It’s another clear night sky as I write this – but the Moon is full and it’s not a good time to be taking images. However, only about three or four more days and dark evening skies will be back.
So let’s check the ten day weather forecast:
Oh, crap! Cloudy skies predicted for the next ten nights in a row! By which time the b@$#!&* Moon will be almost back again… 😶
I took the above two hour exposure of M20 on 3rd September, it was the third and final image of a field night with Macarthur Astronomical Society, when the Moon was a four day old crescent and less bothersome. I have already posted the other two images: Crescent Moon and Cat’s Paw Nebula.
This was a two hour exposure of one of the sky’s most charming nebulae. It’s three main lobes, separated by dark lanes radiating from the centre, contribute to its name.
The Trifid is part of a much larger nebulous complex which also includes M8, the Lagoon Nebula. Some of the complex can be seen as a faint reddish background colour.
The nebula M20 is viewable in binoculars and can be picked out in small telescopes as a fuzzy patch about three quarters of the size of the Moon.
As I mentioned in my previous post, this image marks my return to image guiding after a period of relying on good polar alignment and shorter exposures. With this object, the guiding worked consistently, considering I was using a new guide camera and had forgotten much of what I had previously learned about PHD2 Guiding
Designation: Messier 20, NGC 6514.
Visual magnitude: +6.3
Apparent size: 29′ x 27′
Diameter: 44 light years.
Distance: 5,200 light years.
Altitude during exposure: 31° above W. horizon.
The following is just technical stuff:
Exposure: 63 x 115.9 sec = 121 min.
Image acquisition: SharpCap.
|Telescope:||SkyWatcher Esprit||Type:||120ED triplet refractor|
|Focal:||840 mm F/7||Mount:||SkyWatcher EQ6-R Pro|
|Camera:||ZWO ASI 071 MC Pro
||Type:||CMOS 28.4mm 16 Mpx
|Optical aids:||Flattener: Y; filter: LP||Guiding:||Yes|
|Polar aligning:||QHYCCD PoleMaster||Polar Error:||00’ 28”|
[ZWO ASI071MC Pro]
Auto Exp Target Brightness=100
Images © Roger Powell