M51, M63 (sketched), M94, M3 (sketched) and M53

This observing report also constitutes first light on my new APM MC1610.

After a few days of partly clear but hazy skies (which did allow me to collimate and shim the new OTA for orthogonality), things finally improved considerably in both transparency and seeing. My observing session started with Pickering 8, NELM 5.5/SQM 20.6 skies; as the evening progressed a light breeze picked up and the seeing fell to Pickering 6 or so, but the transparency improved to NELM 6/SQM 20.9.

I started out with a few old favorites to get a feel for the new instrument.

M51 4/30/2008 22:15 UT

Absolutely stupendous at 155x: strong E-W elongation apparent in core, surrounded by two complete revolutions of the arms, including readily apparent HII regions to the SW in the bridge arm and to the ENE and NE in the other arm. Main flare (to N) in companion direct vision, with secondary (W) and tertiary flares (NW) visible in averted. Tertiary flare quite large but very difficult (perhaps 20% in averted).

Stellar core to both members, but companion's actually appears somewhat brighter. Bottom and top of bridge direct-vision; center still averted and somewhat difficult. Beautifully framed at 100x in 39T5 with ink-black background.

Interestingly, only two fore-ground star obvious. I suspect the better-controlled SA of the Mak turns some of what looked like foreground stars in the SCT into HII regions.

Two things stood out from this observation: more detail is available in deep-sky targets with 1/8th optics than with 1/4 and the Mak displays a darker background at low magnifications / large exit pupils (100x / 3.9mm).

M63 4/30/2008 22:30 UT

Flattened disk of moderate size with off-center, semi-stellar core embedded in a fairly bright, grainy central region. Didn't see clumping that gives it its name.

My notes don't show much discernable difference in this target between the SCT and MCT: I don't pick up the graininess in the outer disk with either instrument.

M94 4/30/2008 22:45 UT

*Very* bright non-stellar circular core surrounded by a very slightly elongated (ESE-WNW) direct-vision halo. More pleasing to the eye than the lack of visible structure would suggest.

Also viewed a bit at 330x, where the background was less blotchy than with SCT, and there was slightly less high-magnification-brightening at the field stop, but both effects were still present.

Interestingly, at higher magnifications (250x - 330x) the MCT maintains a contrast advantage, but it's less pronounced than at lower magnifications. I suspect some of the contrast loss I experience when exit pupils are 1.2mm and below has more to do with my eyes/brain than the optics.

M3 4/30/2008 23:00 UT

Fantastic power-keg of stars with perhaps 100 stars resolved over a hazy outer background and milky inner one. Seems smaller than M13 for some reason (perhaps just down to shorter focal-length of MCT?). Exquisitely framed at 100x in 39T5.

Again, the remarkably inky background at lower magnifications is displayed. I think I'm going to be using my 31T5 w/ AP telecompressor a lot more on this scope.

M53 4/30/2008 23:20 UT

Considerably smaller and dimmer than M3. Stars resolved across face at 330x, but still somewhat patchy. Beautiful in averted vision though.

At this point I went back and spent another 1/2 hour with M51. It's such a remarkable target and this instrument shows it spectacularly well.

Cheers,
-- Jeff.

Very nice Jeff.
I really like M3, very nicely done - both of them

great sketches and report Jeff.
Did you manage to make a sketch of M51?

M3 looks AMAZING.

Again.................almost as if you are looking at it directly.

Ive never observed it.....................

But i'm sure it looks exactly like that.

Your sketches are fantastic. I really enjoy them.

Lovely details Jeff, M3 certainly has a 3-D look to it and is a testimony to your skills.

Thanks, guys!

No, Michael, I've never sketched M51. There's so much going on that I find it rather intimidating. I really should have done it last night (it was certainly the best view I've ever had of it), but I chickened out.

Cheers,
-- Jeff.