Archive for May, 2013

Early to bed, early to rise

Blog Thursday May 16th 2013

 

With the summer solstice fast approaching and darkness getting more and more scarce at 52 deg north it is time to adopt my summer observing program, namely early to bed up around midnight for a couple of hours observing and then back to bed, back up at 6am for work.

When I arose at 00.15am local time, it was partially clear; I made my tea, turning this into a ‘brew & slew’ session. Once into the observatory I consulted the Kanipe & Webb Arp atlas for a target, deciding to keep low I picked Arp 254 down in Libra. A slewed the scope and centred and synchronised on Saturn. I sat there watching it on the monitor for 15 minutes or so as cloud dimmed it right down, eventually the cloud from the west passed  and I bright star hopped to my target, centring on a mag 10 star close to the 3 galaxies marked. I sketched the star field and let the video run a refresh, building up the galaxies bit by bit adding detail when ‘extra’ showed on those clearer frames, rather as I would when planetary or lunar sketching when moments of steady seeing let you grab that extra detail.

An interesting thing happened whilst I was intently focussed on the Arp on the monitor of the course of 1-1.5 hrs of study no less than 5 steady satellites passed W-E through the 11’ field, taking around 45 secs to pass all the way across, all were within 5’ north or south of 105 Librae, this was a first to me, how unusual in the wider scheme of observing I have no idea?

Here is the sketch:

Arp 254

 

The northern most galaxy showing arm structure in my sketch is NGC 5917, mag 14.5, directly south and to the east of mag 9.96 star 105 Librae and extending N-S is MGC-1-39-3, aka PGC 54817 at mag 14.7, large professional scopes show the upper arm extending up to NGC 5917 forming a bridge. The tiny galaxy to the eastern edge of the fov is unknown at the time of posting.

 

With the sketch completed, I stood out in the observatory letting my eyes become fully dark adapted, the Sky Quality meter reading showed a steady 20.75 across the sky, which these days I would say is a good reading for my location. With the Key Stone asterism of Hercules high over head, I used the southern wall to shield the brighter southern horizon and I stared up trying to catch M13 naked eye, just on 2 occasions with averted vision I felt I got a quick flash of it, fun to try and pleasing just to get what I must note as a possible sighting. With Cygnus well up to the east, the Milky Way looked wonderful flowing southwards.

And so to bed, just past 2am local time. Dale

A Wild time with a Pretzel

Blog Wed 1st May 2013

 

Straight in here and back on the trail of the Arp peculiars!

My first of two for the evening Arp 248, also known as ‘Wild’s Triplet’ turned out to be a tough group, way down in lower Virgo. The upper galaxy in the sketch below (NNW of the field) is MGC 1-30-34 mag 15.9. With the more obvious main pair located centrally on the left is MGC 1-30-33 mag 14.1, to the right (W) is MGC 1-30-32 at mag 15.3. The tiny & faint galaxy, barely visible just below is known as “Apmusks galaxy” at mag 18. I Googled this strangely named body at the time of writing and came up blank, it really is just a tiny fleck close below MGC-1-30-32 which is the right of the 2 main galaxies.  The Sketch was made with everything turned to max on the camera! SQM was a poor 19.3.

Arp 248 'Wild's Triplet'

Being low already I stayed low and next for my studies was Arp 22 (NGC 4627) a lovely looking single armed spiral Located in Corvus Arp 22 has a companion NGC 4027a to the south. To my mind 22 should have been relatively easy to see at mag 11.7 but it wasn’t, being so low in the southern murk is likely why! A very interesting object nonetheless and one I dubbed ‘the Pretzel’ perhaps it should be Nelson’s Pretzel having just one arm!

Arp 22 "Nelson's Pretzel"

Again the sketch was made with everything turned to max on the Watec Video cam!

That’s it for tonight, before I go I have to say I’m loving chasing the Arp’s 🙂

Arp 161 jet trail

Blog Tuesday 30th April 2013

 

I grabbed just one observation last night, I considered comet PanSTARRS as inspired by Andrew Robertson’s dramatic observational drawing from the previous night showing fan like anti tail!

Andrew's PanSTARRS sketch

 But with it still out of pointing range of the main observatories scopes I found myself again working from the Arp atlas. I picked one out that was well placed in Virgo up against the Leo border, Arp 161 aka UGC6665 turned out to be a real challenge! It was not only the location that caught my eye, but the ’emanating jet’ nature of this galaxy that excited me, yes another one after Arp 138 from the previous evening!

I got the galaxy easily with my usual star hoping to negate the goto inaccuracies. Initially the jet & plume were pretty obvious, but as frames refreshed and I tweaked the camera control box, for gain, exposure etc both jet and the even more elusive plume disappeared, monitor setting for brightness and contrast were also adjusted, these in combination with the video camera controls as you can imagine have an infinite combo of setting potentials. With practice over what must be 7-8 years now I have a pretty good knack of getting the best image before ‘marking the paper’.

