Archive for May, 2012

In the still of the night

Blog for Friday 25th Sat 26th and Sunday 27th May 2012

 

With the shortest night fast approaching a dark ‘astronomical’ sky is a short affair! With a rare run of hot sunny days & clear nights upon us I needed to modify habits. For me this means early to bed grab a few hours sleep then arise again at around midnight for a few hours of observing until the pre-dawn sky brightens. I would need these opportunities to catch up with the considerable number of Hickson compact galaxy groups around Bootes, Serpens and Hercules which are well placed at this time of year.

OK I have set the scene so we start with Friday night into Saturday morning, up and with a mug of tea in hand this is a true ‘brew & slew session’. First stop off was actually a distraction! I was intending to sketch NGC 4485/4490 the Webb society galaxy of the season in Canes Venatici, also known as the Cocoon galaxy and ARP 269. I star hoped up to CVn via Virgo when I spotted M106 in Canes Venatici on my planetarium software, hmmmm I though, I don’t think I have sketched that? I went through my Messier file and indeed that slot was empty. I locked onto the Messier galaxy and brought it up on the monitor…..Wow it was bright and big! I could have done with using a focal reducer but I didn’t have the time to mess around  M106 is a large and exciting galaxy the Watec camera and big mirror really did  pulled out masses of detail and structure, quite wonderful! See my sketch here

Next I did catch up with NGC 4485/4490 as I said above this too is in CVn the constellation of the ‘hunting dogs’. A very exciting pair of interacting galaxies 4485 being the smaller and looking like it is having the stuffing pulled out of it by larger 4490, both are actually spiral and were discovered by William Herschel on Jan 14th 1788. It is actually NGC 4490 mag 9.4 which is referred to as the ‘Cocoon galaxy’. See my sketch here

Finally I did get a Hickson! By now it was well into early morning of the 26th HCG 74 was a tough observation there are 5 members of this group in Serpens which is not the most exciting visually members being small, faint and spaced out. The (E) member is tough at mag 18.2! See my sketch here

Time to go back to bed and try and sleep, that is tough too ;¬)

Dale

Saturday night into Sunday morning, brewing and slewing again and off in search of more faint smudges in Serpens. I picked up where I had left of that morning, starting with the next on the list HCG75 and although after midnight local time it was before 00.00UT so technically a “Double Ender” for meJ. Right back to the observation, HCG 75 isn’t visually too exciting, 5 members all tiny ranging from high mag 15’s across mag 16’s, with a centrally placed PGC 54803 being both largest and brightest at mag 15.7. Not to grumble, another one down and a pigeon step closer to the 100th! See my sketch of HCG75 here

Next up we are onto HCG83 across towards Ophiuchus but actually one of the 3 Hickson groups in Hercules. This group I would say is the toughest I have observed to date, and I have seen a very commendable visual observation with a 22” F4 under a pristine sky, from my perspective I suppose you could say it was straight forward enough if you know what is what! But discerning the members from being anything else but stellar was very difficult, I dwelt on this group for an hour plus cross referencing tiny bright spots on the monitor with maps and CCD images in my reference material, ascertaining what was a star, a galaxy of just back ground noise on the monitor screen, I had chilled the camera down for a few hours in the refrigerator to keep the noise and hot pixels to a minimum on such a warm night, I’m glad that I had otherwise I may have missed off some of the very faint members! All members of the group are designated PGC 58559 A-E so 5 members in total, (A) being mag 15.8 and (E) being 18.9. I won’t say anymore as I wrote a few notes detailing each member and my thoughts so I will let both b&w sketch see here and the detail sketch see here speak for themselves!

Onwards and upwards, sticking in Hercules I push onto HCG81 closer in the direction of the well known Key Stone asterism that characterises Hercules. After HCG83, 81 appeared bright and obvious although on paper it isn’t, it jumped out at me on the monitor screen, less stars in the field for starters certainly helped.  HCG 81 is a 4 galaxy group arranged in an arc, almost like a paw print, members are designated UGC 10319 (A)-(B), take a look at my sketch here

OK that is 2 out of the 3 Hercules Hickson’s, but it’s the weekend so I intended to push onto the 3rd, HCG82 which lies just to the west of the Key Stone.  However my eye was caught by a planetary nebula showing up in my software within Hercules, IC 4593 (white eyed pea) is small PN catalogued at 15×11 arc seconds although most observers consider it to be smaller, bright, the usual fuzzy stellar jobbie at low powers, I confirmed this by doing a visual through the 6” at 70x, I wanted to sample the colour, no filter, to me it looked blue grey but other have stated, greenish, I won’t argue my dark adaption wasn’t that good! Using a x2 barlow lens before the camera to increase the image scale, I played around for some considerable time with focus, camera settings and monitor setting before I got the best image in terms of detail and minimising ‘burn out’ due to the brightness of the object. The central star was easy, the shape was circular, a small ring and when I got things just so, I could see extensions in the form of ansae extending NW & SE, a very nice little planetary that was worth the considerable effort to get presented at its best. See my sketch of IC 4593 here

And so to bed as dawn broke on a warm Sunday.

Here I am out again at 23-00UT midnight on Sunday night so another ‘double ender’ I’m eager not to spend too long outside, I have to be up for work at 6am local time.

