Jims Orion XT10 Astronomy Blog

I have now finished my latest review article about the Orion Dual-Speed Low-Profile Crayford Focuser that I got for my XT10i telescope recently. At the same time I also got the Orion AccuFocus Motorised Focuser to provide vibration-free fine focusing of my telescope. Both these are detailed in the XT10 Telescope Modifications section of my web site.

Orion Dual-Speed Low-Profile Crayford Focuser plus AccuFocus Motorised Focuser

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Listed in Modifications, XT10, XT10 Assembly

I’ve just finished a new article on the main web site in the Collimation section describing How to collimate the Primary Mirror using the Barlowed Laser Technique. Of course this requires a Barlow Lens and a Laser Collimator for this method to be used, but the page also provides links to some excellent resources detailing collimation methods.

Barlowed Laser method of collimation

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Listed in Collimation, XT10

You may have read one of my recent posts reviewing the Adler Optik Jupiter 20×80 Giant Observation Binoculars.

With binoculars of this size, they are quite heavy and suitable methods of supporting them is a must. Not only will your arms buckle under the weight after a while, but they just cannot hold the binos steady enough, and stars will just be a constant blurry motion.

While a good sturdy Tripod is the simplest method, why not consider one of the following alternatives, from the sublime to the ridiculous!

All of these are homemade chairs, and a couple of these sites will supply the chairs as kits for purchase.

• The EZ Gazer - Star Gazing Chair - Binocular Viewing Mount (see photo above)
  
• STARGEEZER PRODUCTS PRESENTS The Couch - Potato Telescope
• Redneck Astronomy Bino Chair (RAC 1000)
• Gary’s Motorized Big Binocular Chair - by Gary Honis
• The Making Of Voyager - Wayne Schmidt’s Motorized Binocular Chair - you gotta see this!

Thanks goes to Walt Reil at Central Coast Astronomical Society for the above fascinating links. You can see more pictures of Tom Frey’s EZ Gazer Astro Lounger Chair in use at this CCAS Star Parties page.

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Listed in Observing

With clear skies gradually returning now that the colder evenings of autumn are upon us I have been enjoying the views of the heavens while walking my trusty dog Ben on the public footpath in fields at the back of our house. For stargazing I suppose I’m lucky that I can be out in the complete darkness of the fields in just 2 minutes. While he chases out rabbits I crane my neck upwards to look at the Milky Way, and Ben wonders why I’m walking so slowly, then impatiently stops and runs back as if to say “What have you found?“.

It is now nearly a full year since I first got my Orion Skyquest XT10i newtonian reflector and I have learnt a good deal about astronomy, and come to appreciate the splendour of the universe even more. A year ago I had not really “seen” the Milky Way properly. Of course I knew it was there, but I suppose I never really understood which constellations it passes through, and generally mistook what I was seeing for very light haze or cloud. Now when the sky is clear and bright enough I can easily make out its shape as it passes overhead through Cygnus and Cassiopeia. I think its fascinating that we are inside this galaxy looking outwards through its spiralling arms into deep space, and that there are so many millions of stars in our own galaxy, that they just look like a misty haze!

Last night while looking through the telescope my wife came out to me and for just the second time since getting my scope she looked through it and was amazed at the beauty of the Pleiades and then the double-cluster between Perseus and Cassiopeia, saying “My god, there’s thousands of stars!“, two sights I knew would be dead quick to locate and show her before she got too cold or bored. She seemed truly astounded.

My mission last night was to try and see the California Nebula, recommended in the October edition of Sky at Night magazine. Big, red and shaped like a foot, NGC1499 next to Xi Persei and 12 degrees north of the Pleiades is named after the USA state it is supposed to look like. Apparently from a dark site it is possible to see this quite large nebula (think 3 Moons long) as a misty patch with your eyes, and with binoculars, or with a low-power eyepiece in the telescope (use low-power otherwise you’ll be looking straight through it, rather than at it). Well try as I might I just could not see it. My eyes were quite well dark adapted, and I tried to see California with my 20×80 binos and with my 38mm SWA eyepiece, and even using my recently purchased Baader UHC-S Filter with my Hyperion 13mm and 25mm Plossl. I tried for a good half-hour to make out what I thought should be a fairly obvious night-time feature, but to no avail. In comparison I was pleased to be able to make out M37 tonight, the dimmest of the clusters in Auriga, and one I was unable to see on a previous occasion when there was a full Moon. Oh well, you win some, you lose some! I suppose my backyard is simply not dark enough?

