Meade Lightbridge Observing report as of 23.3.2009

[Doc]

23.3.2009

Meade Lightbridge 16" FL 1829mm F4.5

No Moon.

Very Windy

Seeing Mag 4.5

Started off viewing the International Space Station at 18.39. The sky was still light and the ISS was shining at a mag of -2.0 as it went across the sky West to East. Very pretty sight.

I then aimed the scope towards Saturn. Wow as always I'm totally gobsmacked by the beauty. Saw 4 moons Titan at 8.3, Tethys at 10.2, Rhea at 9.7 and a long way out lapetus at 11.1 mag. Best view was in my Baader Hyperion at x87. I could clearly see two bands as well.

Next was the M51 in Canes Venatici I've tried quite a few times to find this galaxy, considering it is named "The Great Spiral Galaxy" I always find it hard to find but this time I set up the

Wixey and found it quite easily. I must admit I expected more but a darker site would definetly help. What I saw in my 25mm TAL at x74 mag was a very dim circular smudge of grey and could clearly make out another little smudge just to the side of it. This is of course NGC5195. I then tried the Baader Hyperion 21mm and this did improve the view slightly but higher mags just made the view worse. No spiral or dust lanes could be made out, but at least I saw it.

By now the wind had really picked up and was moving the scope slightly. But we don't get many clear nights so I carried on.

Next over to Gemini and the little planetary Nebula NGC2392 also known as the Eskimo, or Clown Face Nebula. Quite easy to find despite it's size of only 0.8'x0.7' in the 32mm TAL at x 57 and looked like a little star but the thing I really noticed was how it pulsated. Up the mag to x87 and you could clearly see a blue tinted non stellar shape that pulsated with good seeing. Also noted a lot of stars in the same FOV that made this view very pleasing indeed.

By now it was 20.14 so was time for the next fly past by the ISS. I decided to track this with my dob. No easy task but managed it quite successfully. In the 21mm Hyperion I could clearly make out the ISS shape. Pretty impressive I thought.

Back over to Saturn as it was now getting higher. The moons had moved a fair bit but I did manage to bag Encelade at 11.7 mag with my 9mm ortho at x203. And at times of good seeing I might have bagged Dione at mag 10.4 but this was very close to Saturn and I'm not 100%. Apparently Mimas was transiting Saturn at this time but I couldn't see it. So I saw 5 moons and maybe 6.

By now the wind was getting stronger so I could it a night. Shame as the seeing was pretty good.

[red dwalf]

managed alot more than me i`m affraid, got a good luck at Saturn again, one of the moons was really bright, but far to cold and breezy for me

[jarbi]

Nice report Doc, I wish I could use my LB 16" also ( the secondary must be replaced because of astigmatism... ). Hopefully I can start with it next week.

cheers,

Janos

[Doc]

Nice report Doc, I wish I could use my LB 16" also ( the secondary must be replaced because of astigmatism... ). Hopefully I can start with it next week.

cheers,

Janos

What a shame Janos.

I never knew, tell me what happened.

[acey]

Nice report, sounds like a good session. Interested by the pulsating Eskimo - I assume you mean the way its apparent brightness changed as your eye moved, so that you alternate between direct and averted vision. Or maybe it's started doing something new since I looked at it the other night...

4.5 is my back garden magnitude - I drive to a mag 6 site and get a much better view. Have you considered transporting the scope? Spiral arms of M51 will become easy. The magnitude difference of 1.5 is equal to an aperture factor of 2: you're currently seeing what would be visible with an 8" at a dark site. Or putting it another way, your scope at a dark site would show you what a 32" would achieve at your present one!

Andrew

[Doc]

Cheers Andrew I know that I must take it to a dark site. Problem is the sheer size of it. Pretty daunting task, but I know that it would excell so much more.

Another problem is I haven't any filters for it yet. Still trying to save for them.

As for this "Pulsation", yes it did happened when my field of vision changed but also when I was looking straight at it. There is nothing else in that area it could be as it was definnetly not a star, you coulld see shape.

100% sure it was the Eskimo Neb.

[acey]

Hmm that's odd. I wonder if there might have been thin passing cloud that was causing a brightness variation, or even momentary misting of optics. Or maybe the "Clown" was getting up to some mischief!

[Talitha]

Congratulations on bagging the Whirlpool and its companion. They'll be easy to get from now on.

Wow, the Eskimo Neb is a real puzzler. I imagine the brightness increase/decrease was quite rhythmic since you mentioned pulsations... how long did you have it in the fov?

[Doc]

Carol I cannot explain it either.

I had to keep nudging the scope to keep it in my FOV. I looked at it maybe for 3 minutes in the 32mm and about the same in my 21mm.

In both eyepieces the brightness flutuated. The nebula was not always centered as I let id drift through my FOV with the occasional nudge.

There was a definite blue tint to the nebula

[jarbi]

What a shame Janos.

I never knew, tell me what happened.

When I was out the second time with the scope, all stars were elongated in focus . The out of focus images were perpendicular to each other on the two sides of focus. My further tests and the astroshop also confirmed that the secondary is the problem. Sent to Meade more than 2 weeks ago.. Hopefully a new one arrives this week. The mystical part of the story: there was no detectable astigmatism at "first light". No clue what happened in between .

cheers,

Janos

[Doc]

That is very strange Janos.

Well lets hope Meade sort it out for you.

[acey]

Astigmatism can arise in various ways - one is if the optics haven't cooled sufficiently, though you probably thought of that. Another is if the weight of the primary isn't sufficiently supported - I assume Meade thought of that in their design. Another is if the mirror is distorted by pressure (of clips etc). But it doesn't sound as though you'd removed and reassembled the optics. My old newt aquired an astigmatism I could never quite figure out which I guessed to be from the secondary (which was held in place by a clip) but which I couldn't solve. I think you're right - let Meade work it out. Good luck with it, and I hope you're observing again soon.

Andrew