First Light with the Tele Vue DeLite 7mm

12 March 2020, 19:30 – 21:45

Conditions: A chilly night (after a few mild days) with frequent strong gusts of wind (again). With the moon due to rise between 21:30 and 22:00, I had a roughly two-hour window to field-test my new acquisition: a Tele Vue 7mm DeLite. In the XT10 the DeLite gives a magnification of 171x, neatly filling the gap between the 9mm Nagler (133x) and the 5mm Nagler (240x).

Seeing: Poor to average
Transparency: Average to poor

The tube currents took a while to settle down, but once they did I turned my attention to:

NGC 2392, Eskimo Nebula, Gemini
At 171x the Eskimo was bright and nicely framed, with the central star clearly resolved as a tiny pin-prick of light. (It’s sometimes hard to separate the star from the nebula at other magnifications, but this eyepiece seems to hit the sweet spot.) There was even a hint of brightness variation in the outer shell of the nebula, but the variable seeing made this elusive.

h3945, double star, Canis Major
Viewed at 171x and 133x. I meant to look at this pairing last time out, but got distracted by NGC 2362. The seeing tonight was especially poor at this low altitude, but there was enough separation between the stars for it not to matter too much. h3945 (it deserves a catchier name) is a lovely double star comprised of a rich golden primary and a bright blue secondary (north). Some observers call it the Winter Albireo, and on this evidence I can see why.

Iota Cancri, double star, Cancer
Quite by chance (I was star-hopping to NGC 2683), the very next object I looked at was another colourful double, comprised of a pale yellow primary and a blue secondary (west). A very pretty pairing and another contender for the “Winter Albireo” label, but I think h3945 has the edge.

NGC 2683, galaxy, Lynx
Viewed at 133x and 171x. Bright, spindle-shaped galaxy aligned roughly NE-SW. Brighter towards the core, but no stellar nucleus as far as I could tell. Faint field stars across the eastern side of the galaxy. Dark cut-off along northern edge, indicative of a dust lane (like the one in NGC 7331).

NGC 3115, the Spindle Galaxy (Caldwell 53), Sextans
Follow-up from previous observation, viewed at 171x. Bright little galaxy, very bright towards the core. Much smoother outer envelope than 2683 (which seemed mottled by comparison).

M81 and M82, galaxy pair, Ursa Major
M81 was bright and large at 171x with a sprinkling of foreground field stars. Maybe a hint of spiral structure. I should really spend more time studying this galaxy, but it’s hard to concentrate on it when you know M82 is only a nudge of the scope away. Talking of which, M82 was also bright and large at 171x, with the main dark rift clearly visible, and a bright knot on the western side of the rift.

NGC 3077, galaxy, Ursa Major
An overlooked member of the M81 “family” (it’s taken me this long to get round to seeing it). Faint compared to M81 and M82, but not at all difficult in the DeLite. First impressions: an amorphous round blob near an 8th magnitude star; brighter towards the centre, but with a suggestion of asymmetry.

M40 (aka Winnecke 4), Ursa Major
An uninteresting pair of 9th magnitude stars – what more can I say about it? But I’ve seen it now (after many years of ignoring it), so let’s tick it off the list and move on. Fortunately M40 is en route (from Delta Ursa Majoris) to a much more worthy object…

NGC 4605, galaxy, Ursa Major
Faint, extended galaxy aligned roughly east-west. The DeLite showed a brighter bar-like core region which seemed to be at a slight angle to the rest of the galaxy. An intriguing object, made more interesting by the knowledge that it’s less than a degree away from the famous Hubble Deep Field.

NGC 4485 and NGC 4490, galaxy pair, Canes Venatici
Moonlight starting to interfere at this point, but both galaxies still clearly visible. The higher magnification and contrast of the DeLite showed a dark gap between the two galaxies, but 4490
was obviously distorted towards the smaller, fainter 4485.

M3, globular cluster, Canes Venatici
A little washed out by the rising moon, but still fairly well resolved. The dark lane on the eastern side (noted last time out) was more obvious at the higher magnification.

NGC 3242 (Caldwell 59), planetary nebula, Hydra
The so-called “Ghost of Jupiter”. I can’t say it looked anything like Jupiter, but it was brighter than I was expecting, and quite obvious despite interference from moonlight and obstructing foliage. Pale blue-green disc of light. Suggestion of darker core with averted vision, and apparent bright patch on southern edge, but detail elusive. Worth revisiting when it’s in a clear part of the sky.

