds in the
U filter or > 100 seconds in the B filter.
- Number of Unique Bands
- Enter a restriction for the number of unique filters.
- Number of Exposures
- Enter the number of for the total number of exposures e.g. <30
- Number of Days (numdays) between first and last exposure
- Enter the number of days required between the first and last exposure. Entering
>365 will look for pointings with exposures obtained at least a year apart.
- Submit Query
-
Click on this button to begin the query.
The Pointings Tables
will be searched for
entries which meet the specified search criteria.
The result may be none, one, or many objects. You may wish to
redo the search with a smaller search radius in a crowded field,
or using different search criteria.
- Reset
-
Clicking reset will return the form to its default values.
- Maximum Number of Pointings Displayed
-
The maximum number of rows (i.e., pointings) to be displayed on
the search results page. Allowed values are 10, 100, 500, 1000, and 5000.
The default is 100. Note displaying more rows will increase execution
time.
- Help
-
Clicking help will display this help file. If you still have trouble,
please e-mail your question to archive@stsci.edu.
The output of your query will include three parts:
- A summary section including a definition of the query
used to interrogate the database, and a
summary table containing the total number of pointings found,
the total number of unique exposures found, etc.
(See summary table heading descriptions below.)
- A table of pointing entries in which each row represents
one pointing matching the users search criteria. See description of
pointings table below.
- Links in the above two tables allow a third table to be displayed
which describes information about the individual exposures contained
in the selected pointing or pointings.
(See exposures table description below.)
This table summarizes the search results. Note that clicking on
the filter entries
in either the Summary table or the Pointings table will display the
individual exposures
described by the table entry.
The summary table column headings are described below.
- Mission/Instrument
-
The mission and/or instrument from which the data are derived.
The table entries will be linked to the appropriate MAST mission
home page.
- # of Pointings
- Total number of pointings found for a given
query, where a pointing is defined as a group of exposures
falling within a 40 arcsecond radius of one another.
- Exposures
- Total number of unique exposures for the
specified search criteria (i.e., exposures contained in
2 or more pointings are only counted once).
- FUV
- Total number of unique exposures/associations obtained
with a Far-UV band filter.
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "FUV" column of the pointings search results table).
- NUV
- Total number of unique exposures/associations obtained with a Near-UV band filter.
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "NUV" column of the pointings search results table).
- U
- Total number of unique exposures/associations obtained with a U band filter.
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "U" column of the pointings search results table).
- B
- Total number of unique exposures/associations obtained with a B band filter.
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "B" column of the pointings search results table).
- V
- Total number of unique exposures/associations obtained with a V band filter.
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "V" column of the pointings search results table).
- R
- Total number of unique exposures/associations obtained with a R band filter.
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "R" column of the pointings search results table).
- I
- Total number of unique exposures/associations obtained with a I band filter.
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "I" column of the pointings search results table).
- H
- Total number of unique exposures/associations obtained with a H band filter.
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "H" column of the pointings search results table).
- J
- Total number of unique exposures/associations obtained with a J band filter.
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "J" column of the pointings search results table).
- K
- Total number of unique exposures/associations obtained with a K band filter.
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "K" column of the pointings search results table).
- z
- Total number of unique exposures/associations obtained with a z band filter.
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "z" column of the pointings search results table).
- Line
- Total number of unique exposures/associations obtained with a Narrow band filter
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "Line" column of the pointings search results table).
- Coronography
- Total number of unique exposures/associations obtained
with a Coronograpy filter
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "Coronography" column of the pointings search results table).
- Polarized
- Total number of unique exposures/associations obtained
with a Polarized filter
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "Polarized" column of the pointings search results table).
- Other
- Total number of unique exposures/associations obtained
with any filter or filter
combination not explicity assigned to a band.
(note: since pointings may overlap, this number may be less than the sum of
the entries listed in the "Other" column of the pointings search results table).
- Exposure Display Format
-
Clicking on the filter totals in the summary table will run a script
to display the unique exposures for that particular filter and
selected search criteria. The default "retrieval list"
format will display data set names in an html table with options for
downloading files. The "print list" option displays a comma-separated
list of data set names which can be cut and pasted into other data
retrieval tools. The "file list" option writes the list of
data set names (one per line) to a file (dsn.txt) which can be
downloaded to the users computer.
- Maximum Number of Exposures Displayed
-
The maximum number of rows (i.e., exposures) to be displayed on
the exposure search results page. Allowed values are 50, 100, 500, 1000, and 5000.
The default is 100. Note displaying a large number of rows will increase execution
time and displaying a large number of buttons may cause some browsers problems.
