Step-by-Step APT Guide for MIRI and NIRCam Coronagraphy of HR8799 b

jdoxSectionImagenone

Instructions for filling out the MIRI and NIRCam Coronagraphic Imaging observing templates in the Astronomers Proposal Tool (APT) for the HR8799 b example science program are presented and discussed.

Example Science Program #36: APT Guide

Introduction

Main article: NIRCam and MIRI Coronagraphy of HR8799 b
See also: JWST Astronomers Proposal Tool Overview

The Astronomer's Proposal Tool (APT) is the official submission tool for all JWST proposals. Filling out a JWST proposal in the APT involves entering proposal information, specifying information about the target(s), setting up the observation(s), defining any special requirements, and ensuring the program can be scheduled as specified. This guide provides a walkthrough of this process for the "NIRCam and MIRI Coronagraphy of HR8799 b" Example Science Program. 

A filled out APT file can be accessed via the APT menu options File → Retrieve from STScI → Retrieve using Proposal ID, and then entering 36 in the dialogue box.

Fill out Proposal Information

Main Article: APT Proposal Information

The APT Proposal Information section provides a place to enter the proposal Title, Abstract, PI and CoI information, and other information of a supporting nature for your proposal. It can be found in the Tree Editor of APT and contains the information that will ultimately appear on the cover page of the formatted APT proposal. Opening the Proposal Information tab on the Tree Editor avails additional sub-sections, one for entering a program summary text block and an interface to enter PI and CoI information as appropriate. It also contains a place to add the name of the PDF file for uploading prior to submission of your proposal.


Enter Proposed Targets

Main article: APT Targets

The next step is to specify our proposed targets. Target information is entered by selecting Targets in the Tree Editor, which provides options in the Active GUI window.

Our program consists of three Fixed Targets: our science target HR 8799 (i.e., * HD 218396) and PSF reference stars HD 218261 (for NIRCam) and and HD 220657 (* ups Peg; for MIRI). Using the APT Fixed Target Resolver tool, we retrieve each target from the SIMBAD database using their archival names and then commit them to our proposal.

 Once resolved, we re-name the targets "HR8799", "HD220657" and "HD218261", in the Name in the Proposal field respectively. 

We define the Category of our "HR8799" target as "Star" and provide the "F stars" and "Exoplanet Systems" Description keywords. For "HD220657" and "HD218261"we select the "CalibrationCategory and select the "Coronagraphic" and "Point spread functionDescription keywords.



Create Observations

Main article: APT Observations

With our targets specified, we can now begin fleshing out our proposal. In the APT, observations reside in one or more observation folders, located under the main Observations folder in the tree editor. Because we have decided to split our MIRI and NIRCam coronagraphic observations into two different coronagraphic observation sequences (at different epochs), we can create two separate observation folders. To create a new folder, we click on Observations in the tree editor and click the New Observation Folder button, creating a new observation folder with a new blank observation form inside that folder. When an observation folder is selected, a new observation can be created by clicking the Add button.

For ease, we will create each of the desired observation folders and observation templates as placeholders, specifying only the Label and observation NumberInstrumentTemplate and Target, prior to entering the specific details of each observation—this will make it much easier for us to specify various connections, such as PSF reference observations and special requirement links, as we craft our individual observations.  As such, we create two new observation folders containing 3 and 9 observations, respectively, and specify them as follows:

  1. Observation Folder 1: Label: "NIRCam Coronagraphic observations"

    1.  Observation 1
      • Number: we assign an Observation Number "1".
      • Label: we provide the Observation Label "HR 8799 - NIRCam - MASKLWB - Roll 1".
      • Instrument: we select "NIRCam" as the Instrument.
      • Template: we select the "NIRCam Coronagraphic Imaging" Template.
      • Target: we select "1 HR8799" as the Target.
    2.  Observation 2
      • Number: we assign an Observation Number "2".
      • Label: we provide the Observation Label "HR 8799 - NIRCam - MASKLWB - Roll 2".
      • Instrument: we select "NIRCam" as the Instrument.
      • Template: we select the "NIRCam Coronagraphic Imaging" Template.
      • Target: we select "1 HR8799" as the Target.
    3.  Observation 3
      • Number: we assign an Observation Number "3".
      • Label: we provide the Observation Label "Reference Star - NIRCam - MASKLWB".
      • Instrument: we select "NIRCam" as the Instrument.
      • Template: we select the "NIRCam Coronagraphic Imaging" Template.
      • Target: we select "3 HD218261" as the Target.
  2. Observation Folder 2: Label: "MIRI Coronagraphic observations"