Conclusions
While obviously not having the “wow” factor of a super-wide eyepiece like the Ethos, the renowned sharpness and contrast of the 7mm Delite should make it invaluable for detailed study of some of the showpiece DSOs where 133x is too little power and 240x is too much. (And, of course, I'm very much looking forward to viewing the moon through it.) I’ve never had a problem with the eye relief of the other eyepieces, but the extra 5mm of the DeLite does make a noticeable difference. It really is a very comfortable viewing experience. And the 62 degree field is ideal for sketching too if I ever get back into that dark art.

Nature note
The frog breeding season does seem to be over now, which is just as well because there’s barely room for any more frogspawn in the pond.

Stargazing on a Windy Winter Night

27 February 2020, 19:30 – 22:30

Conditions: A very cold night with frequent strong gusts of wind – scuppering my original plan to view some planetary nebulae at the highest magnification the seeing would allow. (I stayed at 133x with the Nagler 9mm for most of the session.) No condensation.

Seeing: Good
Transparency: Poor to Average

The stormy winter continues; this was the first properly clear night for an entire month. I was hoping the storms might drag some clear air behind them, but the transparency didn’t really improve until the last half-hour of the session – by which point the cold was already becoming too much for me.

As usual, I began with a look at M42 (at 133x), before moving to Rigel. The companion star was easily visible, although partially obstructed by an extra diffraction spike. (I think this must have been something to do with the scope cooling down; the spike wasn’t present when I looked at Regulus later in the session with the same eyepiece.)

Betelgeuse is gradually starting to brighten again, according to recent reports. To the naked eye it seemed at least as bright as neighbouring Bellatrix, maybe fractionally brighter. Through the eyepiece it had a lovely orange/tangerine hue, strikingly different from the blue-white of Rigel. The colour was so vivid it prompted me to revisit another colourful star…

Hind’s Crimson Star, aka R Leporis, carbon star in Lepus
Seemed fainter than when I last looked at it, though the conditions (and/or the neighbours’ lights) might have had something to do with this. At 133x the blood-red hue contrasted nicely with the deep orange of Betelgeuse.

NGC 2170, reflection nebula, Monoceros
I drew a blank on NGC 2149, but 2170 was just visible as a very faint misty patch surrounding a star. Needed averted vision to be sure of seeing it.

M48, open cluster, Hydra
As noted previously, rich cluster of bright stars. Less impressive at 133x than at 92x in the Ethos, although the higher magnification does reveal some fainter stars near the middle. Distinctive two-arm flattened “spiral” of stars winding out from the centre along a N-S axis.

NGC 2506 (Caldwell 54), open cluster, Monoceros
Rich, small, condensed cluster. Several stars resolved with direct vision, with an underlying haze of unresolved stars. I think this cluster would look quite good on a better night. Seemed to be a dark “rift” protruding into the cluster from the south, giving it a bi-lobed appearance, like a sycamore seed.

NGC 2539, open cluster, Puppis
Rich, heart-shaped cluster, immediately west of 5th magnitude 19 Puppis. Brighter, larger and looser than 2506.

M67, open cluster, Cancer
Very rich cluster, perfectly framed at 133x. Stars arranged in tight clumps.

NGC 2362, Tau Canis Majoris cluster (Caldwell 64), Canis Major
Couldn’t resist another look at this spectacular cluster. I think the Ethos gives an aesthetically superior view, but the higher magnification does make it easier to resolve some of the close doubles lying within. Definitely one of the prettiest clusters I’ve seen – like fireflies gathering around a brilliant light.

NGC 2903, galaxy, Leo
Somewhat faint tonight compared to previous observations, but it still surprises me that this galaxy didn’t even make the Caldwell list. Condensed core, extended outer haze. With prolonged observation it seemed to take on a mottled appearance, with dark patches either side of the core. No spiral structure visible tonight.

I also looked for the dwarf galaxy Leo 1 near Regulus, but couldn’t see it on this occasion. Maybe an occulting bar would help…

I then pushed the scope towards Canes Venatici and Ursa Major to look at some old favourites (M108, M97 and M51). Nothing to add to previous notes (M51 wasn’t yet high enough to show much structure), but at approximately 21:25 I noticed an unusually slow-moving satellite or other object of about 9th or 10th magnitude pass just south of M51 (in the 9mm Nagler field of view), travelling in a roughly south-east direction. I checked Stellarium the following day, but it didn’t show anything in the vicinity at that time. Space-junk? One of SpaceX’s mega-constellation satellites? I have a feeling I’m going to be seeing a lot more of this stuff.