Each row of the pointings table contains information on
the exposures within one pointing. The non-zero
"U", "B", "V", "R", "I", "H", "J", "K", "z", "LINE", or "OTHER" filter
entries contain two numbers: the total number of exposures/associations
obtained with a given filter (upper number),
and the sum of the exposure times for those exposures in seconds
(lower number). Clicking on the upper number
will display the exposures table (see below).
The pointings table column headings are described below.
- Mission/Instrument
-
The mission and/or instrument from which the data are derived.
The table entries will be linked to the appropriate MAST mission
home page.
- Pointing Number
- The number assigned to pointing.
- RA (2000), Dec (2000)
-
The right ascension and declination in J2000 epoch as
defined for a particular pointing.
-
Galatic Latitude and Longitude
-
The galactic latitude and longitude as
listed in the pointings table, as calculated from the J2000 ra and dec
in the mission catalog.
- Ecliptic Latitude and Longitude
-
The ecliptic latitude and longitude as
listed in the pointings table, as calculated from the J2000 ra and dec
in the mission catalog.
- Angular Separation
-
When performing equatorial coordinate searches, the angular separation
(radius), given in arcminutes, between the SIMBAD
(or NED) coordinates and the coordinates listed in the
pointings table.
- Total
-
Total number of exposures/associations counted for the pointing.
- U
-
Total number of exposures/associations obtained with "U band filters" counted for the pointing.
- FUV
-
Total number of exposures/associations obtained with "Far-UV band filters" counted for the pointing.
- NUV
-
Total number of exposures/associations obtained with "Near-UV band filters" counted for the pointing.
- B
-
Total number of exposures/associations obtained with "B band filters" counted for the pointing.
- V
-
Total number of exposures/associations obtained with "V band filters" counted for the pointing.
- R
-
Total number of exposures/associations obtained with "R band filters" counted for the pointing.
- I
-
Total number of exposures/associations obtained with "I band filters" counted for the pointing.
- H
-
Total number of exposures/associations obtained with "H band filters" counted for the pointing.
- J
-
Total number of exposures/associations obtained with "J band filters" counted for the pointing.
- K
-
Total number of exposures/associations obtained with "K band filters" counted for the pointing.
- z
-
Total number of exposures/associations obtained with "z band filters" counted for the pointing.
- Line
-
Total number of exposures/associations obtained with "Narrow band filters" counted for the pointing.
- Coronography
-
Total number of exposures obtained
with coronography filter or filter combination for this pointing.
- Polarized
-
Total number of exposures obtained with polarized filter or filter
combination for this pointing.
- Other
-
Total number of exposures/associations obtained with any other filter or filter combination
for this pointing.
- Unique
-
Total number of unique bands within this pointing.
- First Date
-
The observation date of the earliest exposure for this pointing.
For WFPC2 associations, the date of the earliest member of constituent
association-dataset for this pointing.
- Last Date
-
The observation date of the latest exposure for this pointing.
For WFPC2 association, the date of the latest member of any constituent
association-dataset for this pointing.
-
Xexp
-
Total exposure time for all observations in band X, where
X = U,B,V,R,I,Line,Other, ...
- Total Exposure
-
Total exposure time for all observations within pointing
This table lists the individual exposures or associations and data set
names or association IDs related to
the pointings in the pointings search results page.
Options on the search results page control both the page format
(i.e., html table or comma-separated list), and the maximum number
of entries displayed. The html table format allows the display of preview
images and data retrieval. Column headings are described below.
Row
The row number in the results.
Mark or Data Files
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.
Dataset Name
The unique identifier for an HST observation.
This value is hyperlinked. By clicking on it, you can display a preview
image of the observation.
Target
The name of the target of the observation, as given by the proposer.
PEP ID
The ID number of the observing program. Clicking
on an entry in this field will display the HST proposal search page
containing the proposal title, PI's name, abstract, ads links to published papers,
and a table of all known observations.
Occasionally, you will see target names like PAR, UNKNOWN-TARGET,
and so on; these are (most likely) parallel observations, which are observations done
by one instrument while another is making the primary observing of the telescope's visit.
RA
The equatorial right ascension of the instrument aperture, in equinox J2000.
(For the WFPC2, the aperture right ascension coincides with the V1 right ascension,
which is the middle of the field of view.)
Dec
The equatorial declination of the instrument aperture, in equinox J2000.
(For the WFPC2, the aperture declination coincides with the V1 declination,
which is the middle of the field of view.)
Preview Name
Name for preview file.
HLSP
Number of relevant High Level Science Products (HLSPs)
associated with given observation.
