Log: 05.30.05 – 9 -11:10 pm EDST

Location: Driftway Observing Green

Seeing: poor

Transparency: average

Moon: not present.

Equipment used: Obsession 15, Denkmeier standard binoviewer with Denk 21 mm eyepieces and , OCS, and double arm Power X switch delivers approximately 115X, 168X, and 208X from the single pair of eyepieces – but I need to test those, as well as the true FOV

Objects: Jupiter, M3, M81, M82, M51, M13, M97, Gamma Leonis, Polaris, Cor Caroli, Double Double, M57

Weather: temp 55-60, dewing significant - forecast had been for clouds and possible thunderstorms – had about 70% clear when I went out with clouds off to north – varied down to 50% or less and up to 90% during observing.

Highlights – how easy it is to find things with this size scope - the desirability of tracking - objects are not like their photos, but this scope raises observing to a whole new level of reality . - M13, M51, M57 Cor Caroli (this was just a sightseeing night – no real study – just getting quick impressions of different objects)

I followed Dave Kriege's directions and on this first real night of observing with the 15-inch Obsession I did not use either the ServoCAT tracking or the Argo Navis computer to find things – and I’m glad. The experience gave me a better feel for the scope and I came away with four basic impressions:

1. Messier objects and other relatively bright objects are easy to find because they look like the objects. This ease of finding with nothing but the Telrad was unanticipated by me because I had never put these two things together, obvious as they are. That is, I knew things would look mor like the real object and be brighter - but I had never considered ow much easier that would make finding an object. I’m used to a deep sky object only being a crude imitation of what you see in photos.
2. I thought that I wanted to get the Argo Navis functioning next because I needed it to find objects. I’m sure it will be very useful as I move on to fainter objects – but right now it is more important to have the ServoCAT working so I can track objects. The highest power used in this session was about 208, but at that power things were moving out of view pretty quickly. (My guess is the practical FOV is about 15-20 minutes using the Denk 21s in that mode.)
3. The views of globular clusters were, in my opinion, better than their photos. Galaxies can’t compare with their photos, but the view is a significant improvement over an 8-inch SCT or 6-inch reflector. Planetary nebulae are somewhere in between. You are lacking the color the photos provide, but aside from that the views were getting close to what you see in photographs. However – for me there is a tremendously heightened sense of realism when viewing anything with the 15-inch You simply can’t beat being there – a live performance , whether it be a baseball game, concert, or a Shakespeare play – simply adds a dimension that no recording, photograph, video or movie can match, Don’t get me wrong – these others are events in themselves with their own special appeal – but for me nothing compares with being there and the 15-inch raises “being there” to a new height. . That said, I’m not at all sure that it would impress a novice observer who had not used other scopes and who had expected things to look like their photographs.
4. The moons of Jupiter look like moons – they have visible discs – as opposed to stars. I wasn’t prepared for this.

Equipment issues:

1. On the Power X switch – a. Left (logo side) in = low power b. Right in = medium power c. Both out= high power

2. Power x switch in current position interfere with left focusing knob somewhat – may want to adjust. 3. Wish I had spent more time leveling ground – ran into issues with telescope not turning 360 easily –seemed to hit some high ground – and with chair being balanced comfortably. 4. Telrad dewing has to be tackled as well as all the electrical problems.

Chronology

9:01 – 63 degrees – lot of twilight – collimation very easy and fast – about a minute – Telrad required only miniscule adjustment to get it on target – Jupiter – moons look big – I had fan going , so I turned it off and it may have made a slight improvement- highest power the left-hand moon is two thirds of the way from right edge. In Starry Nights I measure this spread as about 9 minutes – so what I would consider the usable field at this power is about 14 minutes. (I’m sure it’s larger, but . . .)

9:17 – Arcturus is huge which says to me seeing is pretty bad – I see Cor Caroli and I know about halfway between Cor Caroli and Arcturus, I’ll find M3 – I found it pretty easily – in the twilight still a ghost of what it will be under dark skies, I’m sure – pretty washed out – it does resolve well at highest power, though – also, it is too high for my current observing chair, but fine while standing flatfooted – it is at 75 degrees according to Starry Nights, so that’s in keeping with earlier estimates about the chair.

