Seeing in Canberra

GeoffMc (Geoff) · #1 27-09-2010, 06:57 AM

Hi All. I am after input regarding the quality of seeing in Canberra, and astronomical seeing in general. Over the last month of using a 12" from the north of Canberra, the seeing has been so poor that only the major belts on Jupiter have been visible. Last night I managed to split rho Oph (3.5") easily, but gamma Cor Aust (2.7" separation) only just. This is pretty poor. I then waited until Jupiter was near culmination, but the seeing only got worse and even less detail was visible on the planet. Is it like this year round, due to local effects, just the luck of the draw? Are there any preferred observing sites in or around the ACT? Any other experiences will be welcome.

Geoff Mc

pgc hunter · #2 27-09-2010, 12:55 PM

Lots of reports of poor seeing around SE Aus this season. Not much better here, last night Jupiter was boiling and waving like a flag! Some very poor conditions have also been reported lover the last few months by imagers in SA, so it seems to be a running gag this season. Sometimes the local environment creates poor seeing. Observing in heavily built up areas, concrete pavements etc all radiate heat and buildings, hills and structures will disturb air flow. Ideally one should observe from a grassy flat area on the windward side of any buildings/hills and other obstructions, but obviously this is easier said than done.

higginsdj · #3 27-09-2010, 09:46 PM

My observatory is in North Canberra and photographically, my seeing continues to be roughly my long term average with a FWHM of around 7-8 pixels. Over the past month its been windy locally and 100% cloud cover by midnight means a lot of moisture in the air which doesn't help.

Cheers

GeoffMc (Geoff) · #4 28-09-2010, 06:10 AM

Thanks, David. Enjoyed looking at photos of your observatory, by the way. Impressive.

My understanding is that angular resolution depends on the telescope/imager combination. What does the FWHM of 7-8 pixels equate to in arc second resolution in your observatory, David?

Geoff Mc

higginsdj · #5 28-09-2010, 06:31 AM

Hi Geoff,

I don't know how ACP does the calculation (the software that runs my observatory), I just monitor it and see maybe +/- 1 from the average (unless my images are out of focus).

Cheers