Galactic Latitude
Galactic Latitude for particular observation.
Galactic Longitude
Galactic Longitude for particular observation.
Ecliptic Latitude
Ecliptic Latitude for particular observation.
Ecliptic Longitude
Ecliptic Longitude for particular observation.
Association ID
Name of association (if any) for particular observation.
Band
Spectral band for particular observation (e.g., U,B,V,R,I,
Line, Other, ...)
Broad Category
Category of observation in a wide variety of designations (all uppercase).
Target Description
Target description in a wide variety of designations (all uppercase).
V3 Position Angle
The V3 position angle (PA_V3) is the direction in degrees east from
north that the tip of the L shape formed by
the 3 WF chips would point, if the L shape is imagined
to form the tip of an arrow. (see
WFPC2 Position & Orientation). The V3 position
angle is 180 degrees different (exactly opposite in direction)
rom the U3 position angle, which is specified by the observer
during the Phase 2 proposal process as the "ORIENT".
Exposure Time
The exposure time of the observation, in seconds.
For WFPC2 this is the sum of all exposures within that association.
Filter
The HST filter used for the observation.
For WFPC2 and FOC, this field contains the sci_spec_1234
field from the science table. For STIS, the sci_aper_1234
field is listed.
Detector
The HST Dector used for the observation.
This field contains the sci_instrument_config
field from the science table.
For NICMOS this will distinguish observations
using the NIC1, NIC2, and NIC3 cameras, and
for STIS, the CCD and MAMAs detectors.
For ACS this field will distinguish between the
WFC and HRC detectors. The SCS/SBC is not yet
included.
Observation Date
The starting date and time of the observation (GMT).
Release Date
HST data has a nominal proprietary period of one year
(though in special cases, this may be
shortened or extended).
The Release Date field gives the end of the dataset's proprietary period.
User Specified Field n
You may use these form elements to search on any column(s)
in the mission table. First, select the field
you wish to search from the pulldown menu under the "User-specified field n" heading.
Then, type in the qualification in the corresponding "Field Descriptions" box.
Clicking on the "Field Descriptions" link, will display information on the allowed fields
including the allowed range of values.
As an example, a Kepler user might select "E(B-V)" from the pulldown menu and
enter "< 0.5" in the "Field Descriptions" box.
NOTE only fields which are not already
included on the search form should be selected. Specifying search criteria
for a field that is listed in BOTH the form and in the User Specified field, may
cause either the query to fail or return unexpected results.
Output Columns
This form element allows you to choose the columns to be displayed
and their order, for the search results.
A set of columns that are commonly requested has been chosen as a default.
You remove output columns by highlighting the column to be removed and
then clicking on the remove button to the right of the output columns list.
You may determine the order of columns by highlighting a column and
then clicking the up or down buttons to the right of the list of
chosen output columns.
You may also add more columns to the list, either singly or all
at once. To add individual columns, select the desired
column from the pull down menu beneath the list of chosen output columns,
then click the add button. The column will be added to the bottom
of the output column list. To add all the available columns, click the
"add all" button.
Note the output column form element has its own reset button to restore
the list of output columns to the values initially displayed when the page
was drawn. The reset button at the top of the form is
used to reset the other form elements.
Clicking the "clear form" button will restore the original defaults to
all isections of the form.
One warning, the amount of memory required for a search is proportional
to the number of columns requested. For large requests, users may want to
reduce the number of output columns to the minimum required.
Suppress Null Result Message
By default, when using "file upload mode", the
message "No Records Found Matching Query" (or for non-html output,
"no rows found") is displayed
for each entry with no search results. Clicking this button
will prevent these messages from appearing which may be useful
for reducing output from large search results.
Verb
Verb is an integer parameter used by the VO community for specifying the
amount of output returned for a given search request. It is only
available when retrieving data as a web service but works with every
MAST service. Setting verb=3 in a search request is equivalent to
specifying "add all" from a search form;
it will return all the available columns in the output not just the standard
default fields. Currently setting verb to any other value has no effect.
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. Default sort fields
may be listed, but any field from the pulldown list can be used.
Specifying multiple sort fields may increase executon time.
If you prefer no sorting, you can specify "null" for all 3 fields.
This may speed up the query, but results will be displayed in
the order in which they were originally stored in the database table.
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.
One word of caution: the selected sort field can change the search results
when the query finds more rows than are displayed ( i.e, when the number of
found rows exceeds the value of "maximum records"). For example, for a search
on a particular coordinate that finds 5,000 entries, if the search
is sorted on exposure time
and 1,001 rows are to be displayed (the default), then the 1,001
shortest exposures
from the 5,000 found entries will be displayed
which may not include the entries closest to the
desired position. (It is a good idea to always sort on "ang_sep" for target or
coordinate searches).
