MAST Pointings Help

Help Index:
Introduction
Input Parameters
Output
       Summary table
       Pointings table
       Exposures table

Introduction

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

Input Parameters

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.

Output

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.)

Summary Table

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.

Found Pointings Table

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.

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

Exposures Table

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.

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.

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.

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.