    •  Observation 4
      • Number: we assign an Observation Number "4".
      • Label: we provide the Observation Label "HR8799 - MIRI - 1065C - Roll 1".
      • Instrument: we select "MIRI" as the Instrument.
      • Template: we select the "MIRI Coronagraphic Imaging" Template.
      • Target: we select "1 HR8799" as the Target.
    •  Observation 5
      • Number: we assign an Observation Number "5".
      • Label: we provide the Observation Label "HR8799 - MIRI - 1140C - Roll 1".
      • Instrument: we select "MIRI" as the Instrument.
      • Template: we select the "MIRI Coronagraphic Imaging" Template.
      • Target: we select "1 HR8799" as the Target.
    •  Observation 6
      • Number: we assign an Observation Number "6".
      • Label: we provide the Observation Label "HR8799 - MIRI - 1550C - Roll 1".
      • Instrument: we select "MIRI" as the Instrument.
      • Template: we select the "MIRI Coronagraphic Imaging" Template.
      • Target: we select "1 HR8799" as the Target.
    •  Observation 7
      • Number: we assign an Observation Number "7".
      • Label: we provide the Observation Label "HR8799 - MIRI - 1065C - Roll 2".
      • Instrument: we select "MIRI" as the Instrument.
      • Template: we select the "MIRI Coronagraphic Imaging" Template.
      • Target: we select "1 HR8799" as the Target.
    •  Observation 8
      • Number: we assign an Observation Number "8".
      • Label: we provide the Observation Label "HR8799 - MIRI - 1140C - Roll 2".
      • Instrument: we select "MIRI" as the Instrument.
      • Template: we select the "MIRI Coronagraphic Imaging" Template.
      • Target: we select "1 HR8799" as the Target.
    •  Observation 9
      • Number: we assign an Observation Number "9".
      • Label: we provide the Observation Label "HR8799 - MIRI - 1550C - Roll 2".
      • Instrument: we select "MIRI" as the Instrument.
      • Template: we select the "MIRI Coronagraphic Imaging" Template.
      • Target: we select "1 HR8799" as the Target.
    •  Observation 10
      • Number: we assign an Observation Number "10".
      • Label: we provide the Observation Label "Reference Star - MIRI - 1065C".
      • Instrument: we select "MIRI" as the Instrument.
      • Template: we select the "MIRI Coronagraphic Imaging" Template.
      • Target: we select "2 HD220657" as the Target.
    •  Observation 11
      • Number: we assign an Observation Number "11".
      • Label: we provide the Observation Label "Reference Star - MIRI - 1140C".
      • Instrument: we select "MIRI" as the Instrument.
      • Template: we select the "MIRI Coronagraphic Imaging" Template.
      • Target: we select "2 HD220657" as the Target.
    •  Observation 12
      • Number: we assign an Observation Number "12".
      • Label: we provide the Observation Label "Reference Star - MIRI - 1550C".
      • Instrument: we select "MIRI" as the Instrument.
      • Template: we select the "MIRI Coronagraphic Imaging" Template.
      • Target: we select "2 HD220657" as the Target.

Note that while we may create these observations in any order, it is essential that we assign the "Observation Number" for each observation as stated above (i.e., organized according to the observing strategy we previously devised). This is because within the APT, observations occur according to increasing observation number.


Specify Observations

Main article:  APT Observation Templates

With our proposal fleshed out, we will now return to each observation and fill out the observation specifications in the selected observation template. For both the MIRI and NIRCam coronagraphic imaging modes, an observer has control over three primary parameters:

The allowed values are documented and maintained in the MIRI Coronagraphic Imaging Template Parameters and NIRCam Coronagraphic Imaging Template Parameters pages, respectively.

