Observing report 16th January 2011

[Moonshane]

Observing Report 16th January 2011

Location Cheshire, England Latitude: (53°N) Longitude: (2°W)

Equipment – f5.3 300mm Orion Optics UK Dobsonian, Televue and Baader Genuine Ortho eyepieces, Helios Apollo 15x70s.

Main Target: Lunar 100 List

I am really enjoying building my list of observations for the Lunar 100 list and have now seen two thirds of the targeted features. Needless to say, the easy ones have now been seen in the main and the remainder will be trickier either due to being very small features or those which need the correct libration to put them on show.

As always I started with a quick look at Jupiter. There was a reasonable level of detail visible and the seeing was slightly better than average I’d say; all four of the main moons were noted. I could not be sure that the GRS was on show but there was definitely more ‘substance’ to the SEB than the last time I saw it. I did see a white oval in the NEB quite distinctly at one point. The main eyepiece used as usual was the BGO 12.5mm, which at 128x really hits the sweet spot more often than not on this target. I then had a brief look at Uranus which as always just showed a plain pale greenish disk. It has distanced itself from Jupiter quite a bit since I last observed. Jupiter disappeared around the back of my house (you know what I mean!) quite quickly so I turned my attention to the moon which was around 80% full, so rather bright.

I am following the East Valley Astronomy http://www.eastvalleyastronomy.org/obs-lists-pdf/OTL100.pdf

daily lists for the moon and we were on Day 11 according to an online source. However, I usually try to locate unseen targets on the list from a day either side of the actual lunar day. On this basis I had three main targets for this evening, which were Flamsteed P, Prinz Rilles and the Schiller-Zucchius basin. The most used eyepiece on the moon was my Televue Nagler 6-3mm zoom. This is a really excellent eyepiece and the ability to zoom into features requiring as much magnification as conditions allow is great. That said, even the 6mm end of the zoom gives 267x in my telescope; if you use higher magnifications and just wait a minute or two (like planetary observing) the features occasionally pop into sharpness. I have genuinely been able to use magnifications toward the 3mm end on the moon (533x) from time to time. It’s even possible to track manually with some success.

68 Flamsteed P – Success (or so I thought)

Flamsteed was easy enough to find, being a large crater near to Grimaldi. My references suggested that Flamsteed P was a small white speck just ‘north’ of two small craters, Flamsteed D&K. There was a small black dot with a P next to it on the Rukl maps I have and this corresponded with a small white speck observed on the night. The description in the Lunar 100 list is of a “Proposed young volcanic crater; Surveyor 1 landing site”, which pretty much seemed to check out. What I now realise after having actually studied the maps in the daylight is that the small black dot represented not the point of interest but the centre of the ‘sub crater’ Flamsteed P!! Flamsteed P is a large, but low elevation, ‘crater wall’ within the main crater wall so I have not seen this one after all! (‘Fail to plan, plan to fail’ I hear you all say!!).

83 Plato Craterlets – Success

I have never managed to observe at the right time to really catch the type of lighting required to give a better chance of seeing these craters well. They are always tricky when there is a fair amount of light on them and tonight four craters were just visible in the occasional good seeing.

86 Prinz Rilles** - Success – new object

I have tried several times to see this feature but failed due to timing and poor seeing. Tonight it was very easy to see a number of rilles emerging south from the crater as it was quite close to the terminator. I suspect the night before would have been even better but really glad to see this tonight.

13 Gassendi - Success

A superb, large and feature filled crater. The basin floor features were very pronounced tonight and various cracked areas were seen as well as the central peaks. This is the best, most detailed view I have ever had of Gassendi.

30 Schiller - Success

I cannot really say why, but this is always a favourite of mine. Such a well formed and sharply defined crater. Tonight I could easily see the small (although not as small as Plato’s) craterlet on the floor of the main crater. This crater is another one that is large, distinctive and easy to find and acts as a great marker when ‘crater hopping’.

39 Shickard - Success

Shickard was a really beautiful sight tonight as it crept out of the terminator shadow. Numerous floor craters seen contrasting with the dark crater floor, which seemed slightly domed, looked a lot like pock marks. For some reason I was reminded of the back of a Surinam Toad.

49 Gruithuisen Delta & Gamma - Success

Both of these large volcanic domes were very obvious in these lighting conditions and with good seeing.

42 Marius Domes - Success

These pimples were half in and half out of the shadow, showing excellent detail and high numbers of small volcanic domes. I have previously described these as being like ‘whole peppercorns under ladies tights’ and tonight this simile seems especially appropriate. Stunning detail.

54 Hippalus Rilles - Success

This is an excellent feature with a number of rilles seen. To my eyes, this resembles a claw scrape across the landscape by a giant cat.