Have you been able to see the California Nebula? - Did you find it difficult?

To make up for the disappointment of not seeing NGC1499, I focused on the Andromeda galaxy, and took in its huge size, and pondered on the possibility of a little planet somewhere in the Andromeda galaxy with some guy looking up and out towards their nearest neighbour called The Milky Way. A theoretical “dopple-ganger”!

At about 1.00am I noticed that Orion was rising above the house behind ours, and I watched patiently for my first chance this autumn to view the great Orion Nebula. As it came into view and I focused carefully to get the best image I was transported back in time a year to the very first night, my “first light” when after I had finished building my scope I eagerly took it outside and lined it up on Orion.

Welcome back Orion.

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Darkness is what matters in Astronomy. Stars shining brightly, painted on the black canvas of space.

And there’s nothing spoils the view more than having a grey or washed out view through your telescope.

One form of light pollution is of course the overhead washing out of the sky due to street lights en-masse shining up into the atmosphere, which is then reflected back down to earth by water-vapour in the air. Filters are used to help astronomers with this kind of light pollution, and when it is impractical to visit a location that is away from the source of the lights. When the full Moon shines high in the sky, you instead choose brighter objects to observe, such as the planets and more dominant stars and constellations. Of course you can take time instead to appreciate the beauty of the Moon herself.

The other form of light pollution that causes bad contrast in telescopes which we do have a little more control over, is stray, unwanted light coming into the end of the telescope at an angle from nearby domestic lighting; be that from streetlights, decorative garden or patio lighting, house lights, the next door neighbours pesky football pitch floodlight, or the gentler but still invasive light from the Moon.

Well at least the Moon has every right to be there.

You can close curtains or turn off un-necessary house lights, garden lights, and have a friendly word with the neighbour. You can even write to the local council to see if they will do something about the nearest streetlamps. Or you can purchase a “dark-cap” or “dew-cap” to wrap around the end of the telescope to help prevent strong side-lighting. I often use a large patio-table umbrella opened up and laid on its side to shield me from a particularly annoying streetlight.

The main issue here is that the interior surface of the telescope tube, even when painted matt black by the manufacturer, still has a degree of reflectivity that causes the light to scatter and bounce its way down the tube, and into the eyepiece, where it adds a subtle lightening of the background, and this reduces the resolution and contrast, and therefore the enjoyment of observing stars, and can make viewing deep-sky objects far more difficult.

A very effective and permanent solution to employ with open tube telescopes such as Newtonians, is the addition of materials with low light reflectivity to the inside surface of the telescope tube, and this procedure is known as “flocking”.

Read my latest article on How to flock the interior of the Orion Skyquest XT10 newtonian reflector OTA tube.

In this article I describe how to add black flocking material (ProtoStar Hi-Tack Flocking Sheets) to the interior of my Orion XT10 newtonian reflector telescope tube to increase the contrast when observing the night sky.

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Listed in Modifications

Tonights viewing was an attempt to obtain some better webcam footage of Jupiter. As usual though, it was very low in the sky, and I have only a short timeslot due to gaps between buildings. In fact I stood the XT10 on top of my patio dining table to give it sufficient height to see over the garage rooftop. Aligning the scope when standing precariously balanced on the chairs and/or table is not very good, and it took ages to get everything set up well enough to start capturing Jupiter.

Managed to get some short captures using K3CCDTools at prime focus, and reasonably sharp focus thanks to the new dual-speed crayford, but when attempting to get Barlowed capture it was incredibly blurry from bad seeing, and with probably only 15 minutes til Jupiter set below the rooftops. I will see whether K3CCD or Registax can pull anything better from these captures.

