Exploring the Virgo Cluster (Part 2)

22 March 2020, 21:00 – 23:45

Conditions: A very windy night with strong, frequent gusts. Quite cold too by the end of the session.

Seeing: Good
Transparency: Average

A challenging night’s observing to say the least, with star-charts threatening to take off in the wind and stray light encroaching from just about every direction (seriously, why don't people draw their damn blinds/curtains anymore?). All observations carried out at 92x magnification with the Ethos 13mm (it was too gusty to attempt anything higher and I really needed that huge field of view so I didn’t get completely lost). Finding a galaxy in the Virgo cluster is easy; the trick is knowing which galaxy you’re looking at.

Comet C/2019 Y4 (Atlas)
Found it at last, lurking very close to the red-hued star Rho Ursae Majoris. On first impression it looked much like one of the galaxies in the vicinity, albeit a little fainter than I was expecting. A stellar nucleus was visible with averted vision, at the centre of a large, extended coma. I couldn’t see any sign of a tail, but the light from Rho UMa made it hard to pick out any kind of structure.

With that out of the way I resumed my expedition into the heart of the Virgo Cluster, this time picking up from near Vindemiatrix (Epsilon Virginis).

NGC 4762, galaxy, Virgo
Small, edge-on galaxy positioned between two field stars. Bright, needle-like core.

NGC 4689, galaxy, Coma Berenices
Large, faint round galaxy, a little brighter towards the centre.

NGC 4654, galaxy, Virgo
Large, amorphous galaxy, a little brighter than 4689. Three bright field stars on western side.

NGC 4639, galaxy, Virgo
Faint, extended galaxy in same field of view as 4654. Stellar nucleus with averted vision and faint star just east of the core.

M90, galaxy, Virgo
Following on from previous observation (it seemed a little fainter tonight). Large, extended galaxy with very bright stellar nucleus. I couldn’t see the “shell” structure noted previously, but there did seem to be a sharper, darker cut-off along the eastern side.

NGC 4571, galaxy, Coma Berenices
Back across the Virgo/Coma border. Very faint galaxy immediately SW of bright star. Barely visible with averted vision.

M91, galaxy, Coma Berenices
Fairly large round galaxy with bright, but not stellar core. Seemed like there was a dark area east of the core, but the wind made it hard to be certain.

M88, galaxy, Coma Berenices
Bright elliptical galaxy with field star NW and two more SE. Slightly extended core. Seemed to be a faint spot east of the nucleus; in some moments it appeared star-like, in others it was fuzzy.

NGC 4474, galaxy, Coma Berenices
Small round galaxy southwest of M88. Brighter towards the centre.

NGC 4459, galaxy, Coma Berenices
Compact little galaxy just west of bright field star. Very bright core, but not stellar.

NGC 4477, galaxy, Coma Berenices
Bright, round galaxy. Stellar core; otherwise featureless. The northern end of Markarian’s Chain, depending on where you take the starting point (some extend it to M88).

NGC 4473, galaxy, Coma Berenices
Elliptical galaxy – smaller than 4477, but with a brighter core.

NGC 4458 & NGC 4461, galaxy pair, Virgo
Close pair of galaxies in Markarian’s Chain. Both small, but 4461 clearly brighter and more elongated than 4458.

NGC 4435 & NGC 4438, interacting galaxies, Virgo
“The Eyes”. Bright, well-matched pair. 4435 has a very bright core, but 4438 is larger, more extended – and also distorted. The core brightness is probably similar to 4435, but less concentrated.

M86, galaxy, Virgo
Large round galaxy. Brightness increases smoothly towards the core; at the centre of which resides a stellar nucleus, but otherwise this galaxy appeared featureless. NGC 4402 suspected with averted vision to the north, but not confirmed.

M84, galaxy, Virgo
Another bright elliptical. Not as large as M86, but has a very bright core.