59 Schiller-Zucchius Basin ** - Success – new object

Initially this was tricky to see but as I watched, the large basin became obvious. It stretches south east from Schiller, touching the outer edge of Zucchius and then forms a large circular area. There seemed to be a further concentric ring within the outer ring. This must have been some impact!

43 Wargentin - Success

Definitely seen but it was only just visible as it was still mainly in shadow.

9 Clavius - Success

Always a favourite and very useful as a guidepost to find other features.

17 Schroter's Valley - Success

Fabulous area and being just in from the terminator it was superbly lit tonight. This is one of my favourite areas of the moon, with the valley (a huge rille), the extremely bright crater Aristarchus and the hilly terrain around the whole section, known as Aristarchus Plateau.

11 Aristarchus – Success

See Schroter’s Valley above.

22 Aristarchus Plateau – Success

See Schroter’s Valley above.

62 Rumker Hills - Success

Just half in and half out of the shadow, looking massive I had very detailed views of this large mound of material. I’d love to stand at the foot of this, sit and have a sandwich (OK, maybe a suck on my baby food) and look back at the Earth.

98 – Imbrium Lava Flows – Fail

Although I could not see this feature as it requires extreme side lighting, I did get a proper fix on the location of the most obvious. I will get them next time the phase is right!

After the session on Luna, I then turned to my usual favourite constellation, that of Orion. It’s always nice to see this area in the scope but it really was a little subdued tonight due to the brightness of moonshine. As a result I decided to have a look at a few doubles and a couple of open clusters. The seeing as already mentioned was actually pretty good and the Trapezium was an obvious target. I managed to see all six of the main stars with my 12.5mm BGO at 128x magnification. Averted vision was required for F and E could be seen directly. Both were quite faint though even with the 12” dob. This is another target where the seeing is intermittently good and if you watch for a while the detail emerges (I really cannot wait to get my equatorial platform made so I can stare for longer without having to shunt the ‘scope).

Another of my favourite multiple systems in Orion is Sigma Orionis. This forms the L shape at the bottom of Orion’s belt and is an easy system to split into four stars. All four components were readily split. This is a really excellent visual spectacle with all four stars of different sizes and colours strung in a line and if you have never seen it then have a look – it’s impressive! The 12.5mm BGO was again the weapon of choice for this target. The bright blue star at the bottom right of Orion is Rigel and this is an easy double with a very bright primary and small, quite dim secondary.

Mizar and Alcor form a naked eye double, at the ‘elbow’ in the handle of the Plough asterism in Ursa Major. Mizar is itself an easily split double. I often look at this famous double and tonight when framed in the 18mm BGO at 89x magnification, it is probably the best I have ever seen it. Just fitting nicely within the field, all objects were very sharp and clean looking.

The final double tonight was actually the first (but I forgot to mention it!). This is Polaris in Ursa Minor, the Pole Star. Since this never moves to all intents and purposes, I use it to set up my Telrad and optical finders when starting the evening off. It is a good star for a star test too for the same reason. The dim secondary is easily split from the bright primary star even at quite low magnifications (easily done at 89x).

As the moon was beginning to edge over house I decided to have a search for a couple of open clusters with the binoculars . The conditions were still pretty good but moonshine creates problems with clusters, making the fainter stars less obvious (or invisible). The first was the Beehive Cluster Messier 44 in the constellation of Cancer. At 15x, the cluster stood out well and was well framed and shown in good context with it’s surrounding star field.

Canis Major finally cleared the tree in my neighbour’s garden and I then had a quick look at the open cluster Messier 41. This was my first look at this Messier this year and rather nice in the 15x70s. Will look in the scope at this next session or when the moon has gone. While here and for a bit of a laugh to be honest, I thought I would have a try at splitting Sirius, the brightest star in the sky. It was pretty high (for Sirius) by this point and I had a decent chance as the seeing was still OK. Unfortunately, even with the nagler 6-3mm zoom and an Oiii filter I read this can sometimes help) there was nothing doing. I might try and make a mask for the eyepiece and see how this goes – I’ll report back in due course.

The final target for the night was the open cluster Messier 50 in Monoceros. This was a new Messier object for me and shockingly the first time I have taken the time to find the constellation in which it sits! With the moon still up and some of the Canis Major guide stars being behind trees, it was a little tricky to find but did so in the end using a point about a third of the way along a line from Sirius to Procyon in Canis Minor. The cluster seemed to be somewhat arrow shaped in general and with a small number of quite bright stars. Quite a large cluster, looking best in the 22mm Panoptic at 73x. I'll visit this one again when Luna is not spoiling things and it’s not the end of a long but enjoyable session!

Hope you all enjoy some clear nights soon.

Cheers

Shane

[Patbloke]

That's a quality report!

Very interesting, I think I need to start noting like that... nice one.