NIRCam Coronagraphic Imaging Observations

Main article: NIRCam Coronagraphic Imaging APT Template

The NIRCam Coronagraphic Imaging Template Parameters article documents the allowed values for this template. We define these for our observations with the following template specific information (in accordance with the ETC). The strategy here is to generate as many frames as possible (RAPID, 10 Groups/Integration), avoid saturation and adjust the Number of Integrations per Exposure to yield a SNR of ~100 on HR 8799 b for all filters. For the reference star which is taken with a 5-point small-grid-dither pattern (the maximum for the bar, to guarantee an optimal PSF subtraction), the Number of Integrations per Exposure is logically 5 times smaller, 4 when not divisible by 5, to keep the total time and photon count on the reference star approximately the same as on HR 8799). We request Astrometric Confirmation Images for the observation on the science target. Indeed, those are necessary to know the position of the star when it is behind the occulter (with respect to other stars in the field) and hence to get a precise astrometric calibration for the planet b whose orbital refinement is of interest for the community. This astrometric calibration is not necessary for the reference star. We will need to define a number of parameters, including Coronagraphic Mask, Acquisition Target Parameters (Brightness, Filter, Readout Pattern, Number of Groups/Integration), ETC Wkbk. Calc. IDAstrometric Confirmation Image ParametersDither Pattern, Subarray, Science Filters, Science Readout Patterns, Number of Groups/Integration, Number of Integrations/Exposure, and NIRCam PSF Reference Observation.  We choose the following parameters for our observations:

  1. Observation Folder 1: Label: "NIRCam Coronagraphic observations"

    •  Observation 1: "HR 8799 - NIRCam - MASKLWB - Roll 1"
      • Coronagraphic Mask: we select the "MASKLWB" Coronagraphic Mask
      • Target Acquisition Parameters
        • Target ACQ: we specify the Acquisition Target to be the "Same Target as Observation" and the Acquisition Target Brightness type to be "BRIGHT (ND Square)"
        • Acq Exposure Time: we select the "BRIGHT2" Acquisition Readout Pattern; specify Acquisition Number of Groups/Integration as "65" and provide the name of the ETC Wkbk. Calc. ID we used to arrive at these exposure settings.
      • Astrometric Confirmation Image Paramaters
        • we specify that we do not need to Obtain Astrometric Confirmation Images by selecting "Yes"
      • Science Exposures
        • Subarray: we select the "SUB320" Science Subarray
        • Dither Pattern: for the Dither Pattern we select "NONE"
        • Filters: exposures are grouped by filter, so for each set of exposures to be executed we "Add" a new filter and configure it as follows:
          • #1: we select the "F335M" Science Filter; "RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "5"
          • #2: we select the "F250M" Science Filter; "RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "8"
          • #3: we select the "F300M" Science Filter; "RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "7"
          • #4: we select the "F360M" Science Filter; "RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "4"
          • #5: we select the "F410M" Science Filter"RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "5"
          • #6: we select the "F430M" Science Filter"RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "12"
          • #7: we select the "F460M" Science Filter"RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "60"
          • #8: we select the "F480M" Science Filter"RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "60"
      • PSF Reference Observations
        • PSF Reference Observations: we select "Reference Star– NIRCam - MASKLWB (Obs 3)" as our first designated PSF Reference Observation.
        • PSF Reference Observations: we select "HR 8799 - NIRCam - MASKLWB - Roll 2 (Obs 2)" as our second designated PSF Reference Observation.
    •  Observation 2: "HR 8799 - NIRCam - MASKLWB - Roll 2"
      • We keep the same Coronagraphic Mask,Target Acquisition Parameters, Astrometric Confirmation Image Parameters, Science Exposure parameters  as Obs 1 (i.e. "HR 8799 - NIRCam - MASKLWB - Roll 1").
      • PSF Reference Observations
        • PSF Reference Observations: we select "Reference Star– NIRCam - MASKLWB (Obs 3)" as our first designated PSF Reference Observation.
        • PSF Reference Observations: we select "HR 8799 - NIRCam - MASKLWB - Roll 1 (Obs 1)" as our second designated PSF Reference Observation.
    •  Observation 3: "Reference Star - NIRCam - MASKLWB"
      • Target Acquisition Parameters
        • Target ACQ: we specify the Acquisition Target to be the "Same Target as Observation" and the Acquisition Target Brightness type to be "BRIGHT (ND Square)"
        • Acq Exposure Time: we select the "BRIGHT2" Acquisition Readout Pattern; specify Acquisition Number of Groups/Integration as "65" and provide the name of the ETC Wkbk. Calc. ID we used to arrive at these exposure settings.
      • Astrometric Confirmation Image Paramaters
        • we specify that we do not need to Obtain Astrometric Confirmation Images by selecting "No"
      • Science Exposures
        • Subarray: we select the "SUB320" Science Subarray
        • Dither Pattern: for the Dither Pattern we select "5-POINT-BAR"
        • Filters: exposures are grouped by filter, so for each set of exposures to be executed we "Add" a new filter and configure it as follows:
          • #1: we select the "F335M" Science Filter; "RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "1"
          • #2: we select the "F250M" Science Filter; "RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "2"
          • #3: we select the "F300M" Science Filter; "RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "2"
          • #4: we select the "F360M" Science Filter; "RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "1"
          • #5: we select the "F410M" Science Filter"RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "1"
          • #6: we select the "F430M" Science Filter"RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "2"
          • #7: we select the "F460M" Science Filter"RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "12"
          • #8: we select the "F480M" Science Filter"RAPID" Science Readout Patterndefine the Number of Groups/Integration as "10" and Number of Integrations/Exposure as "12"
      • PSF Reference Observations
        • We check the This is a PSF Reference Observation box, indicating that it is a PSF observation. 