NGC 4388, galaxy, Virgo
Inclined, narrow galaxy forming an equilateral triangle with M84 and M86 (but not as prominent as those two giants). Brighter towards centre.

NGC 4387, galaxy, Virgo
Faint little galaxy at the centre of the M84/M86/NGC 4388 triangle. (All four galaxies in the same fov at 92x.) Stellar nucleus with averted vision.

NGC 4440, galaxy, Virgo
Bright, round galaxy. Brighter towards core.

M87, galaxy, Virgo
Not surprisingly, the biggest, brightest galaxy observed tonight. Large bright core, but no stellar nucleus that I could see. Large halo extending almost halfway towards NGC 4478. Of course, astronomers have known for a long time about the super-massive black hole at the centre of M87, but now that we've seen it, observing this galaxy takes on a special significance. Truth be told, there's not much to see in the way of detail (you need a very large telescope to glimpse the jet), but that didn't stop me from staring at it for a long time.

NGC 4478, galaxy, Virgo
Companion to M87. Like a smaller, ghostly light echo of its monstrous big brother.

And then, to round off the session, a quick excursion to the southern region of chart B1.

NGC 4665, galaxy, Virgo
Bright little elliptical galaxy. Bright centre; field star to south.

NGC 4636, galaxy, Virgo
Bright compact galaxy with mottled outer envelope hinting at structure (though, looking at online images later, I may have been deceived by an unusual smattering of faint foreground stars). Home of a recent 12th magnitude supernova – though I arrived about a month too late to see it.

There are still plenty more galaxies to see in the Virgo Cluster (and many of the ones I’ve already logged are worth revisiting at a higher magnification), but this feels like a good place to stop for now.

Exploring the Virgo Cluster (Part 1)

18 March 2020, 21:30 – 23:45

Conditions: After a warm sunny day, an evening that started mild and got progressively chillier. Low breeze with occasional gusts of wind. A slight haze in some parts of the sky, and overall the transparency wasn’t quite as good as Monday. But all the neighbours’ lights were off for once, which certainly made a difference in the part of the sky I was targeting. Thin layer of condensation on the scope and on the atlas by the end of the session.

Seeing: Average
Transparency: Average

Gamma Leonis, double star, Leo
Superb sight at 171x. Pale yellow pair of stars.

NGC 188 (Caldwell 1), open cluster, Cepheus
Loose, misty spray of stars – well framed at 92x. Better resolution at 171x, but at this magnification it looks less like a cluster and more like a moderately rich star-field.

NGC 4889 (Caldwell 35), galaxy, Coma Berenices
Follow-up from Monday at 92x and 171x. The two main galaxies of the cluster (4889 and 4874) seemed fainter than they did on Monday, but were still visible at both magnifications. I couldn’t see NGC 4889’s “companion” on this occasion, but curiously there did seem to be a star-like point on the opposite side of the galaxy. Not sure if this was a foreground star or the interacting pair NGC 4898AB.

M64, “Black Eye Galaxy”, Coma Berenices
At 171x this galaxy was bright and large, with a mottled outer envelope and a star-like nucleus. The famous “black eye” was clearly visible with averted vision, appearing as a kidney-bean shaped patch of darkness on the northern side of the core. This feature wasn’t quite so obvious at 92x; nor indeed was the star-like nature of the nucleus.

M53, globular cluster, Coma Berenices
Helpfully visible in the finder, and appearing as a condensed fuzzball at 171x. Resolved fairly well with averted vision, but not a patch on M3. Brightest member of the cluster (assuming it is a member) on the north side of the core (as noted last year). After staring at it for a while the cluster seemed to take on a vague starfish shape. Still no sign of NGC 5053 – even when I dropped down to 92x.