[Moonshane]

believe me, my notebook was nothing like it!! the odd scrawled word and it triggers the memory although I have to do it soon after the event or I forget. if there's a particularly complex thing then I make notes straight away in detail at the time or I've no chance!

[perrin6]

Great report Shane! Must start the lunar 100 myself soon. RE: M50 in Monoceros. Have you seen M46 yet it's a lovely cluster with a bright planetary nebula in it. It's a bit low and 11.5 deg SE of M50, in Puppis. I managed to glimpse the PN in my ZS66 when the air was particularly transparent. It looked grand in my old 8 inch years ago and in a 12 inch it should be a beaut.

[Doc]

Amazing work Shane. You observe very similar to me, I make rough but detailed notes on the laptop and then write up the next day, it works well.

Flamsteed P according to VMA is the whole partially buried crater that is 61 miles in diameter and contains all the craters you mention.

Below is my entry for this object.

Number 68 Flamsteed P

The crater Flamsteed marks the top point of an equilateral triangle with the other points denoted by Flamsteed K and Flamsteed D. At first I thought Flamsteed K was the crater I was looking for but it is not, I now know that Flamsteed P is 61 miles in diameter and is a lava filled crater, with only a few outer walls remaining, I could now see it with the 12.5 mm ortho. The craters Flamsteed, Flamsteed K and Flamsteed D are all within the walls that make up Flamsteed P. I counted six breaks in the wall, I really enjoyed observing this one. Also Surveyor 1 landed not far from Flamsteed K. Surveyor 1 was the first lunar lander in the American Surveyor program that explored the Moon. The program was managed by the NASA Jet Propulsion Laboratory, utilizing spacecraft designed and built by Hughes Aircraft. It was launched May 30, 1966 and landed on June 2, 1966

It took a total of 11,237 images that were transmitted to Earth. The successful soft landing in the Ocean of Storms was the first ever by the U.S. on an extraterrestrial body, and came just four months after the landing of the Soviet Luna 9 mission. With the help of VMA I could see the actual area that this fantastic event occured, to say I was humbled was an understatement.

[Moonshane]

cheers Mick - I'll be printing off your notes next time (or more accurately before) I observe this crater!!

I enjoy writing up my notes almost as much as observing. I try to write them like you do, to help both myself and others remember and learn a little but. The problem is sometimes that when you have a cracking night it takes an age to write everything up! I must start trying to sketch but I am really rubbish with a pencil.

[Hypernova]

That's another superb report Shane, it sounds like you had a great night on Luna and even a bit of deep sky thrown in despite the moonlight

I am curious though why you chose the 12" f/5.3 over the 6" f/11 for lunar viewing I would have though the 6" would provide superior views of the moon compared to the faster 'scope despite its aperture disadvantage.

[Moonshane]

you hit the nail with you last comment Tom. I find that for some reason on the moon, the 12" 5.3 (with the higher resolution coming from aperture) is better than the 6" f11. don't get me wrong though the 6" is still very very good. The 6" is far better on planets though and it's about even on doubles although I actually feel the 12" shades that too. I am starting to conclude that the 6" really is (as the blurb says I suppose) a specialist planetary scope and that's where it excels. it is still good on double stars but here again I think aperture resolution helps.

I also planned a general look about too and on the whole the 12" is more stable and enjoyable to use than the 6" and blows it away as you'd expect on fainter targets.

Some of this may change when I complete my equatorial platform(s) will be interesting to see!

[Hypernova]

So is it them "aperture rules" then on objects other than the planets regardless of f/ratio?

Just going on though, I have never found my dob to be that good on double stars. I have always tried to maintain it in as good collimation as I can, I suppose I have been unlucky and have been plagued by bad seeing all this time. I still think though I am not getting good collimation with the cheshire due to that brass ring pushing the crosshairs to one side

[Moonshane]

there's no doubt in my mind that for the 'nicest' view of double stars a refractor will win generally. stars are a bit tighter and 'cleaner' than with a newt. but it's a balancing act between sharp and clean and larger aperture as the latter can allow certain objects to be split that a smaller refractor will not even though the view is not as lovely. this is my experience anyway. it will be interesting to see what the experts think of our collimation at SGL6 - I hope to ask when we are there and maybe get someone to show me a star test too if there's time. I am also interested in how the 8.5 f8 mirror set I have on the bookshelf performs - will be making a temporary OTA for this soon and will test against the 6" f11.

collimation is a weird one as I think I have it sussed and then someone comes along with some comment or other and makes me uncertain! for visual observing it's important but never as critical as for imaging and I bet you are doing OK. personally I have never got on with my proper Cheshire and prefer one of those cheap ones that often come free with scopes in conjunction with a collicap. I have now read that a collicap is not the right thing to be sorting the secondary out with (hence my comment above!!).

