Pointings Search

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Pointings FAQ

What is a pointings search?
Example of a search on a single or primary mission
Pointing and Band Definitions for Each Instrument

What is a pointings search?

The MAST "pointings" interface allows a user to search for ACS, WFPC2, STIS, FOC and NICMOS images 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 N times or more, 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. An exposure is defined to be the file created after the shutter closes. The total number of exposures for each of the defined bands within a defined pointing were tallied.

The definition of a pointing is different for each instrument. See the Search Help page for a more complete description of the methodology used to define a pointing.

Example of a WFPC2 Pointings search

An example of the type of query these tables will allow is: How many high galactic latitude observations taken with WFPC2 exist [for RA between 9 - 18 hours in the northern hemisphere (dec > -20) observable from the northern hemisphere in the early spring] where there have 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?

Choose the following options:

Galactic Latitude Above & below plane +/- > 20.0 degrees
Exposures in Band I >0
Number of Unique Bands >1
Total Number of Exposures >1
RA 09..18
Dec >-20.0

How are the pointings and bands defined for each instrument?

ACS 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

WFPC2 Definitions

All exposures within a 40 arcsecond radius are considered a pointing. Some exposures may fall within more than one pointing.

WFPC2 band definition
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

NICMOS 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

STIS Definitions

Instrument Configuration	Radius
MAMA	12.5"
CCD	26"

STIS 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 Definitions

FOC Radius Definition
Instrument Configuration	Radius
FOC/48	7"
FOC/96	7"

FOC band 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