Next took some new Webcam footage of the Moon, something I have not done for quite a while. Moon is 1 day from full, and very bright tonight in an almost cloudless sky. Seeing is giving the classic underwater effect on the Moon’s surface. This time I have not used the moon filter, but instead adjusted the gain right down, and FPS up, so as to give a nicely dim image, with plenty of detail, and as well-focused as I could. Again the dual-speed Crayford is doing a fantastic job of focusing very finely. Got several passes captured to video which can be worked in Registax later on.

Did some extensive experimentation of video capture settings with the webcam to see what magnitude of stars the webcam could pull out. Some of the primary stars in Cassiopeia and Auriga were nice and bright with diffraction spikes clearly visible on the bright stars, and still picking up fainter stars probably down to approx 8th or 9th Mag. For the faintest 5fps was required with absolutely minimum (slowest) shutter speed, and almost max gain, max contrast, and centre brightness. Monochrome image, and picture enhancement off. The Pleiades was also a good test, clearly able to capture the brighter stars, although I’m beginning to realise that the field of view of the webcam is rather restricted, and capturing the whole of the Pleiades is impossible, it only manages to get 2 or 3 of the seven sisters at once. So while this might be hopeful for getting images of bright starfields, it seems like I now need a new lens for the webcam to give a wider field of view.

Finished experimenting with the webcam and decided to just do some normal observing. Tonight the sky is very washed out by the almost full Moon, so it was interesting to see how deeply I would be able to see using the SWA 38mm, and Hyperion 13mm EP’s, in Perseus, around Mirphak. Comparing against Stellarium I could make out down to about 11th mag, which I thought was quite good, and once again proves not only how good the XT10 is at bagging as much light as possible, but also that first impressions of a poor night sky are usually proved wrong, and that it is worthwhile getting the scope out. In Auriga I hunted out M36 and M38 successfully, but was unable to view M37, which the Moon was overpowering, and my star-hoppping was unable to locate.

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Listed in Astrophotography, Observing

Two things of note in this post, both of which are related to Skyquest XT modifications - well one is specifically for Orion Skyquest XT scopes, while the other could be of use for most solid tube-type dobsonian mounted telescopes.

1. I’ve added a new page to the mods section detailing the creation of cheap, simple, easy-to-make weights that can be used to counter-balance the telescope altitude adjustment. In fact I made these counter-balance weights quite a long time ago, but didn’t really consider them particularly exciting! However I read a forum post the other day where folk were asking how other people achieved balance for their Dobsonian mounted tube telescopes. The page is: How to make counter-balance weights for a dobsonian telescope.
2. Just last week I received my latest purchase; a Low-Profile Dual-Speed Crayford Focuser from Orion USA, (see here) complete with an AccuFocus Electronic Focuser also from Orion. These are very nice well-engineered pieces of kit, which I have just finished installing to my Orion XT10i. I’ve taken tons of pics of these two items, and very soon I will create another page for my Mods section reviewing them, comparing the old and new Crayfords and showing the installation of a) the new Crayford focuser, and b) the AccuFocus electronic motorised focuser onto i) the old single-speed crayford focuser, and of course, ii) the new dual-speed crayford. In fact the AccuFocus can also be installed on older rack-and-pinion style focusers.

A quick try-out last night with the XT10i and everything installed, provided excellent pin-point fine-adjustment of focus, without any jarring/vibrating of the scope as is usually the case when focusing by hand.

So keep an eye out for this if you’re interesting. I’ll announce it here in my blog.

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Listed in Modifications, XT10

Tonight has been quite a satisfying nights viewing. Just in my back yard which has street lamps shining in from a couple of directions, but I put my big patio umbrella up to shield the light, and I’ve also recently flocked the interior of the XT10, which makes a noticeable difference to the view contrast, and I have my new Baader UHC-S Filter which in a previous post I couldn’t be sure of what difference it made. Well tonight was a much better, clearer, brighter night, and the filter does indeed make the sky blacker, so it must be cutting out some of the white light glow from the mercury streetlamps.

