Observing report March 7, 8 (and now 9th)

I've been warming up with brighter targets, which has also given me the opportunity to fill in some holes in my Messier sketch collection:

M82 3/7/2010 20:40 UT; Pickering 8, NELM 5.5, SQM 20.5
400mm Mak-Cass @ 225X

Three angular dustlanes separating two distinct core regions and two outer disk regions. WSW core contains a semi-stellar condensation, while the larger ENE core contains several brighter knots. WSW outer disk somewhat brighter than ESE, and contains a distinct angular feature pointing SW.

I then went on to an irregular member of the M81 group. My buddy Dale managed to get some of the interior dust regions with his Watec-enhanced 20", so I was curious to see if it could be done with the old eyeballs:

NGC3077 3/7/2010 21:10 UT; Pickering 8, NELM 5.5, SQM 20.5
400mm Mak-Cass @ 225X

Very poor condensation with an extended core tapering uniformly to E, somewhat less-so to S and NE, and abruptly to NNW. Somewhat grainy at 150X, giving it more the look of an unresolved globular than a galaxy, and the shape contributes to a cometary appearance at 335X. Interior dust regions not visible.

Nice tight double to NNW and another (outside field) to W. [ADS7611 and ADS7603. Both are about 3.3" separation, and have an interesting history of being confused with each other.]

Arp82 (NGC2535, 2536) 3/7/2010 21:46 UT; Pickering 8, NELM 6, SQM 20.6
400mm Mak-Cass @ 225X

Quite small and dim. Borderline direct/averted vision, but too small to make out any detail at 150X. 235X helps image scale and provides fleeting glimpses of a stellar core (perhaps 25%), but the galaxy is distinctly averted-vision at this exit-pupil. 335X too dim.

235X also reveals second galaxy to SSE [NGC2536], with a similarly fleeting stellar core. It's also visible in averted-vision at 150X when you're looking for it.

This Hickson compact group looked like it might be decidedly difficult in the DSS image, but it turned out to be quite nice:

HCG57 3/7/2010 22:00 UT; Pickering 8, NELM 6, SQM 20.6
400mm Mak-Cass @ 325X

Smudgy area at 150X, with one definite condensation and another probable. 235X confirms both [NGC3750, 3753], with haloes nearly touching, and adds 2 more possibilities to the NW of the first pair. 335X confirms second pair [NGC3746, 3748]. [NGC3745, which lies between them, not seen.]

[Southern-most field star of sketch is likely the core of NGC3751.]

Arp94 (NGC3226, 3227) 3/7/2010 23:01 UT; Pickering 8, NELM 6, SQM 20.7
400mm Mak-Cass @ 225X

Fairly bright pair at 150X. Southern component [NGC3227] with stellar core and N-S elongation, northern [NGC3226] with semi-stellar core and roughly circular shape. Haloes touching, or nearly so. At 235X, southern component shows a dark lane to the E of its core.

Oh, and here's an "extra" from a few nights ago (note that the partial illumination is getting quite visible):



Cheers,
-- Jeff.

Gorgeous collection , love them all


Deirdre Kelleghan
Vice Char IFAS - Outreach IFAS
National Coordinator Astronomers Without Borders Ireland .
www.irishastronomy.org/
www.deirdrekelleghan.com/
twitter.com/skysketcher

I thought I was doing well to see detail in M82 last night in my 8 inch. Your sketches are great. They are also impressed over on the Cloudy Nights forums.
Donal

Thanks, Dee and Donal.

I've got another set from last night, but I don't have them scanned yet.

-- Jeff.

Who'd have ever thunk we'd get two clear nights in a row in Ireland? [Stranger still, we actually got three. But I don't have the sketches scanned from last night yet.]

NGC2903 3/8/2010 22:41 UT; Pickering 9, NELM 6.5, SQM 20.8
400mm Mak-Cass @ 150X

Elongated moderately condensed core with further mottling surrounded by a large elongated disk. Dark lanes to both sides of core, all along W west edge but only along northern half of E edge. Bright section at NE extend of disk sweeping toward NW. Core brighter than most field stars at 150X.

IC750 3/8/2010 23:00 UT; Pickering 9, NELM 6.5, SQM 20.8
400mm Mak-Cass @ 150X

IC750 shows as a reasonably bright, small streak with a highly condensed, elongated core. IC749 larger and circular, but much dimmer and with no appreciable condensation. A bright field star forms the 3rd member of an interesting trio. [The sketched field star due S of 750 turns out to be the stellar core of IC751.]