MIRI Coronagraphic Imaging Observations

Main article: MIRI Coronagraphic Imaging APT Template

In accordance with out advance work in the ETC (see Step-by-Step ETC Guide for NIRCam and MIRI Coronagraphy of HR8799 b article), we define the MIRI observations with the template specific information for MIRI Coronagraphic Imaging. Unlike for NIRCam, it is allowed to use a large number of Groups/Int (recommended for sake of calibration) and thus we fix the Number of Integrations/Exposure to 5 (1 for the reference star) and vary the Groups/Int to also achieve a SNR of ~100 on HR 8799 b for each of the 3 filer/mask setup. We use the same readout parameter for the reference star to guarantee the same frame background level. The reference star for MIRI is taken, as for NIRCam, with a 5-point small-grid-dither (9-point would be overshoot considering HR 8799 is an easy target at a separation where the SNR is limited by the background rather than by speckle noise).  We will need to define a number of parameters, including Coronagraphic Filter/Mask, Acquisition Target Parameters (Brightness, Filter, Quadrant, Readout Pattern, Number of Groups/Integration), ETC Wkbk. Calc. IDDither Pattern, Science Readout Patterns, Number of Groups/Integration, Number of Integrations/Exposure, and MIRI PSF Reference Observation.  We choose the following parameters for our observations:

For your own tracking purposes, it is recommended you include the ETC workbook and calculation ID number in the Acq ETC Wkbk Calc ID field so the TA SNR calculations can be verified by Instrument Scientists during technical reviews after the proposal is accepted.  In this example, we do not include an ETC workbook ID number in the provided APT file since a unique ID number is generated when an example workbook is added to a user's list of workbooks.