The objects I viewed were:-

• Albireo (Cyg A) and Cyg B double. My friend JamesB had told me this was a nice colourful double to view, Cyg A is spectral type KIII+ and Cyg B is B8V. A is the primary member of the system, a golden yellow or “topaz” star shining at 3rd magnitude, while B is known as the companion, a fainter 5th-magnitude star with a beautiful bluish color. Ref link.
• Ring Nebula in Lyra. I’ve wanted to view this nebula for quite a long while, and tonight I found it, purely by star-hopping. It is quite easily found, and I viewed it with a variety of eyepieces and Barlow to see what I could make out, the actual ring was fairly clear, but I was unable to resolve the central star. Ring Nebula on Wikipedia.
• M56 Cluster. This again I found by star-hopping, and lies about half way between Albireo and Sulufat in Lyra, near the Ring Nebula. A nice but quite faint cluster.
• Uranus. Next I noticed in Stellarium that I might be able to see Uranus between the head of Pisces and Aquarius. Again this would be a first for me so thought I would try to locate it according to the position shown on the laptop. I figured it might possibly be visible through my 20×80 binos, so got those out and set them up on the tripod with the ST90 counterbalance. After some hunting around familiarising myself with the stars in the area (in particular a pretty rocket/arrow shape formed by HP114914A and 3 surrounding stars, with 3 small stars in a line), and comparing with the view in Stellarium, I was surprised at how visible it was at around mag 6. I was just able to see if with the naked eye, also easily with the binos, and I could clearly make out the disc of Uranus with the XT10, but didn’t think to pay attention at the time whether I could make out any of its moons (didn’t think about that until back at my computer indoors looking at Stellarium again). The moons reminded me of the song Astronomy Domine by Pink Floyd - “Oberon, Miranda and Titania”. However, Uranus was fairly low in the sky, and also there was some light wispy cloud cover over that part of the sky which was not helping. Still, it was a nice catch!
• Pleiades. Well I just love these stars, and always enjoy looking at them. I love their clear bright view. For amusement I tried counting how many I could see in this cluster with the XT10, but gave up at around 60 stars! I think I could even make out some of the faint nebulosity around the stars.
• Aldebaran in Taurus. Next I worked my way down to the Taurean stars and marvelled at the orange/red of Aldebaran and pondered for a while the immense size of this star.
• NGC1647 (Open Cluster). Just about 3 degrees to the north of Aldebaran is this nice open cluster.
• Crab Nebula. While in this vicinity I thought I would try to find the Crab Nebula. This is a nebula I have tried to find before, but conditions weren’t good enough the last time.  This time I discovered it was just barely visible with the 20×80’s (with averted viewing) and quite pronounced through the scope.

This was approx 3.5 hours stargazing from 9.30pm to 1.00am. I would have liked to continue, but by now the night air was getting pretty chilly, and dew was starting to become a problem. Also my dog Ben was getting a bit bored and wanted to go in!

I wonder how folk are getting on at the Kelling Heath Star Party this week and weekend, and whether the weather has been kind for them?

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Listed in Observing, XT10

Yesterday evening I got home from work and took the dog out for his walk. It was a lovely clear night and the stars were nice and bright, so I was feeling quite excited about the prospect of some decent star gazing (wifey is away tonight). Got back home and immediately took my XT10i telescope outside to start cooling down. Next I went in, did the dogs supper and prepared myself some tea, and ate it quickly so I could get back out for some observing. I was about 20 minutes in all. Went back outside and couldn’t believe it. Once again those blasted clouds had moved in to spoil the fun. Damn!

Oh well. Plan B. At the weekend I had ordered some Protostar black velvet flocking material to line the inside of the scope to reduce reflections from ambient light bouncing off the insides, and so increasing the contrast of the view. And it had just been delivered that morning.

So I set about carefully dismantling the scope to remove the primary and secondary mirrors, and the finder scopes, so I could install strips of the flocking material easily. The job took about 2.5 hours, by which time it was too late to put everything back together.

Tonight I decided to finish the job by cleaning both primary and secondary mirrors, and adding a touch of black matt paint to various bolts inside that were shiny, and apply some to the edges and back face of the secondary mirror. I carefully followed instructions for the best method to clean the mirrors, so as not to scratch them or remove their aluminised protective coating (I’ve had the scope almost a year now and a fair amount of dust has gathered on the primary).