9:29 – Decided to split Gamma Leonis (Algeiba ) just above the trees to the west - ran into a problem of moving telescope on uneven ground – wish I had spent more time trying to level this area - Splits easily at lowest power – primary significantly brighter – seems like a relationship of 2 –4 or maybe 3 and 5 and the secondary seems to have a little more color to it going towards orange – the primary is yellow-white, view gets worse even at medium power – indication of poor seeing – ok, actual magnitudes are 2.6 and 3.8 - Belmont Society sees it as “twin yellow suns. But in a 6-inch reflector it can show up as a pair of pale oranges.” See sketch: http://www.belmontnc.4dw.net/dblstr-sket.htm - In “Turn Left at Orion” the primary is described as “golden yellow” while “some people” see the secondary “as orange.”

9:37 – Back to Jupiter – I’ll play my game of trying to identify the moons – furthest to the left is the smallest – might be Io – moon right next to it is maybe just a fraction brighter – the brightest is the first one to the east – also largest – furthest out one seems a little dimmer, but also larger than the two to the left. Here’s what Starry Nights (SN) shows:

Europa –5.72 , radius 1568 KM : Io 5.45 1814 : Jupiter : Ganymede 5.04, 2630 : Callisto 6.09 2399

So – the left is indeed the smallest, the moon right next to it is a fraction brighter – Ganymede is indeed the largest and brightest – but Callisto is the dimmest and while I said it was dimmer I don’t think I thought it was that dim. But I said it was larger than the two to the left and I was right on that score, so what’s the point here? The point is with the 8-inch scope I would not even have attempted to identify size – in the 15-inch I see the moons, not as dim stars, but as discs and able to evaluate them correctly. (I’ve played this game with the 8-inch, but evaluated them only by apparent brightness)

9:40 – Ok, that was a wow! I’m not using any star charts – just working from memory – I pointed in general area of M13, panned around a little bit and bam – couldn’t miss it - my impression here was that of a sky rocket moving up and to the right (eastward?) at highest power an awful lot of stars resolve – looks very much like a photograph, except better – really hard to believe – there’s a new dimension of reality there that’s really hard to define –certainly globular clusters like M13 really come into their own – 100X gives a nice context to it – like a rocket going up and to the right with a scattering of half a dozen stars behind it that look like sparks from its exhaust. ( muxh darker skies now than when I looked at M3)

9:53 – Stopped for a moment at Polaris – don’t think it will make a good alignment star for Argo Navis as I had assumed it would– kind of low, not that easy to find in Telrad with all the light pollution over there, plus dew – nice and white and it’s little companion is blue and at 10 –10:30 on the clock

9:56 – Amazed at how easy it is to find things with just the Telrad and scanning – I assume it’s because things look like what they are supposed to look like – like M81 and M82 – to much light pollution in that section of sky and only at about altitude 45 – but I did find them – I did not stay to look, however – I’ll save them for a time when they’re better positioned. (Actual altitude was about 50 according to SN)

10:00 – dew has about done in Telrad – did find Cor Caroli pretty easily – very nice pair – stars fairly easily matched in color, although I would say the secondary paler, almost violet, primary is blue/white - (hmmm – “Turn Left . . . “ has the color different – “”The primary is bluish white, while the color of its companion is usually described as yellow or orange.” It does say, however, that the color shading is “subtle.” Uh huh.)