NGC 3631, galaxy, Ursa Major
Faint, round galaxy, brighter towards centre. Vaguely mottled with averted vision.

NGC 3756, galaxy, Ursa Major
Small, faint, featureless galaxy near field star. (I assume it was this I saw and not the nearby NGC 3738.)

M109, galaxy, Ursa Major
Large, faint galaxy extended along SW-NE axis; brighter towards centre. Bright star off south-western edge; fainter one off opposite edge.

NGC 3953, galaxy, Ursa Major
Moderately bright galaxy, rivalling nearby M109. Somewhat brighter towards centre. Misty/ghostly outer envelope – swells with averted vision.

I finished off the session by taking a quick tour of some spring favourites with the Ethos 13mm (92x):

M51 was high enough now to show some structure in the form of dark “crescents” between the spiral arms, although the spiral arms themselves remained elusive.

M101 was easy to find in the Ethos, but less easy to see any kind of structure beyond the core. The longer I looked, the brighter it got, with the suggestion of an isolated misty patch east of the nucleus (NGC 5462?) – but that was right on the limit of visibility. If I spent several hours on this galaxy over multiple nights, I think I could probably tease out more detail, but do I really want to devote all that precious time to one object when there are so many other galaxies to look at? (The deep-sky observer's dilemma...)

M106 was bright and obvious, but less detailed at this magnification.

NGC 4449 was small and bright with the now-familiar bright diagonal bar quite obvious across the face of the galaxy.

NGC 4565: a distinctive needle of light; dark lane visible with averted vision.

M65/M66/NGC 3628 (the Leo Triplet): M65 and M66 are well framed in the Ethos. NGC 3628 was significantly fainter, but not too difficult as galaxies go. The dark dust lane was visible with averted vision and was noticeably broader than the one running through 4565.

M3 was easy to find for once (thanks to the 9x50 finder). In the Ethos it appeared as a finely resolved ball of stars, with a very distinctive aquamarine tinge – backing up an observation I made last year with the 9mm Nagler. I think it’s easier to study this globular at the higher magnification, but the superfine detail in the Ethos was a sight to behold (it’s certainly something you’ll never see in a photograph). There seemed to be a dark lane on the eastern side of the cluster, giving it a vaguely squared-off appearance.

NGC 3115, the Spindle Galaxy (Caldwell 53), Sextans
This showed up as a bright little streak of light (one of the brightest galaxies I looked at tonight), well deserving of its nickname. Very bright towards the centre. For some reason I was sure I’d seen this galaxy before, but I can’t find any mention of it in my records (With hindsight I think I might have been confusing it with the similarly shaped NGC 2683 in Lynx). Definitely worth revisiting at a higher magnification.

Nature note:
After a couple of weeks of frenetic splashing, the frog breeding season seems to have been suspended, leaving a large clump of frogspawn at one end of the pond. But there may be more to come: torchlight revealed several large frogs lurking deeper in the water.

The Tao of Tau Canis Majoris

28 January 2020, 21:30 – 23:30

A cold, breezy night. My feet felt frozen by the end of the session despite two layers of socks. Some hazy bands of cloud moving slowly from the south-west from about 23:15 onwards. But no condensation for a change.

Seeing: Average
Transparency: Good to Average

I started with a tour of some old favourites using the Panoptic 24mm (50x), before switching to higher magnification once the scope had cooled to ambient temperature and my eyes had dark-adjusted.

M42, The Orion Nebula
Viewed at 50x and 133x, both with and without the OIII filter. Not much I can add to previous descriptions; with the filter in place the nebulosity almost overwhelmed the Trapezium, particularly at the lower magnification. The OIII also imparted a strong green colour, more so than any other object I’ve used it on.

NGC 2392, Eskimo Nebula, Gemini
Showed up nicely at 92x (13mm Ethos). Bright shell and central star seen with direct vision; double shell with averted vision. Pale blue colour.

NGC 2420, open cluster, Gemini
At 92x appeared as a condensed fuzz of stars, about a dozen resolved with direct vision – more with averted vision. Lines of stars appear to curl out to four “corner” stars, giving the cluster a shape resembling a Mermaid’s Purse.

NGC 2355, open cluster, Gemini
92x. Another condensed group of faint stars. Brightest member on southern edge. Curving chain of stars leading north to brighter star. Pretty cluster!