However you can’t adjust out bad seeing, the analogue video camera has eyepiece realism with faint objects and stars coming and going at every ‘refresh’.

The jet and extended plume that I had almost nonchalantly expected to see and sketch leisurely were proving much tougher than I had anticipated. At the time of writing I have no idea of their comparative brightness. The conclusion was that I sat there for nearly an hour before I made my rendition on paper, for something that will look so simple to you, it was very difficult to capture, or rather to try to capture as it appeared. Features such as the couple of very faint stars close into the extended halo of the galaxy appearing only fleetingly and on most apparitions looked rather like a jet themselves, tricky.

Arp 161 complete with Jet & Plume

Anyhow here you have my sketch of what is when you consider it a mind blowing object seeding out into the vast universe. The excellent book ‘The Arp Atlas of peculiar galaxies, Kanipe & Webb’ states it has been seen, the jet and plume that is with a 20″ under what I can only assume are pristine sky conditions, another observation with a 25″ just describes the galaxy with no extensional activity, a challenge for my pals off to Tenerife to explore the deep heavens with Rod’s 25” on mount Teide perhaps?

Best, Dale

Saw some nice stuff!

Blog Monday 29th April 2013

 

After a busy very garden weekend both at home and on the allotment, Saturday night out under the stars, a flying visit to Aldershot and back on Sunday and finishing the weekend off with a late night out at the Folk club, I was flagging when Monday evening offered a clear sky! But with the ongoing run of cloud wrap the UK has had, no opportunity should be missed for starlight! So just one sketch I told myself.

Ok so e start off with Arp 138 aka NGC 4015 located in Coma Berenices right onto the border with Leo, a very interesting galaxy with what I believe is a jet emanating from its western side and extending SW-NE. Other galaxies in the sketch are NGC 4021 top left, NGC 4011 to right, NGC 4023 bottom left. To be able to witness such massive forces in action far out across the universe is a privilege of very few people on earth and that is just how I feel, privileged.

Arp 138, would you look at the jet from that!

 

 

OK with this Arp and neighbours safely to paper I scouted the local vicinity for anything else of interest whilst I was there, so much for just the one sketch! There were no shortage of galaxies very close, one group caught my eye and I moved the scope to encompass as many as I could in the small field of view what I got was fantastic group of diverse galaxies just into Leo and just to the west of Arp 138. In a clockwise direction from top right in my sketch below we have NGC 3993 at mag 11.83, showing nice spiral structure, next  there is  tiny NGC 3989 with a tiny hook like feature of detail observed, mag 14.9, to the west, an amazing edge on with stunning dust lane, NGC 3987 at mag 13.1. Last but not least to the SE next to a bright mag 8.2 star, is a faint, very thin, very straight edge on, N-S orientation, this is NGC 4000 a mag 14.5 absolute beauty 🙂

NGC 3933 and neighbours a good looking bunch.

 

Right it’s time for bed, one more sketch in the bag than I had intended so not bad, but with the need to be up for work by 05.30am I closed up.

Starting a new list!

Blog Saturday 27th April 2013

 

With my Hickson quest rather stalled by either the remainder being inaccessible from my location/observatory or the ones I require not currently being in the sky I needed some new interesting targets to get on with. Now my good friend and observing pal in Chicago, USA, Frank MaCabe had already arrived at a solution for me, providing the excellent ‘Atlas of Arp Peculiar Galaxies’ by , Kanipe & Webb as my follow on challenge for when the Hickson’s were conquered!

With well in excess of 300 targets in this list I had better get going! Tonight was a lovely evening but the Moon just a couple of days past full would be rising relatively soon after dark, so no hanging about.

 First to fall to the 20” optics and video camera was Arp 105 in Ursa Major made up of NGCs 3561 at mag 14.7 and NGC 3561A at mag 14.3.  This is a very nice area to get lost in for a few hours as it is packed with small galaxies. These two galaxies are on the eastern side of Abell 1185, a cluster of 52 galaxies so a very interesting field. Dr. Arp thought enough of this object and its immediate environs that he used it for the back cover of his book, “Seeing Red”  

Arp 105

No time to waste with the sky brightening continually and onto Arp 270 in Leo Minor this is a visually exciting pair of interacting NGC galaxies, 3395 & 3396, both being mag 12.1. Perhaps I was now rushing a little too much and could have produced a better sketch, I certainly wasn’t too happy with the roundness of my stars when I scanned in the evenings drawings!

Arp 270 an interacting pair

 

Really I should have called it a night as the moon was now up and washing out the sky, but I had been caught by the lure of a rather nice face on spiral NGC galaxy close by, something of a M101 look alike! NGC 3938 is a very attractive face on spiral galaxy back into in Ursa Major. It was discovered on 6 February 1788 by William Herschel and is one of the brightest spiral galaxies at mag 10.9 in the constellation. Interestingly a SN was discovered in the galaxy in 2005 at mag 15.6.

NGC 3938 is quite a looker!

I’m sure I could have got more detail without the moon in the way but it still made for a nice spectacle.

 

And so to bed, Dale

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