  1. Observation Folder 2: Label: "MIRI Coronagraphic observations" 
    •  Observation 4: "HR8799 - MIRI - 1065C - Roll 1":
      • Target Acquisition Parameters
        • Target ACQ: we select the "FND" Target Acquisition Filter.
        • Acq Exposure Time: we select the "FAST" Acquisition Readout Pattern; specify Acquisition Number of Groups/Integration as "44" and provide the name of the ETC Wkbk. Calc. ID we used to arrive at these exposure settings.
        • Acq Quadrant: we select Target Acquisition Quadrant "1" in which to perform the initial TA
      • Coron Parameters
        • Coron Filter: we select the "4QPM/F1065C" Coronagraphic Mask/Filter combination
        • Exposure Time: we select the "FAST" Readout Pattern; specify the Number of Groups/Integration as "26"; the Number of Integrations/Exposure as "5" and the Number of Exposures/Dither as "1".
        • Dither Type: we select "NONE"
      • PSF Reference Observations
        • PSF Reference Observations: we select "Reference Star– MIRI - 1065C (Obs 10)" as our first designated PSF Reference Observation.
        • PSF Reference Observations: we select "HR 8799 - MIRI - 1065C- Roll 2 (Obs 7)" as our second designated PSF Reference Observation.
    •  Observation 5: "HR8799 - MIRI - 1140C - Roll 1":
      We keep the same Target Acquisition Parameters, Coron parameters and PSF Reference Observation parameters as Obs 4 (i.e. "HR8799 - MIRI - 1065C - Roll 1").
      • Coron Parameters
        • Coron Filter: we select the "4QPM/F1140C" Coronagraphic Mask/Filter combination
        • Exposure Time: we select the "FAST" Readout Pattern; specify the Number of Groups/Integration as "27"; the Number of Integrations/Exposure as "5" and the Number of Exposures/Dither as "1".
      • PSF Reference Observations
        • PSF Reference Observations: we select "Reference Star– MIRI - 1140C (Obs 11)" as our first designated PSF Reference Observation.
        • PSF Reference Observations: we select "HR 8799 - MIRI - 1140C- Roll 2 (Obs 8)" as our second designated PSF Reference Observation.
    •  Observation 6: "HR8799 - MIRI - 1550C - Roll 1":
      We keep the same Target Acquisition Parameters, Coron parameters and PSF Reference Observation parameters as Obs 4 (i.e. "HR8799 - MIRI - 1065C - Roll 1").
      • Coron Parameters
        • Coron Filter: we select the "4QPM/F1550C" Coronagraphic Mask/Filter combination
        • Exposure Time: we select the "FAST" Readout Pattern; specify the Number of Groups/Integration as "26"; the Number of Integrations/Exposure as "5" and the Number of Exposures/Dither as "1".
      • PSF Reference Observations
        • PSF Reference Observations: we select "Reference Star– MIRI - 1550C (Obs 12)" as our first designated PSF Reference Observation.
        • PSF Reference Observations: we select "HR 8799 - MIRI - 1550C- Roll 2 (Obs 9)" as our second designated PSF Reference Observation.
    •  Observation 7: "HR8799 - MIRI - 1065C - Roll 2"
      We keep the same Target Acquisition Parameters, Coron Parameters as Obs 4 (i.e. "HR8799 - MIRI - 1065C - Roll 1").
      • PSF Reference Observations
        • PSF Reference Observations: we select "Reference Star– MIRI - 1065C (Obs 10)" as our first designated PSF Reference Observation.
        • PSF Reference Observations: we select "HR8799 - MIRI - 1065C - Roll 1 (Obs 4)" as our second designated PSF Reference Observation.
    •  Observation 8: "HR8799 - MIRI - 1140C - Roll 2"
      We keep the same Target Acquisition Parameters, Coron Parameters as Obs 5 (i.e. "HR8799 - MIRI - 1140C - Roll 1").
      • PSF Reference Observations
        • PSF Reference Observations: we select "Reference Star– MIRI - 1140C (Obs 11)" as our first designated PSF Reference Observation.
        • PSF Reference Observations: we select "HR8799 - MIRI - 1140C - Roll 1 (Obs 5)" as our second designated PSF Reference Observation.
    •  Observation 9: "HR8799 - MIRI - 1550C - Roll 2"
      We keep the same Target Acquisition Parameters, Coron Parameters as Obs 6 (i.e. "HR8799 - MIRI - 1550C - Roll 1").
      • PSF Reference Observations
        • PSF Reference Observations: we select "Reference Star– MIRI - 1550C (Obs 12)" as our first designated PSF Reference Observation.
        • PSF Reference Observations: we select "HR8799 - MIRI - 1550C - Roll 1 (Obs 6)" as our second designated PSF Reference Observation.
    •  Observation 10: "Reference Star - MIRI - 1065C"
      • Target Acquisition Parameters
        • Target ACQ: we select the "FND" Target Acquisition Filter.
        • Acq Exposure Time: we select the "FAST" Acquisition Readout Pattern; specify Acquisition Number of Groups/Integration as "4" and provide the name of the ETC Wkbk. Calc. ID we used to arrive at these exposure settings.
        • Acq Quadrant: we select Target Acquisition Quadrant "1" in which to perform the initial TA.
      • Coron Parameters
        • Coron Filter: we select the "4QPM/F1065C" Coronagraphic Mask/Filter combination.
        • Exposure Time: we select the "FAST" Readout Pattern; specify the Number of Groups/Integration as "26"; the Number of Integrations/Exposure as "1" and the Number of Exposures/Dither as "1".
        • Dither Type: we select "5-POINT-SMALL-GRID".
      • PSF Reference Observations
        • We check the This is a PSF Reference Observation box, indicating that it is a PSF observation. 
    •  Observation 11: "Reference Star - MIRI - 1140C"
      We keep the same Target Acquisition Parameters, Coron Parameters as Obs 6 (i.e. "HR8799 - MIRI - 1550C - Roll 1").
      • Coron Parameters
        • Coron Filter: we select the "4QPM/F1140C" Coronagraphic Mask/Filter combination
        • Exposure Time: we select the "FAST" Readout Pattern; specify the Number of Groups/Integration as "27"; the Number of Integrations/Exposure as "1" and the Number of Exposures/Dither as "1".
        • Dither Type: we select "5-POINT-SMALL-GRID".
      • PSF Reference Observations
        • We check the This is a PSF Reference Observation box, indicating that it is a PSF observation. 
    •  Observation 12: "Reference Star - MIRI - 1550C"
      We keep the same Target Acquisition Parameters, Coron Parameters as Obs 6 (i.e. "HR8799 - MIRI - 1550C - Roll 1").
      • Coron Parameters
        • Coron Filter: we select the "4QPM/F1550C" Coronagraphic Mask/Filter combination
        • Exposure Time: we select the "FAST" Readout Pattern; specify the Number of Groups/Integration as "102"; the Number of Integrations/Exposure as "1" and the Number of Exposures/Dither as "1".
        • Dither Type: we select "5-POINT-SMALL-GRID"
      • PSF Reference Observations
        • We check the This is a PSF Reference Observation box, indicating that it is a PSF observation. 



