Sunday, 25 April 2021

More Spring Galaxies (Leo Minor to Boötes)

​6 April 2021, 21:30 – 00:30 (BST)


Seeing: Good 

Transparency: Average / good

Another very cold, gusty night, with another brief snow flurry during the day. Patchy clouds blowing south again (more so than the previous night). No condensation.

I started the session by revisiting Ursa Major’s two “Alula” doubles, but at a higher magnification.

Nu Ursae Majoris (Alula Borealis)
171x. As per last night: Pale yellow-orange primary and a faint secondary south. Oddly, despite there being a more comfortable gap between the two stars at this magnification, the secondary seemed fainter tonight.

Xi Ursae Majoris (Alula Australis)
171x. A paper-thin but clear split at this magnification. Two almost identical yellow-white stars; primary north, secondary south.

NGC 3430, galaxy, Leo Minor
133x. Very faint, amorphous patch of light; gradually brighter towards the centre with averted vision. This is the most prominent of a group of galaxies in the same small patch of sky, but only this one and NGC 3395 are plotted in the PSA.

NGC 3395 and 3396, interacting galaxies, Leo Minor
133x. Faint pair of galaxies angled towards each other, like a smaller, fainter version of NGC 4567/4568 in Virgo. The western one (NGC 3395) seemed slightly bigger and brighter. Averted vision suggested star-like cores in both galaxies.

NGC 3413, galaxy, Leo Minor
133x. (Plotted in SA 2000). Super faint smear of light, aligned north-south. Only visible with averted vision.

At this point the clouds were becoming larger and more frequent (blowing to the southeast), so I had to keep hopping from one clear patch of the sky to the next to stay ahead of them.

NGC 3242 “Ghost of Jupiter” (Caldwell 59), planetary nebula, Hydra
133x. Bright blue-green oval of light (seemed especially vivid after those faint galaxies). Appeared brighter on the northwest side. Similar impression at 171x, but less intense and softer-edged. Suggestion of darker core with averted vision.

65 Ursae Majoris
171x. Lovely triple star system; good split at this magnification. Two close stars with a more distant one trailing to the east.

NGC 4111, galaxy, Canes Venatici
171x. Bright streak of light with a bright core (as per last night).

NGC 4138, galaxy, Canes Venatici
171x. Faint round haze south of a field star. Brighter towards centre with averted vision.

I couldn’t locate the other galaxy (NGC 4143) plotted near here, so I spent the next few minutes revisiting some old favourites: M3 (showing a lot more stars at 171x), NGC 4565 (171x and 133x) and M51 at 133x. M51’s structure was visible with a little effort, but it looked more like a ring than a spiral tonight.

NGC 2300, galaxy, Cepheus
133x. One of the most northerly DSOs visible in my scope. Appeared as a small, condensed galaxy; bright core with averted vision. While using averted vision I had the impression of a larger, fainter galaxy above it (confirmed as NGC 2276), near a bright field star. 

NGC 2268, galaxy, Camelopardalis
133x. Very faint oval haze. Increased in size with averted vision, which also revealed a small bright core.

NGC 5448, galaxy, Ursa Major
133x. Very faint streak of light, a little brighter towards the centre with averted vision. Almost disappeared in direct vision. Located in the southeastern corner of Ursa Major, east of Alkaid.

NGC 5676, galaxy, Boötes
133x. Large faint oval galaxy, gradually brighter towards the centre with averted vision. The most prominent member of a small gathering of galaxies in northern Boötes.

NGC 5689, galaxy, Boötes
133x. Faint streak of light – lens-shaped or edge-on; smaller than NGC 5676. Stellar core with averted vision.

IC 1029, galaxy, Boötes
133x. Very faint streak of light west of a field star. Like a ghost of NGC 5689, but rotated 90 degrees. Brighter star-like core with averted vision. Located about half a degree from NGC 5676. 

NGC 5631, galaxy, Ursa Major
133x. Conspicuous round oval haze in a sparse star-field. Condensed stellar core with averted vision.

