Notes on filters:
- The narrow band filters are Baader Planetarium H alpha, O[III], and S[II]
- The Exoplanet filter is from Astrodon
Note on sensitivity:
- CMOS cameras usually have a lower red quantum efficiency. Users can expect a higher QE in the u' and g' filters, and a diminished sensitivity in the r', i', and z' filters.
Note on telescope tracking:
- The image quality is limited by the telescope mount. Fast drifting up to 20' over a few hours when unguided has been observed. Instead of single long exposures, users are advised to split longer exposures into shorter single exposures (< 2 minutes) and then stack afterward. Guiding should always be enabled.
Note on shutter operation:
- The camera itself is using electronic shuttering. An iris shutter is included in the system to allow for bias and dark calibrations without stray light contamination.
There is a delay between commanding an exposure, and the camera's actual start of the exposure. Also, due to the electronic rolling shutter of the CMOS chip, there is a row-by-row gradient of the effective time of exposure (the integration time remains constant).
To the best of our current knowledge, the correction to be applied, referenced to the UTSTART header keyword, is
time of exposure start = UTSTART + 0.5884 s + 4.0436e-5 s/row * row#
e.g., for the full frame readout, the center of the image is row #3194, and the effective exposure delay is: 0.5884 s + 4.40436e-5 s/row * 3194 rows = 0.729 s
The relation (offset and per row time) is the same for both the full_frame and central30x30 readout modes.
Acknowledgment:
All publications based on the new delta rho telescopes should adhere to LCO’s acknowledgment policy and include the following statement: “This paper is based on observations made with the Las Cumbres Observatory’s education network telescopes that were upgraded through generous support from the Gordon and Betty Moore Foundation.”
Citation:
The instrument is described in Harbeck et al. (2024), SPIE Astronomical Telescopes + Instrumentation Proceedings 13096-146.
ADS entry of 2024 SPIE Paper. Link to version on ArXiv.