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DeltaRho 350 + QHY600

The exploded view to the right shows the components of the Planewave Delta Rho 350 + QHY600 CMOS camera systems, which were installed network-wide between Q1 2023 and Q1 2024. From the right to left, the components are: the Delta Rho 350 telescope tube, the Gemini Focus unit, a Uniblitz shutter, the LCO filter wheel, and the QHY600 CMOS camera. There is additional interface hardware shown to bolt the components together.

2023-05-15: The Release Notes (version 1.0) are now available.

2024-07-19: A log of discovered and corrected issues was created.

Exploded view of the Delta Rho 350 telescope and instrument package.
Format 9576 x 6388 pixels, 3.76 micron pixels size
FOV (arcmin) 1.9 x 1.2 degrees readout mode full_frame
30'x30' in readout mode central30x30
Pixel size (1x1 binning, arcsec) ~0.74"/pixel
Default binning 1 x 1
Cycle time (readout+overhead; 1x1 binning, s) < 6 seconds full_frame
< 3 seconds central30x30
Read noise (e-) ~ 3 to 3.5 e-
Gain (e-/ADU) 0.7 e-/ADU
Dark current (e-/pix-s) TBD
Filters Sloan u', g', r', i', Johnson-Cousins B, V, Pan-STARRS w, z_s, Ha, O[III], S[II], exoplanet (500nm redpass)

Notes on filters:

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, submitted.
ADS entry of arXiv submission.

Deployment Status

Site Telescope ID Instrument Type Camera code Status
COJ clma:0m4a DeltaRho+QHY600 sq36 operational
COJ clma:0m4b DeltaRho+QHY600 sq37 operational
CPT aqwa:0m4a DeltaRho+QHY600 sq38 operational
TFN aqwa:0m4a DeltaRho+QHY600 sq32 operational
TFN aqwa:0m4b DeltaRho+QHY600 sq33 operational
LSC aqwa:0m4a DeltaRho+QHY600 sq34 operational
LSC aqwb:0m4a DeltaRho+QHY600 sq35 operational
ELP aqwa:0m4a DeltaRho+QHY600 sq31 operational
OGG clma:0m4b DeltaRho+QHY600 sq30 operational
OGG clma:0m4c DeltaRho+QHY600 sq40 operational