MPO61, one of our shared 24-inch telescopes, has been a real workhorse for us in Texas. The partnership has been very proactive in keeping equipment running, and the cloud and seeing conditions are of professional level.
As of 2026/02/05 local date (more-or-less 20260206UT), a new camera has been installed. This is a QHY461, a 102Mpix beauty from QHY. Because of the long focal length of this telescope (4814mm), the camera is binned 2x2 to yield 31x24arcmin field of view with 0.323arcsec pixels. Even with binning, each image is 25MB, so be aware of storage!
In VPHOT, the new camera is identified as “MPO61qhy”.
We do not have new transformation coefficients yet for this camera, so bear with us. I’ll let you know when they are available.
Hi Arne,
why you are not binning 4x4 with this camera. Is the seeing that good that you need 0.323 arcsec/pixel? Larger binning would reduce storage significantly. I use my QHY600M on all my scopes (all about 2.6m FL) in 4x4 binning.
Josch
Hi Josch,
The seeing at MPO can be 1arcsec on some nights, so 2x2 yields 3pixels across the seeing disk. It also allows more flux per star per image without saturation when working with brighter stars. It is a judgement call whether 2x2 or 3x3 is the correct binning, but 4x4 is probably too coarse for this site.
We use a QHY600 at OC61 and bin 4x4 there because of the very long focal length. On the other extreme, DSO35 uses a QHY600 binned 1x1, because of the good seeing there and the very short focal length of the Delta-Rho.
There is always some trade-off between proper sampling and storage space!
Arne
The new MPO61 appears in VPhot’s “Available Images” page as RC610, not MPO61qhy. I had to scratch my bald head a bit before knowing what name to give my sequences based on the new setup (2MASS_J05393511_0247299-MPO61qhy-V and LDN1641N-MPO61qhy-V).
It would help to call the new equipment in VPhot an unequivocal name, perhaps FSM-MPO61qhy instead of RCOS610.
Hi Ari,
The images I’m getting from MPO list “MPO61qhy” in the Telescope column of the Available Images page. If you go to the FITS header, it lists RCOS610 as the telescope. So there are inconsistencies as to file naming and system identification inside of VPHOT. I’ll discuss this at the next management meeting and see if we can standardize things a bit more. Thanks for mentioning this!
Arne
There are other inconsistencies, this time within the AAVSOnet equipment descriptions.
If one looks at the Interactive map (AAVSOnet | aavso) and clicks on your telescope icon (e.g. BSM-NH2), one sees a set of descriptions. In the descriptions, there is a link under “More specifications” (e.g. Operations). By clicking on it, a new set of descriptions appears that does not agree with the previous one.
See for yourself: BSM-NH2 (Henden)
description
Telescope: 7" f/2.8 (Takahashi E180)
Camera: ASI183MM-Pro
Then, on the other link:
name:
BSM New Hampshire II
description:
Telescope: 7" f/2.8 (Takahashi E180)
Camera: ASI533MM-Pro
The same thing happens with other AAVSOnet telescope installations.