p2fc Finding Charts

Finding Chart Generation service called p2fc is integrated into p2. p2fc is derived from the excellent fcmaker software developed by F.Vogt. This service is also available on the p2-demo server.

The p2fc service supports most of the VLT/VLTI and La Silla instruments (see below).

To use the p2fc service, in p2 just select the OB(s) and then click the 'Generate Finding Chart(s)' button. If the instrument is supported, two ESO-compliant (see exceptions below) finding charts will then be added to the OB(s), provided there is space for them (up to 5 finding charts can be added to any OB, so there needs to be at least 2 slots free or already occupied by charts generated by the p2fc service -- note p2fc will replace any p2fc generated finding charts already attached to the OB).

p2fc can also be used from the command line via the Python p2api, which allows for greater control over finding chart generation not (yet) available from the web interface.

Creation and attachment of the finding charts takes typically 10-40 seconds per OB, depending on the instrument, target, and how many other finding charts are being created on the server at the same time. In some cases it can take up to 2mins, and in VERY rare cases perhaps as much as 10mins, to create the finding charts for an OB (if it takes longer than 5mins, you will probably get a timeout error, but the FC creation will actually continue on the server and if eventually successful the resulting FCs will eventually be attached to the OB).

The finding charts are created on the ESO p2fc server and directly attached to the OB(s) in the ESO p2 server. The speed of the computer you are connecting to p2 from, and its internet connection speed therefore have very little, if anything, to do with the time it takes to create a finding chart using the p2fc service. Most time is spent (by the server, not your computer) downloading images and catalogues from external servers.

As of Phase 2 for P106, for instruments supported by the ObsPrep tool (also integrated into p2) it is now possible to upload your own User Background Images for use with ObsPrep. In addition, if a User background Image is used in ObsPrep, it will also be used by p2fc to generate a third "custom" finding chart that will be attached to the OB. For more details see the dedicated User Background Images page.

"User" finding charts

While we expect that the p2fc finding charts will be suitable and adequate for most OBs, there still are many reasons why you may wish, or need, to attach your own, non-p2fc generated, finding charts to your OB(s), for example (but not limited to):

  • Your instrument is not supported
  • Necessary information not included in the p2fc Finding Chart
  • Your object of interest is not in Gaia DR2. Because the p2fc service makes extensive use of Gaia DR2 you may need to provide a custom FC, in case your object is not in Gaia DR2 (e.g. because it is a galaxy). However, this does not apply to simple point-and-shoot imaging observations of galaxies with instruments like, e.g. HAWK-I or MUSE.

In most cases it will still be useful to include the p2fc service finding charts, but to ALSO include your own finding chart(s).

In general, such user finding charts should still comply with the general and instrument specific requirements detailed here.

p2fc vs Observation Preparation Software

p2fc is NOT an Observation Preparation Software.The new ObsPrep tab in p2 allows interactive planning of the observations. For example, observing offsets can be defined and blind offset stars, AO stars, and VLT guide stars can be selected. Any action within this tab is directly reflected by an update of the respective parameters in the OB acquisition template, the science templates, and the target tab.

As of P106 ObsPrep can be used to define observing strategy for the following instruments:

  • FLAMES (arg_fast only)
  • MUSE
  • UVES

In particular, ObsPrep has replaced GUCT aka GuideCamTool for MUSE and HAWKI.

The following instruments/cases are NOT supported by ObsPrep, and the corresponding Observation Preparation Software must still be used for those OBs that require it, i.e.:

  • FIMS for FORS2: MOS, MXU, POL (not fast), IPOL (not fast) and OCC modes : Both p2fc AND FIMS finding charts must be generated and attached to the OBs for these modes.
  • FPOSS for FLAMES: Once the FPOSS setup has been created and attached to the OB, p2fc can then create the compliant Finding Chart.
  • KARMA for KMOS: finding charts must be created with KARMA. KMOS is NOT (currently) supported by p2fc.

p2fc supported instruments

As of P105, the following instruments are supported by the p2fc service -- please take note of the caveats, if any, for each instrument.


  • FORS2: OBs requiring FIMS setups must attach BOTH p2fc and FIMS finding chart(s).
  • MUSE
  • UVES

La Silla

  • EFOSC2
  • SOFI
  • WFI

Instruments NOT supported by p2fc

If your instrument is not in the list above it is NOT (currently) supported by p2fc. The following list is not exhaustive:

  • VIRCAM and OMEGACAM: do not require finding charts

Instrument selector