Dark site galaxy fix

[Size9Hex]

The sky on Saturday afternoon was a deep and rich blue. So much more promising than the pale haze of Friday. Time for a dark site trip with the 10". 

It's hard to know what to observe at this time of year - or rather what to leave for next time. The concentration of galaxies in the spring sky is astonishing. Spoiled for choice! Looking back at the log, 35 objects were observed. These were mostly faint Herschel 2500 galaxies observed briefly without any fixed plan other than to explore what was out there. A few of the brighter ones were targeted in advance and studied quite carefully. Selected highlights below. 

Ursa Major

With effort, M81 showed a dark band S to SE of the core which provides the separation to the spiral arm. In a sense, the spiral arm was therefore visible, and yet I can't call it "seen" with there being no sense of any distinct or curved structure beyond the dark band - just a very faint glow which faded away into the sky. Very excited to see this band for the first time though, as detecting a similar dark band in M31 was the key to unlocking a lot of detail soon after. Interested in how other folks see this one.

The M101 Pinwheel appeared to *maybe* show some structure on the edge of perception but not enough to call it. Very hard to pin down - just a lumpy black background perhaps. But... I nearly fell of my chair when the three outer star forming regions NGC 5450, 5461 and 5452 popped into view! To my eye these were easier than the main spiral - well worth a look. This is an enticing target! 

The M51 Whirlpool was just beautiful with swirling arms and companion, but the bridge (which I saw last year) was borderline (if at all), making me wonder that the sky transparency was good rather than exceptional.

Virgo

M104 Sombrero. Another beauty with central bulge, extended disk and a long but subtle dust lane. So happy to finally see this enigmatic galaxy in the 10", with the tick last year being made in the 4".

Canes Venatici

NGC 4618 showed possibly the most prominent spiral arm I've ever seen! Completely unexpected.

Coma Berenices

NGC 4565, Needle Galaxy. Another stonker, with a slightly off centre dust lane.

Hercules

NGC 6195. Just one of many very faint galaxies seen on the night, but it's the one that sticks in my mind. 410 or 470 mly distant according to my two references. Wow! 

M13. It's very impressive from home, but why have I never observed this under rural skies before? Absolutely jaw dropping! The propeller, plus many other streamers and dark lanes.

Comet C/2015 V2 (Johnson) picked up. Nice and bright. Second comet this week!

As I packed in, winter had largely disappeared in the west, while the Summer Triangle had begun to rise in the east. The sky was just sensational.

Thanks for reading if you made this far. Hope others got some good observing in too.

[Knighty2112]

 Nice report Paul. Some nice views there. Transparency was so-so for me last night. Need to get to a dark site myself sometime too!  

[scarp15]

Great report Paul with good detail for describing each of those galaxy observations. I had the Sombrero somewhere on my list, which annually is a must see. Good point that we are in the transition between winter and summer constellations.  Dark sky trips are quite simply just worth the effort and the slightly vacant state of mind the following day.

[Size9Hex]

12 minutes ago, Knighty2112 said:

 Nice report Paul. Some nice views there. Transparency was so-so for me last night. Need to get to a dark site myself sometime too!  

Go for it - it'll knock your socks off! I can see stars to about mag 5.5 at home, but only a few miles away I can see maybe mag 6.3. It makes such a difference, particulately for galaxies and nebulae.

[FenlandPaul]

Smashing report, Paul - really brings across the excitement of teasing out detail.  So excited about spending some nights under the Spring Galaxy-strewn sky!

Paul

[cotterless45]

Can't beat dark sky !

Nick.

[Paz]

Great report thanks for posting.

[alan potts]

Great report Paul sound like you had a really good night.

[mapstar]

Very nice report Paul I enjoyed the read through.

The transparency on Saturday was way better than the friday at the PSP but still mediocre in my experience. Sounds like you had much better skies.

 Keep up the good reports and extolling the virtues of getting out to a dark site.

[Pondus]

Your reports are always a joy to read. To observe a Galaxy (ngc6195) some 500million ly away is amazing.

 

Rune

 

[DeepSkyBagger]

I have to agree with you about NGC 4618. I made an observation of this galaxy a couple of years ago. The prominence of the one, big, fat arm is very peculiar. 

[Size9Hex]

1 hour ago, DeepSkyBagger said:

I have to agree with you about NGC 4618. I made an observation of this galaxy a couple of years ago. The prominence of the one, big, fat arm is very peculiar. 

 

That's a great sketch!

You've got me curious, so looking in the Herschel guide, it reports a probably interaction with NGC 4625 (H660-2) at some point ithe past, with the two together now catalogued as Arp 23. Herschel it seems actually catalogued NGC 4618 as two distinct objects (H178-1 and H179-1). "Two. The north very bright... the south pretty bright... Their nebulosity run together."

[DeepSkyBagger]

NGC 4618  and its neighbour NGC 4625 do indeed form an interacting pair, catalogued as Arp 23. When I made the observation of 4618, I wrote 'A very odd-looking galaxy. It is split into two sections, separated by what looks like a giant dark lane. The brighter and larger section is to the northeast and is like a squashed ellipse with a brighter, elongated central area. Separated from this is a fainter arc of material. Unfortunately, the conditions were too poor for the object to sustain higher powers.'

I had noted that the sky was 'bright and fairly murky'. That probably explains why I didn't attempt NGC 4625 on that night, though I did make observations of eight other galaxies.

Pictures of NGC 4625 show it to be a smaller version of 4618, a single, fat-armed spiral. OK, it's on my priority list for the next clear night!

Maybe it's not so obvious as 4618, for Herschel's description of 660 H.II is 'Pretty bright, pretty large, round, much brighter in the middle.'  No sign of the fat arm syndrome there. 

The comment 'their nebulosities run together', is wrong. That must have been illusory.

[Size9Hex]

Thanks for sharing those notes. Interesting to compare how you saw it. I wonder if I had more luck with the sky transparency on the night. I felt like I was looking at a spiral arm, aligned anti-clockwise (starting from the core and going outwards). I should have made better notes at the time, but my recollection is that the arm was connected (i.e. running together) to the core, almost like a very stylised apostrophe. However, there's always the risk of the brain "connecting the dots" of course, so I couldn't swear for sure that I saw the arm and core ran together, but the anti-clockwise orientation was there for sure. It's nice to have a reason to go back for another look - it really was a beauty to look at! 

Good luck with NGC 4265! Looks a wee bit smaller and tougher, but still a bright core.

[DeepSkyBagger]

I think you're right about the arm being connected on the eastern side, thus giving an anticlockwise appearance. The conditions when I made my observation were rubbish, so I either wait for a better night at home (yeah, right) or I try from a darker sky site. I'll let you know how I get on.

What are your skies like? Any chance of picking 4625 with your 10"?

[Physopto]

11 hours ago, DeepSkyBagger said:

I think you're right about the arm being connected on the eastern side, thus giving an anticlockwise appearance. The conditions when I made my observation were rubbish, so I either wait for a better night at home (yeah, right) or I try from a darker sky site. I'll let you know how I get on.

What are your skies like? Any chance of picking 4625 with your 10"?

Galloway !

 

[DeepSkyBagger]

Won't be visible in November. :-(