I couldn’t find nearby NGC 5585 (I think galaxy fatigue was setting in), but I did see a dramatic multiple star system west of its location (Struve 1831). I didn’t want to finish the night on a blank, so I tracked down one last galaxy just over the border in Draco:

NGC 5678, galaxy, Draco
133x. Slim oval smudge of light flanked by two field stars. Only very slightly brighter towards the centre with averted vision. Nice pale orange and blue double star due east (Struve 1872?).

Nature note: 
Aside from a fox barking in the distance and two cats fighting out the front, it was very quiet again.

Sunday, 18 April 2021

Spring Galaxies (Ursa Major to Corvus)

5 April 2021, 21:30 – 00:30 (BST)


Seeing: Average

Transparency: Average / good

A very cold night for April (there was even a light shower of sleet and snow during the day), with a strong gusty wind blowing from the north. No surprise then that I was wearing full winter gear, but at least the grass was dry and relatively mud-free. As I wanted to minimise the time spent taking my gloves on and off, I stuck with just one eyepiece for the entire session: the 13mm Ethos (a proven galaxy catcher) at 92x.

While my eyes were still dark-adapting, I warmed up with a couple of double stars in Ursa Major:

Nu Ursae Majoris (Alula Borealis)
Pale yellow-orange primary with a faint (possibly blue) secondary quite close to the south (10th magnitude at 7 arcseconds). A third (presumably unrelated) star nearby. An attractive sight to begin the session.

Xi Ursae Majoris (Alula Australis)
White “elongated” star, like a filled-in “8”. Not quite resolved at 92x, but enough to tell it’s a double.

At this point, while glancing away from the scope, I spotted two meteors. The first one (at approx. 21:45) passed through Sextans, heading southwest. About five minutes later another one flashed high overhead through Auriga, heading west. The second one was very bright, although not bright enough to leave a trail or be classed as a fireball. 

On a less interesting note, the sky was crawling with satellites tonight, though I suppose we’re entering that time of year when they’re visible for longer.

M81, galaxy, Ursa Major
For once I didn’t allow myself to get distracted by M82 and, after a while, there was a suggestion of a hazy extended halo, doubling the size of the galaxy. The spiral arms themselves remained elusive, but the haze on the eastern side seemed slightly more prominent, separated from the core by a darker area. The effect was so subtle I can’t really count it as a positive identification of spiral structure, but it does illustrate that most of the time when you’re looking at M81 through a small-to-medium scope, you’re really only seeing the galaxy’s innermost regions.

NGC 3079, galaxy, Ursa Major
Rather faint streak of light aligned roughly north-south. Somewhat brighter towards the centre with averted vision. Similar size to M82. Also: colourful orange / yellow-white double star in same field to east.

NGC 3432, galaxy, Leo Minor
Long, very faint streak of light aligned roughly NE-SW between two field stars. At least three faint field stars superposed over the galaxy.

NGC 3294, galaxy, Leo Minor
Large oval blur, roughly aligned east-west. A little brighter towards the centre with averted vision.

NGC 3310, galaxy, Ursa Major
Small, bright round galaxy south of a bright star. Bright core with averted vision.

NGC 3631, galaxy, Ursa Major
Large, round and diffuse; bright core with averted vision. Suggestion of asymmetry in the halo – I’m guessing this is a spiral galaxy. Also: a bright double star to the southwest.

NGC 3938, galaxy, Ursa Major
Another large round blur, gradually brighter towards the centre. Again, like 3631, a very vague suggestion of spiral structure – seemed brighter on the eastern side. This galaxy is a long way from any useful field-stars, making it tough to find via star-hopping.

NGC 4051, galaxy, Ursa Major
Amorphous round fuzz east of a field star. Star-like nucleus with averted vision.

NGC 4013, galaxy, Ursa Major
Small, lens-shaped streak of light aligned NE-SW. At first glance it appears to have an intense star-like nucleus glinting like a diamond, but I strongly suspect this is a foreground star. (Subsequently confirmed when I looked up the spectacular Hubble image of this galaxy.)

NGC 4111, galaxy, Canes Venatici
An oval smudge of light just over the border from Ursa Major. Bright core with averted vision; another double star to the north.