Display Coordinates
Specifies the format for displaying the primary
equatorial (i.e., RA and Dec) coordinates. The options include:
- Sexagesimal - The default format with Right Ascension specified
as hh mm ss.sss and Declination as +/-dd mm ss.ss
( e.g., RA = 12 46 11.091, Dec = -00 30 12.08).
Note an extra digit was added as of June, 2012.
- Degrees - Decimal degrees for both RA and Dec with 7
significant figures to the right of the decimal point
(e.g., RA=191.5461912, Dec=-0.5033333).
Note 2 extra digits were added as of June, 2012.
or
- Hours - Decimal hours for RA and decimal degrees for Dec
in same format as for decimal degrees (e.g., RA=12.7697512, Dec=-0.5033333).
Note decimal hours = decimal degrees/15.0.
(Note 2 extra digits were added as of June, 2012.)
Any other coordinate fields contained in the searched mission catalog will be
displayed in their original format.
Maximum Records
This value specifies the maximum number of rows returned in a
single query. For the standard mission search forms, the current
default is 1,001, but values from 1 to 25,001 are allowed.
For the file upload forms in which multiple targets, data ID's, or
coordinates can be specified, the default is set to 20 rows per file entry,
with allowed values ranging from 1 to 5,000.
Note when displayed as HTML, the latest search scripts will display
100 records per page. Links to the additional pages are shown
on the results page.
This paging feature however does require javascript to be turned on.
Users should be cautioned about retrieving a large number of records
(i.e., > 10,000 - 15,000) in HTML format. This can cause memory
problems for the browser (particulrly Safari) and prevent javascript
commands from functioning. It may also cause the browser to freeze
and require restarting.
Using the output format options which download results in a file can reduce the
problem.
Another option for large requests is to use "Casjobs".
Casjobs requires requesting a user name and password, and submitting
queries in SQL, but it allows users to submit large search results and
save them online. For Kepler, the link ito Casjobs is
http://mastweb.stsci.edu/kplrcasjobs/.
For other missions, check the Search_Retrieve page in the left gutter.
When queries are submitted as a web service, the default number of rows
returned is 2,000, but any value is allowed when max_rows is specified
as a query parameter. (See the
MAST Web services page for more information.)
Records per page
This parameter controls the number of records displayed per web page.
By default, 100 rows or records are displayed per HTML page. Therefore if
400 records are returned, links to 4 pages will be displayed at the
top and bottom of the results table.
The paging feature however uses
javascript, so if javascript is turned off, paging won't work
and only the rows shown on the first page can be displayed. This is
one reason why increasing the default value may be helpful.
The current limit is 1000 rows per page which is recommended for large requests.
Note this value is ignored when output formats other than HTML are selected.
Make Rows Distinct
Selecting this checkbox will restrict the display to only rows in which
every output column value for a given row is unique. This option is primarily useful
when only a small number of columns are displayed (i.e., using the "remove"
button to remove default output columns) and when the selected columns
have duplicate values. Including columns which already have unique values (e.g.
Kepler ID or Data ID)
will make the "Distinct" option ineffective.
As an example, a IUE or FUSE user might want to create a list of unique target
names for a specific object class/category. He or she would specify the desired object
class, select only "object Class" and "target name" for the output columns,
click the "Make Rows Distinct" button, then click "Search".
Note that for some missions, columns such as RA, Dec and Magnitude were frequently defined
by the observer and often have different values for the same target.
If columns such as these are chosen as output columns, there will often
be more than one row listed per object name.
Output Format
You may choose any of the
following formats for displaying/storing search results.
If you are using a browser (e.g., Firefox, etc) to submit a query
from a MAST web form, the formats labelled "File: ..." offer a
way to download results directly to your local computer. Choose any of
the other format options if you want to display the results in the browser,
or if you are submitting the request from a program
(see MAST web services).
- HTML_Table (default) - results returned as a
standard HTML table including various links for retrieving data,
displaying previews, literature references, plotting spectra, etc.
- File: Excel_Spreadsheet - results are stored as an Excel
spreadsheet file.
(Note: assumes users computer/browser provides support for Excel-format files).
The default file name when downloaded is "mission"_search.xls where "mission"
is the mission name (e.g., fuse_search.xls).
- VOTable - an XML format adopted by the Virtual Observatory (VO)
project and displayed in the user's browser. Note coordinates in VOTable
format are always in decimal degrees rather than sexagesimal format.