Abell 1367 3/8/2010 23:16 UT; Pickering 9, NELM 6.5, SQM 20.8
400mm Mak-Cass @ 110X

Glare of SAO 81972 really nukes this field. I get 4 members at 110X, all with stellar cores, but it isn't very visually rewarding. HCG57 was much more interesting.

NGC4147 3/8/2010 23:40 UT; Pickering 9, NELM 6.5, SQM 20.8
400mm Mak-Cass @ 325X

Clumpy, but no stars resolved at 110X. 235X resolves 4 stars around the periphery while 335X resolves a few in the core. Past that the gains start to tail off; 450X shows a total of perhaps 8 or 10 stars across a milky background.

UGC3697 Integral Sign 3/9/2010 00:10 UT; Pickering 9, NELM 6.5, SQM 20.8
400mm Mak-Cass @ 225X

Poor condensation, roundish. Is this even the right galaxy? [No, it's UGC3714.]

Oh, wait, there's a very dim ghostly streak to NNW of elliptical. I had thought the bent ends would be out of reach, but the whole thing has a nearly uniform brightness, with the curl at the east end perhaps somewhat more detectable than the west. "Detectable" is key here; I can't really say I can "see" any of it, but the narrowness of it seems to be an excellent trigger for the eye's edge detection when sweeping across it. At any rate, it's very easy to reacquire in averted vision, particularly for a target this dim.

Fantastic target: breathtakingly etherial, with an emotional impact similar to NGC891 or the Veil.

The Integral Sign has definitely moved on to my favourites list. I only wonder if it would be visible at all on a less-transparent night?

Cheers,
-- Jeff.

And last night:

M67 3/9/2010 22:16 UT; Pickering 8, NELM 6, SQM 20.7
400mm Mak-Cass @ 110X

Large cluster of about 100 members, mostly of a similar magnitude and color, with one prominent straw-coloured star to the NE edge.

NGC2775 3/9/2010 22:26 UT; Pickering 8, NELM 6, SQM 20.7
400mm Mak-Cass @ 225X

Moderately condensed circular core surrounded by slightly elongated halo. Averted vision shows relatively abrupt edge between core and halo at 235X. The effect is diminished at 335X, where an inner, semi-stellar core appears. Suffers from Drogheda's light bloom.

NGC2859 3/9/2010 22:40 UT; Pickering 8, NELM 6, SQM 20.7
400mm Mak-Cass @ 325X

Tiny, with a semi-stellar core and not much of a halo. Hints of a bar aligned NE-SW.

[I must have been seeing elongation in the inner core. Bar actually runs NNW-SSE, and it and the outer ring are well outside the extent sketched. In fact, the bar runs almost to the dim foreground star to the N, while the outer ring is entirely outside that in radius.]

NGC2964 NGC2968 3/9/2010 23:05 UT; Pickering 8, NELM 6, SQM 20.7
400mm Mak-Cass @ 150X

NGC2964 shows reasonably bright disk but very dim, stellar core. NGC2968 smaller with marginally brighter but semi-stellar core. 2964 irregular in shape with indistinct mottling and a dimmer area to the NE; looks somewhat like a smaller Crab Nebula.

Arp206 NGC3432 3/9/2010 23:30 UT; Pickering 8, NELM 6, SQM 20.7
400mm Mak-Cass @ 150X

Interesting bent-stick of a galaxy with the brighter but somewhat frayed end anchored by a pair of foreground stars and a dimmer, narrower section extending off to the ENE. Very weak condensation just before dimmer section.

NGC3294 3/9/2010 23:45 UT; Pickering 8, NELM 6, SQM 20.7
400mm Mak-Cass @ 225X

Slightly elongated halo (WNW-ESE) of uniform brightness with no core visible at 150X. 235X shows some mottling and a very weak, non-stellar core. 335X shows further mottling, but no more strength to core.

NGC3414 3/9/2010 23:55 UT; Pickering 8, NELM 6, SQM 20.7
400mm Mak-Cass @ 325X

Bright, semi-stellar core with a small halo at 150X. 335X shows more extended halo and a stubby NNE-SSW bar. Pretty similar in the eyepiece to NGC2859.

It's actually clear right now as well, but I don't think I have a 4th night in a row in me.

Cheers,
-- Jeff.