Old 15-04-2008, 07:25 AM
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goober (Doug)
No obs, raising Harrison

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Join Date: Nov 2007
Location: Melbourne, Australia
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Observation Report: 14th April 2008

Location: Melbourne
Time: 2200 - 2345 EST
Conditions: cool, calm
Dew: medium
Seeing: Pickering 8
Transparency: very good (waxing quarter moon)

I was tossing out the garbage at 9:30 and looked up. Amazingly, the sky was clear with a day 8 moon shining down. I checked some stars for "twinkle", and the seeing looked very, very good. Another look at the moon and I thought "Plato!", and raced in to set up.

I only took out my 3-6mm zoom, my 5mm, and my new-but-old 1.8 barlow to test out. Nearly everything observed was with the 1.8x/5mm stack, giving me 192x and 25' FOV.

Moon - mainly concentrated on the Plato region. Began with the 5mm at 108x, and immediately spotted and held 2 craterlets. Never seen them so easily before with the 4". A combination of great seeing and better sun-angle I suspect. The moon may also be at perigee - not sure - but if it is, that certainly helps too. I popped in the barlow, despite freaking out that it would bottom out on my diagonal (it didn't, but it must have been close). The view held up well, albeit with only one craterlet now. It gave the moon a rather golden cast, rather than the crisp, contrast-y blacks and whites without the barlow.

Saturn - breathtaking view at 192x - crisp and steady. Two bands visible on the disk, Cassini division easily spotted at the edges of the rings, and texture in the ring bands. One of the best views of Saturn I've ever had.

Sirius - With seeing like this, it's time to split this bad boy. Nah, no luck. It's starting to lower in the west and I never seem to get good views looking in that direction. Bit of boil and bubble.

Algieba - double star in Leo, quite low in the north, just skimming the roof of my house. Lovely wide split at 192x. Beautiful golden pair.

Acrux - triple star in Crux, near the zenith. Primary stars were kissing at 192x, or at least the steady first diffraction rings were. The companion was a long way out. Beautiful view - everything was just sharp - no twinkle at all.

Mimosa - nice, although the nearby carbon star seemed to have dimmed since my last view. The magnification had also washed a lot of the crimson colour out at 192x.

Jewel Box - hopped over at 192x from Mimosa. The cluster filled the FOV, and looked so different at high power. The thing that struck me was how linear it looked - lines of stars running everywhere. I saw a medieval crown, with three jewelled points.

NGC 4833 - globular cluster in Musca. Located at 192x - large misty patch with around 20 stars resolved across the disk. Wasn't expecting much under the moon, but this was a pleasing view.

Omega Centauri - stunning at 192x, totally filling the field - couldn't count the number of stars I could resolve, but it must have been close to a hundred. Two dark patches were visible near the centre, one much larger than the other.

Centaurus A - with the moon washing everything out, and me still at 192x, I didn't hold out much hope for this one as I hopped over from Omega Centauri. However, I landed right on it, and it was quite clear and unmistakable. Transparency must be very good if this is visible under a quarter moon. Lane seen with averted vision.

M4 - globular cluster in Scorpius - had a bit of trouble finding this at 192x, so I wound it back to 108x and found it easily. Such a weird globular, with the spine of bright stars right across the core. Nice to welcome it back.

Graffias - double star in Scorpius. Very easy, bright double.

v Scorpii - double star in Scorpius - actually a triple star, I suspect. Bright primary, with the faint companion a tight double.

Antares - if Sirius defeated me, perhaps I could split Antares. Spent around 25 minutes on it. The image was rock steady at 192x - with steady, closed diffraction rings. Could not split it. I popped my 3-6mm zoom into my 2.5x Powermate and went stupid-high. The view held up well, but broke down at 385x. Couldn't split it. Bummer - great conditions too.

My table and atlas was soaked with dew, however the scope was holding up. I looked east for Jupiter but couldn't see it. Reluctantly packed up. If I didn't have to work, I'd have been out all night. Great conditions, too rare.
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Old 15-04-2008, 07:41 AM
Its only a column of dust

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Join Date: Aug 2007
Location: New Iceland
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A nice report yet again Doug.

Seeing was very good last night wasnt it? Only at the very beginning for me though, then quickly became poor. I can agree with your Saturn statement, was one of the best I had aswell. Never seen it so crisp at 240x in the 10".
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Old 15-04-2008, 09:55 AM
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Location: Melbourne
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It was a very good evening from the inner city; the seeing was a bit of a mixed bag, but the transparency was excellent. I turned on the fan & the tracking, parked the XW 7 in the 14" focuser (230x) & off I went. Spotted four craterlets in Plato - you can't beat a big, fast dob for lunar observing.

Saturn was a compelling sight too & the colours seemed more intense than usual - must have been the transparency.
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Old 20-04-2008, 09:48 AM
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Location: Billimari, NSW Central West
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Re: Your Report

Hi Doug,

Great report as usual mate.

You wrote:

"v Scorpii - double star in Scorpius - actually a triple star, I suspect. Bright primary, with the faint companion a tight double."

I assume you mean Nu Scorpii (14 Scorpii) near Beta. Nu is actually a really lovely "double-double" but a somewhat more difficut split than Epsilon Lyrae. I can't recall the splits at the moment but I use the tighter pair in winter as as a seeing test. From memory it is at about 1.1". The wider pair is much easier and the pair-to-pair split is quite do-able in binoculars. Really nice.

You wrote:

"M4 - globular cluster in Scorpius - had a bit of trouble finding this at 192x, so I wound it back to 108x and found it easily. Such a weird globular, with the spine of bright stars right across the core. Nice to welcome it back."

Indeed! The north-south spine of stars starts to become noticable from about 4" in aperture (the point where it begins to show _signifiicant_ resolution) and reaches its "distinctiveness peak" at about the 12-14" mark and from that point upward in aperture, it starts to get lost in more and more resolved stars. It is fading well and truly at 24" and by the time you get to 40", it is well and truly swamped by the other resolved stars. It is a lovely object.

The Herald-Bobroff serving you well?


Les D
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Old 20-04-2008, 09:59 AM
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Matty P (Matt)
Star Struck

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Location: Canberra
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Great report Doug, I always enjoy reading your observational reports.

Sounds like you had a rare night of great conditions. They don't happen very often, that's for sure.

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