[perrin6]

there's no doubt in my mind that for the 'nicest' view of double stars a refractor will win generally. stars are a bit tighter and 'cleaner' than with a newt. but it's a balancing act between sharp and clean and larger aperture as the latter can allow certain objects to be split that a smaller refractor will not even though the view is not as lovely. (hence my comment above!!).

Yes Shane, I prefer the view of doubles in my little 66mm frac than my 13 inch. Eg Castor, Algenib (Gam Leo), Gam Delphinus etc, they look like perfect round car headlights in the 66 at X100 but in the other, look like Photon torpedos such as the Klingon ones in Star trek the motion picture ! However, I still enjoy catching glimpses of sub-arc second doubles in the 13" as the seeing momentarily clears - they make make me go 'ooh'. And of course there are a lot of very close doubles for large apertures although Stellarium isn't much good for finding them (unless I havn't worked out how to) , Redshift 4 shows all doubles with a line through them so you know which ones to check out. Stellarium is good for data and confirming what you thought you saw though.

[perrin6]

collimation is a weird one as I think I have it sussed and then someone comes along with some comment or other and makes me uncertain! for visual observing it's important but never as critical as for imaging and I bet you are doing OK. personally I have never got on with my proper Cheshire and prefer one of those cheap ones that often come free with scopes in conjunction with a collicap. I have now read that a collicap is not the right thing to be sorting the secondary out with (hence my comment above!!).

I use a cheshire and I'm not sure I use it correctly. When peering through it I line everything up with the crosshairs which spread out as I cant focus on them because they are too close to my eye, but am not convinced the scope is properly aligned when I look at star images. Dont know whats going on there, perhaps my focuser isn't quite perpendicular to the telescope tube, as it's home made.

[Moonshane]

Yes Shane, I prefer the view of doubles in my little 66mm frac than my 13 inch. Eg Castor, Algenib (Gam Leo), Gam Delphinus etc, they look like perfect round car headlights in the 66 at X100 but in the other, look like Photon torpedos such as the Klingon ones in Star trek the motion picture ! However, I still enjoy catching glimpses of sub-arc second doubles in the 13" as the seeing momentarily clears - they make make me go 'ooh'. And of course there are a lot of very close doubles for large apertures although Stellarium isn't much good for finding them (unless I havn't worked out how to) , Redshift 4 shows all doubles with a line through them so you know which ones to check out. Stellarium is good for data and confirming what you thought you saw though.

spot on Alan I think. I can see me eventually buying another refractor for double stars but not sure yet; I just love the plonk, cool and play nature of my dobs. that said, I am finding that in the 12" if I drop to the 18mm BGO (89x) the stars look beautiful. Maybe I just need to find the balance and this is one of the reasons I got the 15mm TV Plossl. As we all know, one scope does not fit all

[Moonshane]

I use a cheshire and I'm not sure I use it correctly. When peering through it I line everything up with the crosshairs which spread out as I cant focus on them because they are too close to my eye, but am not convinced the scope is properly aligned when I look at star images. Dont know whats going on there, perhaps my focuser isn't quite perpendicular to the telescope tube, as it's home made.

me neither! one of the things I am hoping for at SGL6 is someone during the day with a bit of time to watch me collimate from scratch (I'll put it well out) and see if they can confirm I am 'doing it right' - maybe we should ask for a collimation training session during the day??

[perrin6]

maybe we should ask for a collimation training session during the day??

Excellent idea. I wonder who are the experts at this (and how do you tell them from those who just think they're an expert!)

[Moonshane]

ha ha too true too true!

[Hypernova]

An excellent idea, I am sure pretty much all of us could do with a crash course in collimation, even the "pros"

I think I would definitely benefit from someone showing me the proper way to collimate.

[Moonshane]

I'll put a request n the thread.

[perrin6]

I just love the plonk, cool and play nature of my dobs.

Yes, and since getting my zs 66 I now realise how much easier my dob is to use. With the frac, mounted on a reasonably good photo tripod I have to keep changing the tripod's height, I'm rarely comfortable as I have to be careful where I put my feet so as not to tread on the tripod legs and cause the image to wobble as it does easily, and the image wont stay still while focusing.

With the dob it's rock steady at all times, you'll notice that when you build your truss-tube, having the balance point way back and on a low rocker box, probably better than your present scopes in this respect I imagine. And the movement of the scopes position seems easier and less fiddly than a refractor, although I can't quite describe why.

[Moonshane]

totally agree Alan. My 12" is superbly balanced and all the weight at the bottom - very smooth. perhaps I should rephrase that (oooh Matron)

the 6" is very tall and spindly and although still excellent it's a lot more 'bouncy'. This is one of the reasons I am making an EQ platform as the less I have to move the scope the better.