For searches returning results from more than one mission and/or target,
multiple "resource" tags are created. Searches with a radius of 0
will return a VOTable file listing the output fields for that particular
mission/catalog. (For more information on the XML file format,
see VOTable documentation.)
- Comma-separated values - a simple ASCII array containing
column headings followed by rows of comma-separated values. In file upload mode,
a blank line is inserted between the search results to separate multiple target queries.
- Space-separated values - a simple ASCII array containing
column headings followed by rows of space-separated values.
In file upload mode,
a blank line is inserted between the search results to separate multiple target queries.
Note users may want to select
coordinates in decimal rather than sexagesimal format to maintain the
correspondence between column headings and entries although some column
headings may contain blanks as well.
(Semi-colons, pipes, or commas are probably safer delimiters.)
- IRAF Space-separated values with INDEFs - Like the space-separated format
above except empty fields are replaced with the string "INDEF". This format is useful
for IRAF-compatibility.
- Semi-colon separated values - a simple ASCII array containing
column headings followed by rows of semi-colon separated values. In file upload mode,
a blank line is inserted between the search results to separate multiple target queries.
- Tab-separated values - a simple ASCII array containing
tabs for delimiters. May be useful for ingesting into Excel spreadsheets.
- Pipe-separated values - a simple ASCII array containing
column headings followed by rows of pipe or vertical bar separated values.
(Note: not offered in file upload mode.)
- Json format - Javascript Object Notation (json) is a simple machine and
human-readable, name/value ASCII format supported by many programming languages.
(Note: not offered in file upload mode.)
- File: comma-separated values -
a simple ASCII text file containing
column headings followed by rows of comma-separated values. In file upload mode,
a blank line is inserted between the search results to separate multiple target queries.
Rather than being displayed in the browser, the results are directly downloaded
to the users computer using the file name "mission"_search.txt where "mission" is
the mission name (e.g., hst_search.txt). Depending on the
browser settings, the user may be prompted for a file location before the
file is downloaded.
- File: Space-separated values -
a simple ASCII text file containing
column headings followed by rows of space-separated values. In file upload mode,
a blank line is inserted between the search results to separate multiple target queries.
Rather than being displayed in the browser, the results are directly downloaded
to the users computer using the file name "mission"_search.txt where "mission" is
the mission name (e.g., hst_search.txt). Depending on the
browser settings, the user may be prompted for a file location before the
file is downloaded.
- File: IRAF Space-separated values with INDEFs -
Like the space-separated format
above except empty fields are replaced with the string "INDEF". This file format is useful
for IRAF-compatibility.
- File: Semicolon-separated values -
a simple ASCII text file containing
column headings followed by rows of semicolon-separated values. In file upload mode,
a blank line is inserted between the search results to separate multiple target queries.
Rather than being displayed in the browser, the results are directly downloaded
to the users computer using the file name "mission"_search.txt where "mission" is
the mission name (e.g., hst_search.txt). Depending on the
browser settings, the user may be prompted for a file location before the
file is downloaded.
- File: Tab-separated values - a simple ASCII file containing
tabs for delimiters. May be useful for ingesting into Excel spreadsheets.
- File: Pipe-separated values -
a simple ASCII text file containing
column headings followed by rows of pipe-separated values.
(Note: not offered in file upload mode.)
Rather than being displayed in the browser, the results are directly downloaded
to the users computer using the file name "mission"_search.txt where "mission" is
the mission name (e.g., hst_search.txt). Depending on the
browser settings, the user may be prompted for a file location before the
file is downloaded.
- File: Json format - Javascript Object Notation (json) is a
simple machine and
human-readable, name/value ASCII format supported by many programming languages.
Rather than being displayed in the browser, the results are directly downloaded
to the users computer using the file name "mission"_search.txt where "mission" is
the mission name (e.g., hst_search.txt). Depending on the
browser settings, the user may be prompted for a file location before the
file is downloaded.
- File: WGET Commands - This option is only available for
certain missions. If selected, a shell script file is
output which the user
can execute from his own computer to download all the selected light
curves or extracted spectral files with one command.
The shell script
file uses the "WGET" program which is available for most operating systems.
Note for Kepler, two WGET options are available:
"File: WGET LC commands" will create a script for downloading available light curves,
"File: WGET TPF commands" will create a script for downloading target pixel files.
For Swift, the WGET option will create a script for downloading
the Sky coordinate images.
Note: If no entries are found for an entry a
"no entries found" message is written in the selected format and
the program continues.
In all cases, error conditions will cause the database search to abort.