{%extends "base.html" %} {% block content %}

Contamination & Visibility Calculator


This tool is designed for the slitless observation modes of all JWST instruments. For slitless observations, the spectrum of a target star may be contaminated by partially overlapping spectra of nearby stars. For a given target, this contamination depends on the position angle (PA) at which the observations are taken. This tool simulates NIRISS SOSS observations of a given target, and produces an estimate of the level of contamination as a function of the PA of the observation, thus making it useful to plan observations at the optimal PA. The tool also computes the JWST accessibility windows of the target, along with the corresponding accessible PAs for the chosen instrument/observation mode.

Potential caveats:

If there are any questions regarding these caveats please send us a ticket through the JWST help desk and we will get back to you shortly.

{{ form.hidden_tag() }} {% include 'target_resolve.html' %}
R.A.
{{ form.ra(value=form.ra.data, size=10, rows=1, class='form-control') }}
Decimal Degrees
The right ascension of the target
Decl.
{{ form.dec(value=form.dec.data, size=10, rows=1, class='form-control') }}
Decimal Degrees
The declination of the target
{% for error in form.ra.errors %}

{{ error }}

{% endfor %} {% for error in form.dec.errors %}

{{ error }}

{% endfor %}

PA
{{ form.v3pa(value=form.v3pa.data, size=10, rows=1, class='form-control') }}
Degrees
The position angle of the telescope Enter -1 to calculate ALL position angles. Enter any float between 0 - 360 for a single position angle.
{% for error in form.v3pa.errors %}

{{ error }}

{% endfor %}

Year
{{ form.epoch(value=form.epoch.data, size=10, rows=1, class='form-control') }}
The 4-digit year of the planned observations
{% for error in form.epoch.errors %}

{{ error }}

{% endfor %}

{{ form.mode_submit(id='modesubmit', style="visibility: hidden;") }}
\(T_\text{eff}\)
{{ form.teff(size=10, rows=1, class='form-control') }}
Kelvin
The effective temperature of the companion
\(\Delta\) Gmag
{{ form.delta_mag(size=10, rows=1, class='form-control') }}
\(\Delta\) Gmag = Gmag\(_\text{Target}\) - Gmag\(_\text{Companion}\)
Distance
{{ form.dist(size=10, rows=1, class='form-control') }}
arcseconds
The distance of the companion from the target
PA
{{ form.pa(size=10, rows=1, class='form-control') }}
Degrees
The position angle of the companion relative to the target
{% for error in form.teff.errors %}

{{ error }}

{% endfor %} {% for error in form.delta_mag.errors %}

{{ error }}

{% endfor %} {% for error in form.dist.errors %}

{{ error }}

{% endfor %} {% for error in form.pa.errors %}

{{ error }}

{% endfor %}

{{ form.calculate_submit(class="btn btn-success") }} Calculate only the visibility of the target.


{{ form.calculate_contam_submit(disabled=form.calculate_contam_submit.disabled, class="btn btn-success") }} Calculate the visibility and the contamination. Please be patient, this calculation takes a while.

{% endblock %}