Define Special Requirements

Main article: APT Special Requirements
Adding Special Requirements in APT


In the APT, Special Requirements (SRs) are defined parameters used to observation scheduling for scientific reasons, or to indicate other situations requiring specific actions. In order to fulfill the guidelines of our proposed observing strategy (see parent article), we will require the use of two kinda of special requirements: Timing Special Requirements, which are used to restrict the scheduling of JWST observations by timing constraints, and Aperture Position Angle Special Requirements, which are used to restrict the scheduling of observations by position angle constraints. 

For the "NIRCam Coronagraphic observations" folder, the SRs placed are as follows:

NIRCam Coronagraphic Observations (Special Requirements)

Timing Special Requirements:

To ensure the observations execute together and in the order provided:

  • SEQUENCE OBSERVATIONS 1, 2, 3, NON-INTERRUPTIBLE
    1. We select "Reference Star - NIRCam - MASKLWB (Obs 3)":
    2. Add a  Timing → Group/Sequence Observations Link:
      • In the Observation list we select observations 1, 2 and 3.
      • We check the Sequence and Non-interruptible checkboxes

Aperture Position Angle Special Requirements:

HR 8799 b is always well positioned with respect to NIRCam's MASKLWB axis (horizontal).  Nevertherless, for training purposes, we set two "Aperture PA Range" requirements which correspond roughly to the whole observability intervals and for both "Roll 1" and "Roll 2"  (see parent article).

  • APERTURE PA RANGE: 59 to 75 Degrees (V3 58.599 to 74.599) AND 211 to 250 Degrees (V3 210.599 to 249.599)

    1. We select
      1. "HR 8799 - NIRCam - MASKLWB - Roll 1 (Obs 1)"
      2. "HR 8799 - NIRCam - MASKLWB - Roll 2 (Obs 2)"
    2. We add 2 Position Angle  PA Range special requirements:
      • Aperture PA Range: we define as "59" to "75" Degrees.
      • Aperture PA Range: we define as "211" to "250" Degrees.


  • APERTURE PA OFFSET 2 from 1 by 7 to 14 Degrees (Same offsets in V3)
    1. We select "HR 8799 - NIRCam - MASKLWB - Roll 1 (Obs 1)
    2. We add a Position Angle → PA Offset Link:
      • Orient observation: "HR 8799 - NIRCam - MASKLWB - Roll 2 (Obs 2)"
      • Offset from: "HR 8799 - NIRCam - MASKLWB - Roll 1 (Obs 1)"
      • Min PA offset: we define as "7" Degrees
      • Max PA Offset we define as "14" Degrees
      • Reference Axis: we select "Aperture"

For the "MIRI Coronagraphic observations" folder, we impose the following special requirements  on the observations: 

MIRI Coronagraphic Observations (Special Requirements)

Timing Special Requirements:

To ensure the observations execute together and in the order provided—minimizing possible thermal variations differentially affecting the acquired PSFs, as well as the number of rolls and slews—we group all of the MIRI observations using a non-interruptible sequence:

  • SEQUENCE OBSERVATIONS 4, 5, 6, 7, 8, 9, 10, 11, 12, NON-INTERRUPTIBLE
    1. We select "HR 8799 - MIRI- 1065C - Roll 1 (Obs 4)"
    2. Add a  Timing → Group/Sequence Observations Link:
      • In the Observation list we select observations 4, 5, 6, 7, 8, 9, 10, 11 and 12.
      • We check the Sequence and Non-interruptible checkboxes