Next, a detour to Coma Berenices for one new galaxy and one old favourite:

NGC 4494, galaxy, Coma Berenices
Round fuzz ball near the Coma Star Cluster (Melotte 111). Bright core, stellar nucleus; looks a lot like a stray elliptical from the Virgo Cluster. Surprised I haven’t seen this one before, but there is a very distracting galaxy nearby…

NGC 4565, Needle Galaxy, Coma Berenices
Beautiful edge-on galaxy, a spring favourite. Dark dust lane visible with averted vision, becoming harder to see the farther it extends either side of the core. Field star NE of the core.

This was followed with a few more favourites in the shape of M101 and M51 and a quick trek along Markarian’s Chain in Virgo. I’ve had better views of these galaxies before so didn’t take any notes on this occasion. At this point the constellation of Corvus was emerging from behind the neighbour’s tree, so I made my annual attempt to track down the Antennae galaxies…

NGC 4038 and 4039 (Caldwell 60 & 61), interacting galaxies, Corvus
With the exception of M83, spotting galaxies south of about -15 degrees declination is a real challenge from my location. But after carefully sweeping north-northeast of 5th magnitude 31 Corvi I spotted an extremely faint glow within an upside-down y-shaped asterism of stars. With time and averted vision the glow took on a vague shrimp-like appearance, with the northern component looking slightly brighter. I made a rough sketch of the field just to make sure I wasn’t imagining it. Of course, the famous tidal tails would be beyond the reach of my telescope even if the galaxies were overhead, but I was pleased to confirm that the view tallied pretty well with Phil Harrington’s sketch on his challenge page , albeit much, much fainter.

I rounded off the session with quick looks at the globular clusters M5, M3 and M13. Compared to the other two with their tightly condensed cores, M13 looked like a bonbon coated with sugar crystals. (It was late; I was ready for chocolate.)

Tuesday, 13 April 2021

A Lunar Interlude

22 March, 18:30 – 20:00 

Technically not a deep-sky post, but with the Moon just past first quarter and about as high in the sky as it can get, there's no better time to observe our nearest neighbour. Highlights included the familiar Straight Wall plus the nearby Rima Birt. Another rille was visible inside the rim of the crater Pitatus, as well as a section of the Hesiodus rille (showing a distinctly flat floor). The full extent of the Hadley rille was visible (always an indicator of good seeing) – enabling me to pinpoint the Apollo 15 landing site. Lots of fine detail in and around the Fra Mauro region. Copernicus looming on the terminator (rim illuminated, interior shadowed) with super-fine detail in the surrounding ejecta pattern. This was one of those rare occasions where I used all five Tele Vue eyepieces, although the seeing wasn’t quite good enough to warrant going above 240x with the Powermate.

I also tried Sirius again (this time in deepening twilight, after seeing a tip on Cloudy Nights), but there was still no sign of the Pup. I think the main problem I have is that when Sirius is at its highest altitude from my location, the diffraction spikes from the secondary mirror are always going to obstruct the view of Sirius B.


Nature note:

The dunnock was singing sporadically again, but the most notable observation of the evening was the sheer number of birds seen silhouetted against the moon: waves and waves of them, mostly flying east – and at a very high altitude. The sky was still somewhat blue when I first noticed them through the eyepiece, but they were invisible to the naked eye. It was very difficult to tell exactly what they were, but I would guess they were winter thrushes (fieldfares, redwings) returning to their breeding grounds.


23 March, 19:00 – 20:00

The seeing was even better tonight (although it tailed off steadily once the Moon crossed the meridian). Observations carried out at 171x (DeLite 7mm), 333x (Nagler 9mm + 2.5x Powermate) and 428x (DeLite 7mm + 2.5x Powermate).

Highlights: The three largest Plato craterlets were resolved as actual craters, as opposed to white spots. I couldn’t see the rille in Vallis Alpes, though after reading up on it later I realised I’d underestimated just how narrow it is relative to the valley. Wealth of detail in and around Copernicus – easily the best view I’ve ever had of it. Wrinkle ridges in Mare Imbrium. Cape Laplace (on the edge of Sinus Iridum) casting a very long shadow.

Moving south to Mare Nubium: The rest of the Hesiodus rille was now visible. The concentric crater structure of Hesiodus A was showing very well. Dome visible in Capuanus crater. Ramsden rilles showing really well (reminiscent of the Triesnecker complex). Hippalus rilles (from Mare Humorum) near the terminator.