10:08 – well , it took a lot of scanning around because the Telrad is pretty fogged up – but I found M51 – first impression is a pair of eyes looking at you – you can make out some of the spiral, but mostly it looks nebulous – the two cores are obvious – also I am standing as tall as I can – couldn’t look at anything higher without some sort of step (actual altitude 82 degrees – so that’s fine – Dobsonian won’t perform well pointed much higher) – been using lowest power – went to medium power and immediately saw the star which is at 12 o’clock in the larger galaxy embedded in one of its arms – a foreground star? = many years ago I saw it and thought it was a nova – once more these things look like what they are supposed to look like – you move from little fuzzies to something real – definitely I feel like I’m looking at spiral arms here (highest power) most prominent arm goes between two galaxies – comes from about the 3 o’clock position to 7 – quite separated from the core of the galaxy – lot of dark between core and arms – look forward to getting Servocat working – I would like it better if I could just get it centered and have it stay there – hard to explain how this is so much more real at this level – it’s not what I thought and yet it’s more than I thought – quite a few clouds moving in from the northeast – looking at the Telrad and if the Telrad had one more ring it would be touching the last star in the Big Dipper handle (when I have M51 in view) (For a “quick tour” night I spent quite a bit of time on M51 – fascinating.)

For the record – using SN here’s what M51 really looks like.

Here’s an approximation of what I remember M51 looking like in a typical 6-to-8 inch – honestly, you can nurse details out of such a view, but you need to work at it and have a lot of imagination.

And this is what I remember from my first look at it in the 15 inch - though the background was darker.

Obviously this last doesn’t match the photograph – but when you know you are seeing the real thing – when you understand you are looking at 100 billion stars that are about 20-40 million light years from us – when you know this is two huge stellar systems in collision and one is tearing stars from the other . . . it is an experience that stays with you more than the best photograph. You simply can’t beat being there. In a way, a good comparison would be going to a baseball game. Yes, while in the stands you can not see the action from several different angles – as you can on TV – and you can’t see the expressions on the players faces. But again, there is something about being there, in the park, as it is happening – that adds a special dimension that no photograph, no matter how good, can ever capture.

10:22 – Found M97 – hardly any fiddling at all – owls eyes are going in and out on me - very ghostly – not that impressive – a little more transparency and less light pollution would help

10:25 – need to put some white tape on observing chair – keep running into it

10:29 – Bingo! M3 – getting good at this! Such a tight little ball compared with M13 – doesn’t resolve as easily as M13 – at lowest power it starts to resolve – medium power – that makes a difference – still the core won’t resolve as easily – at highest power resolves much better – need a towel to dry dew off things

Looking at Jupiter – I may be wrong, but there’s the “great pale spot “– just jumped out at me in a moment of clarity – just west of the center – better than I’ve ever seen before in my life – but only had that one moment of clarity despite looking for quite a while longer – it’s eastern edge was almost touching the center line of the planet – this is confirmed by SN

10:49 – Be interesting to know exactly what the altitude of Jupiter is now (38 degrees) – this is extremely comfortable sitting at this height, observing it – also with the eye relief on the Denks I don’t have to put my eyes right down on them – feels more natural – Jupiter is a bit bright – could use a filter here,

Double-double - there it is first try – at lowest power isn’t splitting it – not that high up in altitude – actually 44 degrees – yet I could not split it which is an indication of how poor the seeing is

Wow – now that’s impressive – M57 – the Ring Nebulae – very little searching – but oh, it’s beautiful, even at the lowest power – in high power it looks even better – now I do not see a central star – though I don’t expect to – but it looks like the Ring Nebulae – one thing that strikes me is it’s more oval than I remember and more irregular – medium power shows it off nicely – star just to the east of it, right on its edge, probably not on the limiting mag of the scope – but getting down there, (Pictures confirm it is an oval and irregular – the star referenced may have been 12th mag, but not sure. It seemed fainter to me, so I’m not positive which one I was seeing.

11:08 – One more look at M13 – really something - finder all fogged up – clouds coming over – getting time to go in. At highest power it comes close to filling the eyepiece.

At 11:11 I began packing everything up and taking it in – probably should have left some stuff out, but…helluva lot of work to do on developing a system here – finished at 11:32, so it took about 21 minutes. Again, biggest frustration was screwing Denks into “safes.” Seems like a great idea, but I feel I end up fumbling with them more than they;re worth.