Aperture Position Angle Special Requirements:

In order to position HR 8799 b in quadrant 1 at more than 30º from the 4QPM vertical most axis, we restrict the aperture PA (APA) to > 89º and < 104º. According to our previous work in the CVT (see parent article) we find that restricting the APA of the Roll Angle 1 to 89-103° yields good target positioning at Roll Angle 2. Additionally it allows a favorable positioning of planet c in quadrant 4. We set the aperture PA offsets from the minimum  (~7º) to relax as much as possible the already stringent scheduling constraint for MIRI to the maximum (~14°). At the angular separation of b, ~7º is good enough.

We place the following APA Special Requirements on our observations:

  • APERTURE PA RANGE 89.20 to 103.55 Degrees (V3 84.750 to 99.100)

    1. We select "HR 8799 - MIRI- 1065C - Roll 1 (Obs 4)"
    2. We add a Position Angle  PA Range special requirement:
      • Aperture PA Range: we define as "89.20" to "103.55" Degrees.

  • APERTURE PA OFFSET 7 from 4 by 7 to 14 Degrees (Same offsets in V3)

    1. We select "HR 8799 - MIRI- 1065C - Roll 1 (Obs 4)"
    2. We add a Position Angle → PA Offset Link:
      • Orient observation: "HR 8799 - MIRI- 1065C - Roll 1 (Obs 4)"
      • Offset from: "HR 8799 - MIRI- 1065C - Roll 2 (Obs 7)"
      • Min PA offset: we define as "7" Degrees
      • Max PA Offset we define as "14" Degrees
      • Reference Axis: we select "Aperture"

    3. Repeat 1. and 2. for Obs 5 & 8 and Obs 6 & 9

Run Visit Planner

Main article: APT Visit Planner
 APT Visit Planner,   Using Aladin and APT Visit Planner

With the targets, observations and special requirements of our proposal now defined, our next step is to verify that our observation sequences can be executed as specified. To do so, we will make use of the APT Visit PlannerThe Visit Planner (VP) is a tool that performs detailed scheduability checks for observations in the APT, including visibility, constraints checking and guide star availability. The VP may be run on individual observations, collection of observations, and ultimately on the entire set of proposed observations prior to proposal submission.

In the form editor in APT, we first select the MIRI coronagraphic observations folder, and select the Visit Planner icon from the top tool bar. Clicking the Update Display button in the active GUI window, we run the VP on all of the observations, and their associated visits, in the folder. Once the schedulability of the MIRI Coronagraphic observations is confirmed (the VP displaying green checks on the observations), we repeat this process on the NIRCam coronagraphic imaging folder. 

For an overall observation to be schedulable, the constraints for all visits need to have a window of schedulability at the same time. Running the Visit Planner, we find that the observability of our targets (with respect to the observatory as a function of time) and guide star availability, combined with the overlap of all of our special requirements, results in a scheduling window of ~2 weeks in length for each instrument. Below are two screen captures (Figure 1 & 2)  of the Visit Planner for both NIRCam and MIRI showing the available time intervals that satisfy the constraints of each observation in our program:

Figure 1. Observability of the NIRCam observations.

Visit Planner screenshot: observability of the three NIRCam observations.
Figure 2. Observability of the MIRI observations.

Visit Planner screenshot: observability of the nine MIRI observations. The CVT was used to narrow down the timing constraints to avoid having planet b too close to the 4QPM vertical axis (5º from the detector axis).


Run Smart Accounting

Main article:  APT Smart Accounting
See also:  JWST Observing Overheads and Time Accounting Overview

With the scheduability of our coronagraphic sequences verified, we can now run the APT Smart Accounting on our proposed observations to see whether charged overhead time can be reduced. To run the Smart Accounting tool, we select the main Observations folder in the Tree editor and select the Visit Planner tool in the top tool bar, providing access to the Run Smart Accounting button. 

Because our set of observations is in a non-interruptible sequence, it will obviously only need one major slew at the beginning of the sequence. Smart Accounting will catch and correct this and reduce our reported overheads. Prior to running the Smart Accounting tool, the APT reports 1.66 hours of Science time and 13.86 hours of Charged time (as reported in the proposal cover page); once run, the total charged time is reduced to 11.17 hours.