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.
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