Open Cluster Hunt and my First Planetary!
1st February 2005
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M46 - Open Cluster in Puppis

A great 9 hour session, with some sleep in between. The first really clear night in over a week, and the first clear morning in over a week, although the moon really washed out the sky this morning as it was directly overhead (well, close enough). It was almost my first light after flocking the OTA and cleaning my mirror!

I spent some time last night evaluating the Andrews UW80degree 30mm (2") that Mark Hodson has leant me. My initial impressions after my 10 minutes using it last week weren't the best, but after spending about an hour with it last night I like it a lot more. The field is nice and large and it is possible to immerse yourself in the view, having to look up/down/left/right to take in the whole field.


Conditions were very good. Seeing: Good to very good. Transparency: Good. Wind: Calm. Temperature: ~19deg C.

EyePiece Report


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Andews 2" UW80deg 30mm

I am still disappointed with the sharpness around the edges, there's probably almost 1/3rd of the view around the edges where the stars look like seagulls. But the more I used it, the more I got used to it and didn't find it as annoying as I did at first. My 50 degree 32mm (1.25") GSO plossl exhibits the same problems around the outer edges, but because of the wider field in the UW80 it's obviously much more noticeable.

I'd like to be able to compare it against the 30mm GSO SV, which has a 60-something degree field, to compare the edge sharpness and field-of-view in my f/5 dob. Like many others, I do think that either the SV or the Andrews UW80 will make a good budget widefield low power 2" eyepiece, as long as you learn to live with the aberrations around the edge of the field. I'd also like to try both with a 2" barlow to see what they're like at twice the magnification - hopefully i've got a loaner on it's way from Andrews soon.

Objects Observed

For my tests I went open cluster hunting in Canis Major and Puppis. I also took in my first planetary nebula!

M41 Open Cl. Open Cluster in Canis Major, close to Sirius
NGC2360 Open Cl. Open Cluster in Canis Major
NGC2362 Open Cl. Open Cluster in Canis Major
M46 Open Cl. Open Cluster in Puppis. My favourite for the night
M47 Open Cl. Open Cluster in Puppis
NC2438 Planetary Neb. Planetary Nebula on the northern edge of M46. My first planetary!
M93 Open Cl.

Open Cluster in Puppis

NGC2451 Open Cl.

Open Cluster in Puppis

NGC2477 Open Cl.

Open Cluster in Puppis

NGC2546 Open Cl.

Open Cluster in Puppis

M42 Nebula The great Orion Nebula
Saturn Planet In my 9mm the CD was visible more often than not, which is a sign of good seeing for me. My wife even saw the CD and banding on the planet for the first time.

I must say that M46 was my favourite! What a great open cluster, looks like a loose globular. I could make out a hint of NGC2438 on the northern edge of M46 with the Andrews UW80, and confirmed it's position when I put in my 9mm plossl, the grey ring was quite evident, although I did wish I had a OIII or UHC filter.

Other Thoughts

My thoughts on the flocking - I do think it made a distinct difference, especially when viewing Saturn. The glare around the planet was significantly reduced and contrast seemed enhanced.
It's hard to judge whether the clean mirror made a difference, the views of the night were very good, clean and crisp, so the mirror might've helped, but seeing was also good. In any case, a clean mirror can't hurt.

I got some sleep, and got up again the next morning to do some imaging of Jupiter. It was very close to the moon (probably about 2-3 degrees separating them). Seeing was pretty good, but not as good as last night. I got some good avi's of Jupiter, and then decided I may as well take some avi's of the moon while it's there.

I then turned to Mars, which was about 10-15 degrees above the horizon, right in the middle of Scorpius and Sagittarius, maybe about 10 degrees below Antares. It'll make a fine sight in the milky way when it's overhead. Mars must be a long long way away at the moment, because with my 9mm I could barely make it out as a disc, and no features at all were visible.

Anyway it was a great 9 hours, finally to have some clear skies and steady air was a pleasure. The images of Jupiter and Saturn taken that night/morning can be found in this thread on the IceInSpace Forum.
Limpet Controller
Astronomy and Electronics Centre
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