I go straight for Hickson 82 which turns out to be the most interesting of the 3 Hercules groups, the members all contrast in shape and size. The 2 main member galaxies (a) NGC 6162 & (b) 6163 form a pair of round eyes, the left slightly fainter showed a hint of spiral arms with my set up, (c) member NGC 6161 is a little gem, looking like an exclamation mark with a star on its southern tip, I was able to pick out a dust lane bisecting it e-w, last but not least (d) PGC 58231 is a tiny but very recognisable edge on. See my sketch of Hickson 82 here

I have time left to push on into Lyra and go for planetary nebula NGC6765 which is a Webb Society object of the season. This isn’t my first observation of this interesting and quite unusual nebula, but I think at the time of writing that it may be the first that I have made with the 505mm mirror. Anyhow without further ado, this is a small nebula with a central elongated region resembling a segmented bacterium under a microscope in my eye; there are arcs of material curving to both east and west but more noticeable to the east, so the overall appearance is somewhat ‘keyhole’ like. Please take a look at my sketch of NGC 6575 here

That’s all folks, I hope to be back soon with more exciting objects from outer space! Dale

Seyfert’s Sextet and a couple of other Hickson’s

Blog for the night of Tuesday May 22nd 2012

With the New Moon window ‘leaking away’ with no observing opportunity it was with delight that the weather changed. I’m not picking up my Hickson observations at the pace that I would like and with the late spring into summer window of observable dark sky being very narrow getting some under my belt over the May June & July New Moon periods is essential if I’m to catch those groups which are well presented during the period commonly known as ‘the closed season’

So you will have gathered by know that I got a clear one! With Andrew Robertson away on Mount Tiede, Tenerife with Stewart Moore (BAA Deep Sky Section Director) Dave Balcombe & Mark Turner friends of mine from the Norwich Society and telling me of the wonders they were enjoying night after night at 28 deg north with a 25”. I needed to get some in for myself.

There were lots of targets that I wanted to catch up with in Virgo, galaxy of the season etc for the Webb Society and others on a list in the observatory, but as much as I would like to look at brighter or tricky exciting challenges I must stay focussed to the Hickson challenge and complete that before I dally off in other directions.

My target constellation is Serpens, plenty of the little Hickson smkudges showing on my chart there. I didn’t start working seriously until post 11pm local time due to the light sky, it also gave me chance to collect my son from Army Cadets, practice my Harmonica and enjoy (some of the performers on) Jools Holland Later on the TV.

I star hoped up into Serpens from the horizon via Virgo and onto my first catch HCG 76 With 7 members that are well spread out, this group in Serpens is a tough one. The edge on galaxy to the upper right in my sketch is PGC 55307 (g member) and is mag 17.5! See my sketch here

Next I tackled HCG 77 another tough group in Serpens but a a more interesting one with 4 members UGC 10049 A-D, the brightest being 16th mag! the faintest (D) mag 17.2 even with the watec (D) appeared to be continuous with C, the Palomar Survey imaged showed a slight dark dust lane dividing them! On a better night I should have got that, but by now the haze was turning to fog (well that is my excuse) this is the closest yet I have come to not being able to detect a HCG group member! See the sketch here

Last up for the night was the most interesting and rather well known HCG 79 better known as Seyfert’s Sextet again in Serpens with an attractive outline, 4 members NGC 6027 (A) through to (D). (B) is the most interesting with spreading arms like an Acer seed. (D) member to the lower right was a tough observation, perhaps due to haze although the Sky Quality meter read 20.75, mag for this member is listed as 15.3 See my sketch here

Dale

From the dazzling to the dim, distant and difficult!

Blog for Friday 11th and Saturday 12th of May 2012

 

To say that we had endured something of a dearth of observing opportunities in the UK during April and the first 2 weeks of May is an understatement. That fact made these clear Friday and Saturday nights all the sweeter.

I had encountered a few technical issues with the mount and software during my last observing opportunities that Es Reid had supported me with. Since then I had acquired a new lap top and at setting this up found that there was a faulty cable that connected the lap top to the AWR intelligent handset, this was replaced at the cost of £23 from Alan Buckman of AWR.

On firing the scope up on Friday night I found that the Dec drive on the mount was working the wrong way, in other words, sending the scope up, actually resulted in it going down!

I called Andrew Robertson in Norfolk who is something of an expert with the AWR set up’s, I’m certainly not! Thankfully he talked me through getting into the factory settings and re-setting so all was well and I was able to continue.

For some reason & I can’t recall why? Rather than getting straight back on with my obsessive hunt for Hickson Compact galaxy groups I went for M60 in Virgo and its close and rather more interesting neighbour NGC 4647. M60 is bright and large but rather featureless whereas NGC 4647 although smaller and considerably fainter offer glimpses of spiral arms. See my sketch of the duo here

Keeping things bright, I went for a ‘black eye’ with M64 this gem needs no introduction and on my b&w monitor it looked just sensational, I sat there for a while wowing to myself and taking in the dramatic detail before I started to sketch this

After a couple of blasts of bright photons, I reverted back to the dim, distant and difficult, Hickson groups. First I reeled in HCG 70 a collection of 7 tiny smudges to the west of the Bootes kite, 2 appear as tiny flying saucer shapes, the (f) member is most challenging even for my set up being so small and faint at past 17th mag! See what I sketched here

Swapping to the eastern side of Bootes my next catch was HCG 72 once again, made up of tiny and faint members, this time 6 in a close tumbling cascade running from UGC 9532(a) to the north down to UGC 9532(f) at the southern tip of the cascade, see my sketch here

Well that is where I called it a night at around 2am local time. I Picked things up the following night around midnight by catching up with HCG 73 to the north of HCG 72. Visually this was a little more interesting, the brightest member being a rather attractive face on spiral galaxy NGC 5829 (mag 13.1), the other members are scattered to the north and east and were little more than smudges some exhibiting elongation and brighter centres the faintest (e) member was tough at mag 17.6! See my sketch of HCG 73 here

 This took my tally to 53 and on reflection remarkably I have so far been able to detect every member of each of the 53 groups! I wonder if I can take this success right through to number 100?

Dale

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