News & Annoucements

FLOYDS slit errors

1 Aug 2018

We've recently discovered two errors that may affect users of the FLOYDS spectrographs on the 2m telescopes.

  • Beginning on the night of July 10 at Haleakala (OGG) and on July 11 at Siding Spring (COJ), the slit position angle for FLOYDS spectra was fixed at 0 degrees for all observations. The header variables (ROTMODE=SKY, ROTSKYPA=0.0) show this, but of course, these setting are not what was indicated in the observation request. This bug was fixed on July 31, during the OGG night.
  • Beginning on the night of July 25 at Haleakala, the FLOYDS controller malfunctioned, causing errors in slit selection. As a results, the slit widths used for spectra do not necessarily correspond to the requested slit widths. The controller was reset (which fixed the problem) on July 31. If you received FLOYDS spectra within this time frame, inspect the header information to determine whether you got the slit width that you expected. In some cases, the header value (keyword=APERWID) is "UNKNOWN".

If these errors render your FLOYDS spectra unusable, please let us know (email:, and we will refund the hours to your project.

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