NGC 2395, open cluster, Gemini
92x. Kite-shaped cluster of stars. Sparse, loose; not as good as 2355.

M50, open cluster, Monoceros
92x. As noted previously: rich, large. Prominent red star on southern edge of cluster.

NGC 2335, open cluster, Monoceros
92x. Small, sparse cluster, but there seemed to be an underlying haze of unresolved stars.

NGC 2343, open cluster, Monoceros
92x. Small and sparse again, but brighter stars than 2335. Roughly triangular in shape.

W Canis Majoris, carbon star, Canis Major
92x. Scarlet-hued star; distinctive, but not as vivid as Hind’s Crimson Star.

NGC 2353, open cluster, Monoceros
92x. Rich, if sprawling cluster, gathered around a bright 6th magnitude star (apparently a foreground star rather than a cluster member).

NGC 2362, Tau Canis Majoris cluster (Caldwell 64), Canis Major
92x. In a word: wow! I’ve never seen a cluster quite like this before. A stunning sight in the Ethos despite its very low altitude (declination -25 degrees). A brilliant 4-5 magnitude star (Tau) surrounded by a rich swarm of bright stars. Tau (which apparently is a member and not a foreground star) has a faint companion a few arcseconds east. The cluster has a roughly triangular shape, with another bright star further to the east. It almost looks too good to be true, like it was designed by a VFX artist for a sci-fi film. The highlight of the night.

NGC 2354, open cluster, Canis Major
92x. Loose, filmy mass of stars somewhat washed out by light pollution. Would no doubt be more impressive if it were higher in the sky (and not so near to NGC 2362).

NGC 2360, open cluster, Canis Major
(Caldwell 58) 92x. As previous description. Rich, straggly cluster of moderately bright stars.

NGC 2359, “Thor’s Helmet”, emission nebula, Canis Major
Ethos 13mm + OIII filter. I remember seeing a colour photo of this nebula in an astronomy book when I was a kid, and I was struck by how dramatic it looked: like a spectral demon charging headlong through the heavens. It’s an image that has stayed with me (particularly when I read the epigraph of JG Ballard’s story The Illuminated Man), but I never imagined I would get to see this nebula with my own eyes. For some reason I thought it was only visible from the southern hemisphere (curiously, O’Meara, in his book The Secret Deep, was under the same impression), but while planning my exploration of this part of the sky I realised that not only was its declination just -13 degrees, but also – crucially – it might be bright enough to see in the XT10.

I couldn’t see any nebulosity when I scanned the region unfiltered, but when I added the OIII it was immediately obvious, appearing as a bowl-shaped hemisphere of light with a short bright extension angling away from the southern end (one of the “horns” of the helmet). After staring at it (and to the side of it) for a little while I was able to see the other “horn” as a longer, fainter extension angling from the northern end, pointing west, as well as a bright spot on the northern edge of the bowl. Comparatively, NGC 2359 reminded me of a ghostlier version of the Crescent Nebula (NGC 6888 in Cygnus), another object which responds similarly well to filters, and is itself also powered by a Wolf-Rayet star.

It has to be said that telescopically NGC 2359 looked less like a spectral demon and more like a spectral cauliflower, but as nebulae go it was still very impressive. If NGC 2362 was the night’s highlight, this was a close second.

NGC 2438, planetary nebula, Puppis
With the OIII filter still in place I moved the scope across to NGC 2438, which would arguably be one of the winter’s best planetary nebulae even if it didn't share a telescopic field with M46. The OIII filter dimmed the surrounding starlight, thus making 2438 much more distinct, although it’s nowhere near as bright as the Eskimo Nebula in Gemini. On this occasion it looked a little like M57, appearing as a ring with a darker centre – although the dark core was smaller in size compared to the ring, giving the nebula a more donut-like appearance. Also the nebula seemed larger than it did on 17 January, though this was probably an illusory effect caused by the filter subduing M46.

NGC 2440, planetary nebula, Puppis
Small disc of light a few degrees south of 2438. A field star to the east helps confirm its status; otherwise I think it would be easy to overlook, particularly at low magnification. A close double star to the southeast can also distract the unwary observer. Very bright in the OIII filter; direct vision suggested a bright core and averted vision suggested a faint outer halo, but my eyes were getting very tired by this stage so it was hard to be sure. One to revisit at higher magnification.

Nature note
One frog in the pond (the usual long-stayer), plus lots of wriggling insect larvae.