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MarsG76

Observation 9-10 November 2015 - 80mm and 8" SCT first comparison

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9th/10th November 2015

Equipment: 80x500mm refractor

Time: 22:46 - 00:40

47 Tucanae: showed a fuzzy patch with a distinctly denser/brighter core through a 40mm eyepiece (13X magnified).

The 11mm (45X) eyepiece started to show granulation through out the globular cluster. The view was quite faint but noticeable and distinct. The very obviously brighter core gradually became fainter and more disperse toward the edges of the globular disc. The edges were noticibly irregular.

NGC265 in Hydrus, dense star field just above beta Hydrus near east of 47 Tucanae. Heaps of faint stars but no nebulosity.

The orange star that reminded me of the Sagittarius supernova during last binocular observation is in constellation Reticulum, quite possibly alpha reticulum, right place and brightness, note that gamma reticulum seems orange on star maps.

Cluster in Sirius that I spotted last time I was observing is M41. A open cluster of stars, quite sparse and spread out cluster. Easily visible in binoculars and the 80mm refractor.

The Pleiades are looking awesome as usual, about a hundred stars visible, and the whole constellation visible in the 40mm eyepiece FOV. This is one object that I usually spend a fair bit of time observing. This view is one that needs the least possible magnification with the highest possible light gathering power, so the 80mm scope at 13X through the 40mm eyepiece is ideal... Atleast in my tool box.

Orion Nebula shows the whole Orion's sword in the 40mm eyepiece at 13X. This is definitely a view worth spending a bit of time observing. The running man nebula is very faintly showing through, but not anywhere near as obvious as the Orion Nebula.

Increasing the power to 45X with the 11mm TV Nagler reveals more nebulosity and the trapezium is very obvious.

Filters: Celestron OIII and Lumicon UHC filters seem to cut away too much light in the 80mm scope. There is more contrast through both but I preferred the view without either filter.

The Celestron UHC/LPR and Seben CLR filters did a better job in showing more nebulosity as well as increasing the contrast. Both had their advantages so it's hard to say which did a better job, but if I had to choose, I'd say the UHC/LPR had slightly the edge on the darker parts of the nebula.

The OIII and UHC filters are both too aggressive for the 80mm.

Equipment: NexStar 8SE

Time: 02:00 - 03:40

From approximately 2am, when the 80mm frac was setup to image the Orion's Sword, I wanted to compare the view in the 8SE to the 80mm refractor.

First I framed up on to the Orion Nebula, without the UHC filter the nebula glow was very obvious and the stars with in and around, such as the trapezium, were bright. Looking through the 40mm and 11mm eyepieces with and without the UHC filter, the nebulosity was quite obvious, the "moustache" and the fishes mouth were obvious with detail visible that was not visible in the refractor as expected. That said I do remember a more detailed view of the Orion Nebula in the past... Especially using the UHC filter.

The second object I located was the globular 47Tucanae. In the 40mm eyepiece the globular did not look any better than in the refractor so I replaced the eye piece to the 11mm Nagler. In the Nagler the globular was still quite dim but I did start to see granulation within the globular, but I was expecting to see the globular as a brighter object than what I'm seeing.

I put the reason to seeing such dim views in the globular and the Orion Nebula to the fact that I had to keep adjusting the autoguide star on the laptop screen, even though the screen was turned down to minimum, I figured that the white light was still bright enough to ruin my night adaption.... Then I thought, have a look at the corrector plate... Sure enough, nearly totally covered in dew. Oh well the observing part of the night is over, next time I'll have to run a RCA cable from the CGEM dew strap controller to the 8SE on alt-az mount and try these objects again. Hopefully in the next week there will be at least one more clear night before the moon lights things up again.

MG

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