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Old 07-01-2008, 03:03 PM
žAB
Its only a column of dust

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Obs Report 7/1/08 - Double stars, NGC 2440, 2808 etc

Oh yes, finally a cool night with promising seeing conditions. With minimal jetstream and a west/southwesterly surface airstream matching high altitude winds, the seeing was better than on previous nights with the northerly winds.

Set up my 10" reflector and at that moment a gorgeous deck of stratocrapulus moved in. Well I used the time to collimate and do other setting up. The cool temps, around 15║C, meant that there was not one mosquito or spider annoying me . The still calm air provided good seeing. The transparency was also better. Despite the ideal conditions, bloody stratocumulus clouds came and went, interrupting me throughout the night. This has wet my appetite for some nice crisp winter nights observing the Sagittarius starclouds and high power views of Jupiter overhead *drool*

Telescope: 10" GSO Dob
Seeing: 5-7/10
Transparency: 4/5
Temp: 15║C
Dew: No
Wind: No

NGC 362
Popped in the 5mm LVW for 250x. Got my best view of NGC 362 ever. It is indeed a gorgeous cluster! Resolved atleast 1/2 way to the core, with the remaining core regions sporting a nice granular appearance. Overlaying the cluster and surrounds are lovely arcs of brighter stars making it a pretty sight. Tried 500x, but heat currents radiating off my roof caused the view to tremble. So I backed it down to 250x again and enjoyed the view. Very nice!

Tarantula Nebula
Almost overhead, not above my roof. So what did I do? 3x Barlowed my 5mm LVW, that's what! Call me crazy but at 750x I could resolve more stars in the core than at 250x! A tight group of stars sits at the core of the nebula, and it is quite difficult to pick out the fainter ones at 250x. Using 750x, I could seperate all the stars nicely. I then popped in the TV 2x barlow for 500x and I was quite surprised by the crispness of the view. The stars weren't mushy, but rather like tight points. The core loomed huge at 750x, with numerous surrouned nebulae visible. One of the best views of the Tarantula I ever had.

Eta Orionis
Easy to find star, magnitude 3.4 with a 4.7 magnitude companion lying 1.7" away. Magnified it 625x, being a fairly bright star the atmospheric distortion was very obvious and intrusive. You could see the stars bouncing and vibrating like crazy! However, I could drive a train through the gap between the pair.

32 Orionis
A much more difficult object. The primary is mag 4.2 and companion is 5.6. They are seperated by only 1.1". Used 625x again, and the split was easy, despite the magnitude difference. Once again, the atmospheric distortion mangled the stars, but I could split it with my eyes closed!

NGC 2438
Starhopping to this Puppis Planetary Nebula at 56x is a wonderous experience. The starfields here are just spectacular! At 357x without filter, it was a thick, 'fluffy' smoky donut. The central area isnt quite dark. the NE edge appeared slightly brighter than the rest of the donut.

NGC 2440
Now this is an odd looking object! Tried a variety of mags. At 250x, it appeared to be a flatted semi-circle mesmerising in its brightness. The SE edge appeared brighter than the NW edge, with the part in the middle fainter and flattened, creating something that looks like a cross between a semi-circle and one side of a rectangle. The object is tiny so I increased magnification to 625x, which clarified it's strange shape. The intense core is surrounded by a haze (the bipolar lobe) elongated approximately NE-SW which is the material being blown off by the central star. I could detect a brighter area in the SW lobe just detached from the bright semi-circular region.

NGC 3918
I always thought this planetary was cool just from its perfect circular form and obvious greenish-blue colour. At 357x, it appeared as a fuzzy circular patch with uniform brightness.

NGC 2808
Globular cluster in Carina. Easily visible in the finder as a fuzzy 'star'. A 250x view revealed tiny pinpricks condensed towards the tight, almost stellar core. Increasing power to 500x bought a similar view, however the seeing appeared to be deteriorating and prefered the 250x view. Quite a lovely cluster. Due to its tightly packed faint stars, very good seeing would really bring out the best in this cluster.

Mars
Being perhaps 20║ above the horizon and just swimming in the seeing, I was hesitant. But my mum egged me on, wanting to take a look aswell. So I caved in, dropped in the 8mm LVW for 156x and pointed the scope at Mars. The eyepiece was so low that I had to hunch over in my chair to reach it. I was pleasantly surprised to see several dark features and a nice rusty orange colour that typifies Mars when seen in good conditions. I could also make out a polar cap Quite impressed!

Saturn
Nice and crisp at 156x, but the seeing was still obviously not quite up to par. Nevertheless, two cloud belts were nicely and sharply defined, as was the ring's shadow on the globe. The Cassini Division could be glimpsed at the ringtips. I also spotted a moon extremely close to the planet's limb, almost touching it.

By now it was past 3am and the clouds bought the knockout punch this time so I packed up.

A most fantastic night of observing looking forward to similar conditions tonight....will make the most of it before the heat returns
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Last edited by žAB; 07-01-2008 at 04:06 PM.
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Old 07-01-2008, 03:42 PM
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goober (Doug)
No obs, raising Harrison

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Mr. Magnification at it again - having handtracked a few dobs I don't know how you do it. I'll add 32 Ori to my list of doubles to chase down. 2440 is a planetary - how bright was it? I was heading out tonight - if the neighbours cooperate with their lighting, I'll hunt for it.
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Old 07-01-2008, 04:04 PM
žAB
Its only a column of dust

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Quote:
Originally Posted by goober View Post
Mr. Magnification at it again - having handtracked a few dobs I don't know how you do it. I'll add 32 Ori to my list of doubles to chase down. 2440 is a planetary - how bright was it? I was heading out tonight - if the neighbours cooperate with their lighting, I'll hunt for it.
hey Doug, it's actually a bright but tiny white semi-circular/squarish object at moderate-high powers. Looks like a fuzzy star at lower mags. Should be easy to pick out from the rich starfield as a fuzzy point. Good luck
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Old 07-01-2008, 04:38 PM
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goober (Doug)
No obs, raising Harrison

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Thanks - I'll have a go. My fine focus doodad turned up today, so I have incentive to install it and get out there. North, south and west look clear from here at 4:30pm!
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Old 07-01-2008, 05:09 PM
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goober (Doug)
No obs, raising Harrison

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I like the Tarantula sketch - I take it we're only seeing about 5 arc minutes of it?
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Old 07-01-2008, 07:01 PM
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edwardsdj (Doug)
Doug Edwards

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I like the Tarantula sketch too. One of my favourite objects
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Old 07-01-2008, 09:48 PM
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ngcles
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Hi žAB,

Again, very nice report. I particularly liked the sketch of NGC 2440 -- one of the most interesting PNe in the sky I reckon and your sketch looks remarkably similar to one I did about 15-odd years ago with my old 25cm on GEM at x290 with a lumicon UHC. The two spots in the centre are really intriguing. I'll see if I can find it over the next few days.

2440 changes again as aperture increases and there is an outer halo at a strange angle, visible in 46cm that it only hinted at in smaller apertures.

NGC 362 is another fav of mine too. I remember a night about 4 years ago when we were observing it using a friends 50cm f/5 and looking at NGC 362 in very good seeing that comfortably permitted full resolution within the inner core at x350 with pinpoint star-images, when we noticed a very tiny dark cross -- like a " + " sign dead centre of the cluster. Several of us saw it that night, but I have never seen it again like that. It was very small -- only about 5-odd arc-seconds across I think.

Anyone else with that aperture range seen that? I don't think even a 12" will show it because it won't (can't) resolve the tightly packed core so well.

Best,

Les D
Contributing Editor
AS&T
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