Showing posts with label neptune. Show all posts
Showing posts with label neptune. Show all posts

Tuesday, 17 December 2019

Finding Neptune

5 September 2019, 21:30 – 00:15 BST


Conditions: a near first-quarter moon low in the southeast ruled out observations in that part of the sky. A few small clouds passing overhead, air cooling noticeably, otherwise good for observing.

Albireo, double star, Cygnus
At 92x in the 13mm Ethos this presented as a golden primary and pale blue secondary suspended in a sea of stars. This might be the most beautiful view I’ve ever had of Albireo – certainly one worth savouring.

NGC 7027, planetary nebula, Cygnus
Revisiting one of last year’s targets. In the Ethos it resembled a defocused star. At 240x with the OIII filter it was very bright with a tantalising hint of structure. Quite small.

NGC 7039, open cluster, Cygnus
Looks good in the Ethos. A rich band of stars framed by a rhombus of brighter stars. Not far from the North America Nebula.

NGC 7048, planetary nebula, Cygnus
Just visible without the filter at 92x as a faint smudge of light with a star to the west. In the OIII it appeared as an elongated cone of light with a star at the apex. Unusual shape for a planetary nebula, but I think the star probably caused it to appear more distorted than it really is.

NGC 7000, North America Nebula, Cygnus
With the Ethos and the OIII filter, the “gulf coast” region of the nebula was clearly visible as a milky glow, resembling a large question-mark melting into the starry background. I didn’t think I’d be able to see it as well as this in the XT10.

M2, globular cluster, Aquarius
At 240x, the asymmetry noted before appears to be caused by two wings of stars sweeping back towards the west. The foreground star on the eastern side of the cluster seems to sit in its own pool of darkness, adding to the asymmetry. The cluster resolved really well with averted vision.

M15, globular cluster, Pegasus
Also observed at 240x. Member stars brighter than those of M2. Long loose “tail” of stars to north. Bright, dense core. The (rare) opportunity to view these globulars multiple times over the course of a fortnight really makes a difference – the more you look at them, the more you see.

Neptune 
Helpfully very close (maybe a little too close) to 4th magnitude Phi Aquarii, so (unlike last year) very easy to find. Viewed at 240x (5mm Nagler) and 333x (9mm Nagler + 2.5x Powermate). I need to try this again when the seeing is better, but Neptune was a tiny blue-grey disk (like a defocused star), contrasting nicely with the orangey-red Phi Aquarii. No sign of Triton.

M30, globular cluster, Capricornus
Small condensed blur, very low in the sky (-23 degrees declination). Bright leading star to west. Amazingly, with averted vision I could begin to resolve the cluster despite its low altitude: the most prominent features were a straight line of stars to the north and another fainter one (not radial to the core) to the northwest, giving the cluster a very distinctive lopsided, spiky appearance.

Just for fun, I also viewed M57 and M27 at 333x. Despite being on the light-polluted side of the meridian the Ring Nebula looked rather impressive at this high magnification (like a black-and-white photo); the Dumbbell not so much (it's large enough already that it doesn't really benefit from the extra power). But it's good to know I can use this magnification on some deepsky objects.


Tuesday, 21 May 2019

Galaxies and Ice Giants

4 October 2018, 21:45 – 00:00 BST


Conditions: The seeing was quite good but the sky was a little hazy, affecting the transparency.

NGC 7479, galaxy in Pegasus
Viewed at 133x (9mm Nagler): faint, extended streak of light with bright star at one end and a fainter one at the other. First impression - not unlike NGC 891. Sky transparency not good enough to see spiral arms, but suggestion of mottled structure along central axis.

NGC 404, Mirach’s Ghost, galaxy in Andromeda
Follow up observation at 240x (5mm Nagler). Showed up very well. High power made it easier to keep Mirach out of the field of view and to see more detail in the galaxy itself: condensed core and suggestion of nested structure rather than smooth gradation – arranged in two or three “shells” of brightness.

Neptune
Appeared as a blue “out of focus” star. The colour made it stand out from neighbouring stars. Hard to resolve, even at 240x. Two faint stars in vicinity.

Uranus
Obvious green-grey disc even at 133x. Clearly resolved at 240x – no detail or moons seen.

NGC 7331, spiral galaxy in Pegasus
Bright core, extended envelope, sharp cut-off on one side, indicative of dust lane. Very much like a smaller copy of M31. Could probably take 240x.

M74, spiral galaxy in Pisces
Faint, but still obvious despite its reputation as the toughest Messier. At 133x it showed a condensed core surrounded by a large faint disc. Hard to see any detail, but darker areas possibly indicating regions between spiral arms.

NGC 772, spiral galaxy in Aries
Small asymmetric patch of light, lacking same degree of condensation as M74. Seemingly irregular. My old notes tell me that I did see this with the Vixen 102, describing it as looking like a "ghost globular".

NGC 925, spiral galaxy in Triangulum
Extremely faint, amorphous patch of light. Could be easily overlooked if just sweeping through the area.

M33, spiral galaxy in Triangulum
Seemed positively bright compared to the previous three galaxies. One spiral arm clearly seen: clumpy patch of light curling from core towards a bright field star. The question remains (as with NGC 891) as to how much of this I would be able to see if I wasn’t already familiar with the photographic representation.

A quick look at the M31 satellite galaxies:
M32, Andromeda: star-like core.
M110, Andromeda: faint field star nearby perhaps matching location of globular? Maybe that's wishful thinking, but the G1 globular should just about be within my the range of my scope. Will need a detailed finder chart or photo to verify.

A quick look at two open clusters in Perseus:
NGC 1528 & NGC 1513: misty patches at 50x, partially resolved.

NGC 1664, open cluster in Auriga
Very distinctive cluster; stars form an outline resembling a kite or a stingray.

NGC 1579, emission nebula in Perseus
Very faint patch of light, possibly doubled. Somehow managed to lose track of it when I put in the Ultrablock. Though I might have been hampered by condensation.


Eventually the session was curtailed by condensation on the secondary mirror (although the primary remained dry). Could mean that I’ll be limited to two-hour sessions between now and spring.

Nature Note:
3 frogs in the pond: 1 big, 2 small.