I gave up on NGC 5053 and switched my attention to the Virgo Cluster of galaxies, approaching it from the south rather than the north for a change. I also switched charts to my trusty old Sky Atlas 2000.0. The Virgo Cluster Chart in the Pocket Sky Atlas is extremely useful for small telescopes, but - as I discovered last year - it's a little hard to navigate with a 10-inch scope. Chart B1 in Sky Atlas 2000 shows a greater number of galaxies (but not so many that the chart becomes saturated with information), and the scale is large enough to depict them at their correct size and orientation (making them much easier to identify in the eyepiece). The chart also extends further south than the one in the PSA.

All subsequent observations at 92x (13mm Ethos).

You don’t need a red-dot finder, a 9x50 finder and a 100-degree
eyepiece to tackle the Virgo Cluster … but they really do help.

M61, galaxy, Virgo
Large, round mottled haze. Over time, and with averted vision, a star-like nucleus became apparent, along with a central bar (aligned north-south) and a possible reverse-s spiral. This detail was elusive and I wondered if I was overreaching with my notes, so I was pleasantly surprised the next day when I looked this galaxy up and found that my description matched its appearance. (The last time I looked at it was 15 years ago with a 4-inch refractor.) Maybe I should trust my own eyesight a little more.

NGC 4526, galaxy, Virgo
Another one I haven’t seen for 15 years. A small, bright lens-shaped galaxy with a bright core and a faint star to the south. This one’s easy to find (and identify) because it’s positioned midway between two 7th magnitude stars.

NGC 4535, galaxy, Virgo
Oval-shaped misty patch; not very condensed. Star near northern edge.

M49, galaxy, Virgo
Round, bright galaxy; quite bright towards the centre. Star east of core.

NGC 4608, galaxy, Virgo
Small, round galaxy near Rho Virginis. Bright core; faint star due west.

NGC 4596, galaxy, Virgo
Oval galaxy near 3 field stars. Bright core; brighter than 4608.

M60, galaxy, Virgo
Bright, round galaxy; very bright core. Large hazy galaxy (NGC 4647) immediately north-west of M60. M60 occupies an impressive field in the Ethos – there’s a lot going on.

NGC 4638, galaxy, Virgo
Small, lens-shaped galaxy roughly west of M60. Bright, bar-like core.

M59, galaxy, Virgo
Bright, round galaxy in same field as M60 (but not as bright). Stellar nucleus, star to north.

NGC 4660, galaxy, Virgo
Small, condensed galaxy with bright stellar core.

NGC 4567/4568, “The Siamese Twins”, interacting galaxies, Virgo
Irregular misty patch; on first impression its bi-lobed appearance reminded me of the Crab Nebula. The south-eastern component (NGC 4568) seemed larger and brighter.

NGC 4564, galaxy, Virgo
Small, bright oval located near a very close double star. Aligned roughly east-west. Star-like core with averted vision.

M58, galaxy, Virgo
Large, bright extended galaxy. Tough to make out any detail other than a bright core.

M89, galaxy, Virgo
Very bright, condensed galaxy. Bright core; faint star east.

NGC 4550/4551, galaxy pair, Virgo
Close pair of galaxies in same field as M89. 4550 seemed slightly brighter than 4551.

M90, galaxy, Virgo
Large, bright, extended “Andromeda-style” ellipse with star-like core. The brightness seemed to fall away from the centre in discrete “shells” rather than a smooth gradation, but I’d need a longer look at it to be sure. Regardless, it was noticeably different from the other galaxies I viewed tonight. (The one knock against the otherwise spectacular Virgo Cluster is that it's dominated by bright - and relatively featureless - elliptical galaxies; hence the repetitive descriptions.)

At this point (23:45) the sky rapidly clouded over – but it was in all the forecasts, so I wasn't surprised when it arrived. M87 and the wonders of Markarian’s Chain will have to wait for another night, which is probably just as well. As I discovered tonight, the Virgo Cluster has so many galaxies within range of my scope that you can’t reasonably tackle them all in one session.

Nature note
The frogspawn is no more, but I now have a pond full of wriggling tadpoles.
Also: one cat on the roof.