Finally I re-assembled everything and re-collimated the mirrors as precisely as I could. When all was done I took the scope outside to see what improvement the flocking had given. It’s been a fairly clear night, with the occasional cloud passing over. The Pleiades were visible so I lined up on them and checked it out.

Now my rear garden has a white light (mercury) street lamp to the North side, and I have always noticed when pointing the scope to the North or East, that the light entering the end of the scope tube (unless I get our large patio table umbrella out to shield the light) always gives a lightening or greyness to the view.  But with the new flocking there is a considerable difference, with a very much darker view, which does indeed give better contrast. Certainly looking down into the tube from the top it looks very dark inside.

Nice one. As usual I have taken some photos of the flocking work, and will create a new page in my main web site describing how it was done, and where I got the material from. Watch this Space.

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Listed in Collimation, XT10, XT10 Assembly

Tonight at first sight looked promising with stars out, but not very good transparency.

I started by setting up my 20×80 binos to try them out with the ScopeTeknix Zodiac ST90 counterbalance binocular mounting which I bought at the same time as the binos, but until now have not had the opportunity to use them. The counterbalance mount is very sturdy and heavy (needs to be to handle the 20×80 binos which themselves are quite hefty beasts). While they work quite well with my tripod, really the tripod itself which previously I had bought for use with my SLR camera, is not sturdy enough, and could ideally do with being a bit taller. Care is required when adjusting the tripod height, because the weight of the combined bino+tripod can overwhelm the height crank, and if you’re not careful the crank handle suddenly starts to spin, and bump, the binos and counterbalance drop down.

Of course quite typically within the time it took me to setup the binos for viewing, clouds moved in!

But since it was quite a pleasant dry evening, I thought I would push on and get the XT10 out too, in the hope that the clouds would clear later in the evening. One thing I wanted to do was have another go at configuring the Intelliscope Computer Object Locator to interface via RS232 thru USB port and an ASCOM driver, to work with Carte du Ciel on my laptop. With no stars visible I had to make do with guesswork alignment, i.e. point the scope at roughly where I knew a couple of alignment stars were. I knew this would be totally inaccurate, but all I wanted to do was understand what settings were required to make the software read from the Intelliscope, and be able to track movement of the OTA as I moved it, updating on screen to show where it was pointing. This task worked, and later on the clouds did indeed clear, and I was able to make a more accurate alignment, and check the software tracked what I was pointing at accurately too. The objective for tonight was more to re-familiarise myself with the Intelliscope plus tracking software, while some checking for certain problems I had noticed with losing the tracking connection if other Intelliscope buttons were pressed, would have to wait for another brighter stars night.

Next I wanted to try out my new Baader UHC-S Filter to see what effect this would have on observing things. It is designed to cut out light pollution from mercury and sodium based street lamps, so that the view has more contrast. First I sighted up with the binos to see if M31 The Andromeda Galaxy was visible, and eventually found it in the binos. I then manually located Andromeda in the XT10, and tried out the filter with a couple of different 1.25inch eyepieces which the filter would screw into. The filter didn’t seem to have much effect, but this could be for a couple of different reasons; a) its the first time I’ve used it so I don’t know exactly what to expect, b) this galaxy may not be quite the right thing to use the filter for viewing, c) the view may not have been bright enough, due to the poor transparency (while I was trying the filter out, more clouds came in and halted my comparisons). So I think more experimenting is required to see how effective the filter will be on a clearer brighter night.

Tonight has also been the first time I’ve used the scope properly since adding the “carpet brakes” to provide some stiction to the Lazy Susan bearing modification I recently did to the dobsonian base. The scope moves very freely now, but the carpet brakes appear to work well, providing about the right amount of stiction.

Finishing off before a swaith of clouds rolled in to put an end to my nights observations, I observed the Moon, very low down and red hued, and with the seeing playing its usual tricks to try and mar the view, and also explored around Cassiopeia for anything of interest, and came across M103 and NGC457, both open clusters.

So it was a bit of a mixed bag of things I did tonight, but mostly just for want of getting out there and trying something out despite the usual poor views and bad weather. I really hope that as September draws to a close, and the nights get longer and darker, that the skies will clear up and start to reveal their gems again.

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