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15/05/10


gareththegeek

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Scope: C100 EDR 100mm/900mm

Lenses: Celestron Plossl 20, TeleVue Plossl 8, 2xBarlow

Location: Back Garden

Visibility: Good

Light Pollution: High

First Light with our new scope! While aligning the polar scope we realised that from the only level part of our garden Polaris is behind a tree. However I managed to see Polaris between a couple of leaves and we were ready to go.

Looking West we spotted the new crescent moon below Venus and decided a nice big target like the moon would be a good thing to practice on since we have not used an EQ mount before. We rotated the scope in the DEC axis and luckily that brought the moon into the view finder.

A bit of confusion followed as we attempted to align the finder scope. We couldn't seem to get the moon in the main scope and thought the view finder was pointing into the scope too much. Eventually we realised that the view finder should point towards the scope slightly so that their views converge and random sweeping of the sky got the moon in the main view. The view finder was aligned and the panic was over.

Immediately we could tell that this scope was far superior to the Bresser. Viewing the moon in the Celestron 20mm Plossl (our minimum magnification) we could see a clarity that we had never achieved with the Bresser even though by the time we got the scope aligned the moon was just above the horizon. The moon was past its best as poor seeing near the horizon made it appear to be swimming in water so we decided to move on to a new target, there would be plenty of time to see the moon later as it waxes.

We rolled the scope up in Right Ascension and found Venus in the finder scope, it was a real pleasure to use such a stable mount and good quality finder scope after suffering with the Bresser; Venus was centred within a minute of deciding to see it. Venus appeared starlike at 45x so we decided to try out our new 8mm TeleVue Plossl, Venus began to look slightly more like a disc and less like a star but there wasn't much in it. We tried using the inferior Barlow that came with the Bresser to get up to 225x. At this magnification we could tell that Venus was a planet not a star but couldn't see much of the phase so we decided to move on to a more rewarding target.

After a bit head scratching and pointing we worked out how to roll the scope to the south to point over the roof of our house and take a look at Saturn. At just 45x we could see the rings and the view was superior to anything we achieved with the Bresser even at 140x. Saturn was behind some thin clouds and yet this didn't seem to affect the view at all. Taking it up first to 112.5 and then onto 225 times magnification the view was absolutely stunning. I don't think I will ever be able to get tired of looking at Saturn which was always my favourite planet as a child, I never thought I would be able to actually see it! Saturn appeared as a milky yellow disc and at highest magnification we could make out a shadow cast by the rings on the planet's surface and as I studied it I thought I could just make out a subtle band of colour. We tracked Saturn for a little while, appreciating how easily we could follow it using an EQ mount by simply turning the RA knob.

We thought we'd have a look at M44 next being a favourite of our previous sessions but a patch of cloud seemed to be censoring Cancer so we decided to try out the optics splitting a binary star - Mizar. After crawling around on the floor and nearly breaking my neck I managed to get Mizar in sight virtually at the Zenith. At minimum magnification we could clearly see Mizar as two separate stars, I was amazed. Previously using the Bresser at maximum magnification and squinting at the star for a while I could just about tell that it was two stars. The C100 just split them effortlessly - this scope is a real bargain! At this point I moved over to Alcor and defocussed to test collimation. Alcor turned into a perfect bullside pattern, it would appear that the scope has come from the factory very well collimated indeed, no problems there.

To end the evening with a bang we thought we'd try and finally track down M81 and M82, a target which had elluded us previously due to the poor quality of the Bresser's finder scope. So I took a quick trot upstairs to the computer and fired up Stellarium. I looked up the coordinates of Dubhe, Phad and Bode's Galaxy (M81), I used the first value (the constant coordinate) reasoning that it would be wrong for the current time of day, but it would be wrong by the same amount for all targets.

Back in the garden we aligned the scope to Dubhe and positioned the setting circles to match the recorded coordinates then moved the scope to read the coordinates for M81. Sweeping back and forth in right ascension we found nothing. We took the scope back to Dubhe using the setting circles and it was still correctly aligned so we tried to use the circles to find Phad.

Looking in the scope I found that we were not quite aligned properly and manually aligned Phad in the main view. Looking back at the setting circles it appeared that we were out by one degree in declination. We then brought the scope over to the coordinates for M81 and added one degree to the declination scale and offsetting for the 20 minutes of right ascension that had elapsed since we began the hunt. I swept along right ascension and suddenly there they were. M81 at the bottom of the view and M82 at the top.

It was difficult to see any detail in M81 and it did not suffer magnification too well. We achieved a nice view of it at 112.5x magnification but it became very dim at 225x. The story was the same for M82 so we settled for 112.5x magnification and scrolled back and forth between the two galaxies with a twist of the declination knob enjoying a view which had been travelling to us for a mind boggling 12 million years.

An unforgettable evening and our first galaxies!

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