How to create Finding Charts for Service Mode

In general, a finding chart has to be attached to each OB. Exceptions are possible for some instruments, in which case this is specified in the instrument-specific rules, which can be found by selecting the instrument from the pull-down instrument selector menu in the upper right of this web page.

General Finding Chart Requirements

Regardless of the instrument, finding charts must have all the following characteristics:

  • Clearly indicate the Observing Run ID.
  • Clearly indicate the PI Name.
  • Clearly indicate the OB Name or Target Name, as used in the OB to which it is attached.
  • The target(s) position(s) must be clearly indicated.
  • The entire instrument field-of-view must be shown.
  • North and East must be clearly indicated.
  • The scale must be indicated by drawing a bar and writing the bar length in arcseconds or arcminutes.
  • The wavelength range of the image must be indicated. Whenever possible, finding charts should have similar central wavelength to observations (e.g. DSS charts are often inappropriate for IR observations, e.g. near the galactic equator).
  • The images should be negative, i.e. dark objects on light background.
  • The output files must be in JPEG format and their size must be less than 1 Mbyte.
  • Positions of spectroscopic acquisition reference stars, if any, should be marked.
  • Spectroscopic finding charts must indicate the slit(s) position(s) clearly (unless slits are aligned along the parallactic angle)

Please verify that finding charts have sufficient quality and resolution. This can be done using p2 by attaching the finding chart and then clicking on the "thumbnail" version to see the full size version displayed in your browser.

Please read the P2 finding chart tutorial for a detailed description on how to attach finding charts to OBs.

How to create finding charts

p2 Finding Chart Generation service

Finding Chart Generation service, called p2fc, is integrated into p2. It allows the automated, non-interactive creation of finding charts for individual or multiple OBs at the push of a button for almost all of the current VLT and La Silla instruments that require finding charts. A detailed description and instructions for usage are available in the dedicated p2fc Finding Charts page.

A command line interface to p2fc is also available, via the Python p2api, allowing control over many of the characterisitics of the FC generation that are not possible in the single click implementation available in p2.

Other Finding Chart tools

Alternatively, valid finding charts can be produced with any software tool able to produce output files in JPEG format. For users who do not use the p2 finding chart generation service or instrument specific preparation tools like FIMS or KARMA, ESO recommends the use of the SkyCat-based finding chart tool. This tool provides another user-friendly interface to easily produce finding charts with the general characteristics described above.

Skycat, including the ESO Finding Chart Plugin, is now available from the ESO software repositories (see below), package name eso-skycat.

Additional rules for MUSE finding charts

WFM observations

Reference stars used to perform blind-offset during the target acquisition must be clearly marked.

When a WFM-NOAO OB uses the MoveToPixel acquisition template, but no blind-offset is used, the user should clearly mark on the finding chart a point-like source that can be used for accurate target centering.

If the WFM-AO mode is used, the TTS should be clearly marked.

The finding chart should show a field of 2'x2' size, indicating the IFU FoV with a box centred on the target coordinates.

NFM observations

The finding chart should show a field of 12"x12" size, indicating the IFU FoV with a box centred on the target coordinates. The source used as NGS should be clearly marked.

Finding Chart tools for MUSE

Finding charts for MUSE observations (all modes) can be easily prepared by using the Finding Chart Generation (p2fc) service available within the p2 environment.

Alternatively, for WFM-NOAO observations here we provide a code used to create a ds9 template showing the trapezoidal FoV of MUSE in WFM mode, together with the SGS metrology field regions surrounding it. A similar ds9 template showing also the region where a suitable TTS should be located for the case of WFM-AO observations can be downloaded here. One can simply load the file as a ds9 region.

Finally, MUSE ESO-compliant finding charts for all modes can be created by using fcmaker (Python 3 module). You can easily and quickly install the code using pip:  pip install fcmaker

Instrument selector

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