Galaxies in Canes Venatici

31 March 2019, 21:15 – 00:15 BST

A windy, slightly chilly night with occasional strong gusts (so unsuitable for imaging). A few small clouds scudding quickly across the sky. Transparency better than Thursday, but still nowhere near as good as the memorable session on 10 February.

All observations at 133x (9mm Nagler) unless otherwise stated.

Y Canum Venaticorum (La Superba), carbon star in Canes Venatici
Bright little red-hued star, like a glowing ember. I think descriptions of the colours of stars are sometimes overstated – particularly when there isn’t a nearby companion to contrast it with – but this one was very distinctive. A refreshing starter before I got into the main course of galaxies.

M63, Sunflower Galaxy in Canes Venatici
Stellar core; extended, mottled envelope. Two bright stars to the west, a close grouping of three fainter ones to the east.

M94, galaxy in Canes Venatici
Bright core with a circular extended envelope (brighter overall than M63). On first impression it might be mistaken for an unresolved globular cluster, or the Eskimo Nebula (2392) with an additional shell of nebulosity. One bright star some distance west of the galaxy.

NGC 4490/4485, interacting galaxies in Canes Venatici
Elliptical misty patch with smaller, fainter companion, like two fish circling each other.

NGC 4449, irregular galaxy in Canes Venatici
Following on from Thursday's observation – boxy shape, grainy texture. Averted vision appeared to show three “knots” or condensations arranged in a line, the middle one being the brightest. Increasing the magnification to 240x (5mm Nagler) suggested dark mottling and bays around the edge of the galaxy. Also a brighter central bar running diagonally across the face of the galaxy. Averted vision at this magnification showed a bright spot on the eastern corner – hard to tell if this was another condensation or a foreground star. I wish more galaxies showed this much detail.

M106, galaxy in Canes Venatici
Viewing at 240x showed a large bright core and a shallow s-shaped spiral – the northern arm was easier to see. Averted vision seemed to suggest a dark area just north of the nucleus. Switching back to 133x and sweeping around the area revealed a couple of neighbouring galaxies:

NGC 4346, galaxy in Canes Venatici
Roughly due east of M106, with a bright star midway between the two. Elliptical fuzzball with a stellar core.

NGC 4220, galaxy in Canes Venatici
Roughly northwest of M106. Small and faint spindle of light.

M51, Whirlpool Galaxy in Canes Venatici (with NGC 5195)
Tonight the two galaxies had an almost ghostly aspect about them; the spiral arms seemed to fade in and out of existence independently of averted vision. The view wasn’t substantially improved at 240x, other than highlighting some of the brighter areas with a milky glow. The sketch above (compiled from observations carried out over three separate nights) gives an impression of what you can see with careful, prolonged study - even if you don't have the darkest skies (or the largest telescope).

NGC 5005, galaxy in Canes Venatici
Small, but fairly bright galaxy. It’s hard to be sure of detail when you’re looking at an object for the first time, but there seemed to be a suggestion of an inclined spiral and possibly a bar running through the core.

NGC 5033, galaxy in Canes Venatici
Southwest of NGC 5005; similar size but fainter. Stellar nucleus.

A detour “across the border” for two showpiece galaxies:

M101, Pinwheel Galaxy in Ursa Major
Large, low surface brightness. Very subtle S-spiral hinted with averted vision (needs exceptional conditions and/or an Ethos to get the best out of this galaxy, I think). Field star superposed on face of galaxy, north of nucleus.

NGC 5907, Splinter Galaxy in Draco
Faint, very narrow edge-on galaxy, well deserving of its nickname. Quite impressive with averted vision. Faint star west of nucleus.

And back to the southern region of Canes Venatici and beyond:

NGC 4631, Whale Galaxy in Canes Venatici
Large, “fat” galaxy (particularly compared to 5907). Foreground star on northern edge of galaxy near centre (I can’t really call it a nucleus) and a very faint blur just beyond that – fleetingly visible with averted vision (confirmed later as the dwarf companion NGC 4627 “the Pup”).

NGC 4656, Hockey Stick Galaxy in Canes Venatici
Faint streak of light southeast of 4631. No condensations that I could see, but one half of the galaxy is brighter than the other, with brighter areas towards the centre and one end (corresponding with the “hook”).

NGC 4559, galaxy in Coma Berenices
An overdue first look at number 36 in the Caldwell list. First impressions: large irregular blur, brighter towards core, but not condensed. Southern side of galaxy framed by three stars of varying brightness.

As Hercules was rising in the northeast, I rounded off the session with a look at two of the northern sky’s best globular clusters.

M92, globular cluster in Hercules
As per previous observation from last year: rich, bright condensed, well resolved. Slight oval shape – not circular. Bluish tinge?

M13, globular cluster in Hercules
Large and “sprawling” compared to M92, not as condensed. Very well resolved. Couldn’t be certain of seeing the dark “propeller” feature, but I did see NGC 6207 for the first time: visible as a small, faint lens-shaped galaxy with a stellar nucleus (I later found out that this is actually a foreground star). As is often the case with these objects, it seems obvious now I know where to find it.

Nature note: heard two foxes screeching at each other a couple of streets away. One frog in the pond (the tadpoles seemed to be purposefully avoiding it).