Also worthy of mention: A very bright ISS pass at 19:30, moving high over the Moon and almost touching Pollux in Gemini. While this was going on I also noticed an extremely bright flare in the east from another object which looked to be travelling on a similar orbit to the ISS, roughly 90 degrees ahead of it. I haven’t yet been able to determine what it was. Stellarium plots several satellites passing through that area around that time (including a few of the ubiquitous Starlinks), but none of them appear to be related to the ISS.

Nature note: 

Still a few birds flying across the face of the Moon, but not nearly as many as the previous evening.


Friday, 2 April 2021

Nebulae in Monoceros

15 March 2021, 19:45 – 22:30


Seeing: Average / Poor

Transparency: Average (cloud permitting)

A cool evening (after a mild day) with bands of high, hazy cloud drifting across the sky. Very light condensation on the telescope tube. The gentle breeze was a welcome change after a run of very blustery weather over the last few days. 

With the nights getting shorter and a new lunar cycle already underway, this was probably my last opportunity for a while to explore the winter Milky Way, so I started at low power (50x) with the 24mm Panoptic, plus the OIII filter to pick out some nebulae. When using this filter you have to cup your hands around the eyepiece to get the best out of it, as it does tend to reflect stray light bouncing off your eyeball. (I’ve noticed this before, but tonight it was more prominent than usual, particularly on the right hand side of the field of view.)


NGC 2359, “Thor’s Helmet”, emission nebula, Canis Major
50x + OIII filter. The nebula showed up clearly with this eyepiece/filter combination, but only the brightest sections were visible tonight. Averted vision showed a bright spot on the northern part of the nebula.

The area northwest of NGC 2359 is rich in nebulae according to every chart I’ve seen, but nothing obvious jumped out at me when I scanned this region. Pushing on into Monoceros, I arrived at…

NGC 2237-9, Rosette Nebula, Monoceros
50x + OIII filter. Visible as a very large, structureless haze surrounding open cluster NGC 2244. The nebula appeared widest and brightest on the north and west sides.

After sweeping north, to the Christmas Tree cluster, and then west, I stumbled upon something I hadn’t seen before:

NGC 2245, reflection nebula, Monoceros
50x + OIII filter. Although catalogued as a reflection nebula (I didn’t know this at the time, as the chart doesn’t make a distinction between reflection and emission nebulae), it showed up very clearly as a small, fuzzy patch of light immediately southwest of a bright 8th magnitude star. Averted vision showed it to have a bright core. Increasing the magnification to 171x (no filter) improved the view considerably: now I could see an 11th magnitude star embedded in a wide, comet-shaped swathe of nebulosity fanning out to the southwest. Reminiscent of nearby NGC 2261 (Hubble’s Variable Nebula) but with a curved rather than a pointy apex. There was a hint of similar (albeit fainter) nebulosity corresponding with the position of nearby NGC 2247, but some hazy cloud pushed in before I could confirm it.

Relocating to a cloud-free (for now) part of the sky:

M97, Owl Nebula, Ursa Major
50x + OIII filter. Viewed at low power with an OIII filter, the Owl Nebula actually looked “bright” for once, appearing as a round, soft-edged disc of light. At 171x (no filter), it was faint, but the dark “eyes” were just about visible.

NGC 3893, galaxy, Ursa Major
171x. Follow-up from the previous session. At this magnification the companion galaxy (NGC 3896) was visible with averted vision as a small, faint patch of light roughly east of the main galaxy, and adjacent to a 13th magnitude field star. Together, the two galaxies resembled a subdued version of the Whirlpool Galaxy (M51) and its neighbour as seen through a small telescope. Magnification makes the difference on this one; NGC 3896 was much harder to distinguish from the 13th magnitude star when I dropped down to 92x.

NGC 3166 and 3169, interacting galaxies, Sextans
92x. Pair of small oval galaxies in same field of view, separated by a few arcminutes. Similar in size, but the western galaxy (NGC 3166) has a much brighter core. The other galaxy (NGC 3169) is just west of an 11th magnitude field star.

With more clouds pushing across the sky from the west, I called it a night.