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Posts Made By: Charles Stevenson

January 5, 2015 10:20 AM Forum: Beginning Astronomy?

Taking the plunge

Posted By Charles Stevenson

Santa brought our family a Celestron PowerSeeker 70AZ for Christmas (with the red dot LED finderscope). We have a large east-facing window in our house and setup the 'scope indoors after freezing outside a few nights. I got the bug looking at Jupiter a few days in a row--and also the moon which was almost full. With Jupiter I could see two moons as small white dots and Jupiter also looked like a larger white dot with even the most powerful optics that came bundled with the $50 telescope. It sparked an interest that had laid dormant and I had to see more detail.

We purchased a well treated Celestron C8-A XLT on a CG5 ASGT with the GPS attachment. It actually hasn't arrived yet. I've tried to slow down a bit on ordering odds and ends before it arrives and I see what's what. I have ordered various filters (including OIII) and the f/6.3 reducer. I have an interest in astrophotography and have been reading posts on here as well as information on other sites. I discovered there's an astronomical society within a few miles from my house and have filled out the application.

I have all sorts of questions and don't really know what to ask first. So, I'm basically just introducing myself... I've appreciated Uncle Rod's posts and blog and affection for the C8 + CG5 ASGT. When I bought the C8 and mount I actually hadn't done any research. I'm really grateful that luck was on my side and I actually got something decent. =)

When the new scope arrives, should I take it for a spin or is there a checklist of things to inspect/clean/lube first? It's a used setup. I'm not shy about disassembling things and already read one of the howtos.

January 8, 2015 04:01 PM Forum: Pictures of Me and My Telescope and........

Day 1

Posted By Charles Stevenson

I finally got everything together. Thankfully, the previous owner meticulously labeled and packaged everything and included the manuals. This may sound absolutely stupid but I wanted to make sure when I'm counterbalancing the scope with the weights that the bar should be parallel to the ground?

After goofing around I plan to put the guide scope back in its box until I am able to venture into imaging. I am able to see some things by opening my office window and the guide scope doesn't allow the GoTo to turn everywhere it wants without risking colliding with my desk etc.

January 10, 2015 01:11 PM Forum: Beginning Astronomy?

Which diagonal should I use?

Posted By Charles Stevenson

Dear ones, I received two diagonals with my C8: a 1.25" and a 2". I have 1.25" EPs. The thought occurred that perhaps the 2" with 1.25" EP adapter might be better quality than the 1.25" diagonal.

Celestron Star Diagonal 1 1/4" #94115-A
vs
Celestron 2" XLT Schmidt-Cassegrain Diagonal #93527

I don't know much about the 1 1/4" ... will look up the model #. The 2" came in a fancy box inside of which is a luxurious looking hard case which made me think perhaps this diagonal might perform better....

Edit: I also noticed that the 2" has a threaded ring which looks like it would hold on more securely than the smooth part of the 1 1/4"

January 11, 2015 11:10 AM Forum: Beginning Astronomy?

Surviving the cold

Posted By Charles Stevenson

It's been fairly chilly here lately with one night somewhere around -10F. Last night it was in the low teens. My Celestron mount, gps, and hand controller all stop functioning properly once they get that cold. When I bought my scope it came with an 8" dew heater strap but no controller. I rigged a controller out of an old 12v electric car heater that had a fan. I connected a piece from an old 24v audio distribution amp to match the dew heater plug. When the switch is toggled to Fan only the dew heater receives current. When I toggle to Heat both the dew heater and the heating element from the original heater kick on. The heating element gets way too hot so probably need some sort of knob to control how much juice it's getting. I had initially thought the troubles were the hand controller and GPS so last night I had the heater band wrapped around the hand controller long ways so my hand could slide in and run the controls. That solved the problem with the hand controller crapping out. The heating element I zip tied to the GPS and would turn it on and off in spurts. But then my RA and DEC motor controllers (16 & 17) stopped sending a signal. Is there some sort of component that's easily susceptible to cold like a capacitor or such? Do I need to have heat for each of the motor controllers too?

January 12, 2015 06:18 AM Forum: CCD Imaging and Processing/Deep Sky

Hyperstar Alternative?

Posted By Charles Stevenson

Hello all, I've been Googling around and haven't had much luck. Is there an affordable alternative to the HyperStar 3 lens for an 8" Celestron? Is the lens absolutely necessary? Can something be rigged up or machined or 3D printed... Gorilla tape? ;-)

January 20, 2015 09:18 AM Forum: Beginning Astronomy?

North Celestial Pole

Posted By Charles Stevenson

Hi all, I'm starting to get the hang of setting up the C8 and ASGT mount and am not having tremendous accuracy with the Goto. I've finally figured out where Polaris is from my back yard. I'm a slow learner (lol wink ). I did align the optical axis on my polar axis finder scope and so at least that's working out...

Not having any sort of permanent place to setup the tripod I used spray paint to mark where the tripod legs have been that's pretty close to aiming north. I removed the polar alignment scope and looked through the opening with the naked eye and moved the tripod until I could see Polaris. Then I put the polar scope back into the mount and adjusted the various screws until Polaris was in side the circle on the perimeter of the circle surrounding the NCP.

I feel like Cassiopeia has been the easiest to see. In fact I'm not sure I have been able to discern the big dipper. The pattern etched in the polar scope is black and hard to see, if at all, against the sky. I've found that shining my red light into the hole a bit from the top illuminates the pattern while allowing me to see Polaris. Cassiopeia doesn't seem to match the location in the sky in relation to where I've positioned Polaris. I'm not sure if I'm doing something wrong... (see attached image).

Anyways I figured it was closer than I've ever gotten before to being polar aligned. I adjusted the azimuth screws so that it was horizontally in the right place. I then adjusted the altitude screw so that it was vertically in the right place. I followed the manual "make final adjustments in altitude by moving the mount against gravity (i.e. using the rear latitude adjustment screw to raise the mount)" and removed the front latitude screw. Then I tightened the mount to the tripod and confirmed Polaris was still in the small circle.

Once Polaris is in the small circle do I then lower the altitude back to my latitude? It seems like the polar axis was much higher... Thanks for your help!

January 21, 2015 11:50 PM Forum: CCD Imaging and Processing/Solar System

DIY Thermoelectric (Peltier) Cooling Modules

Posted By Charles Stevenson

Hi all, wondering if anyone has added 12V Peltier chip(s) with heatsink plus fan and/or water cooling to their CCD camera? I'm reading all of the specs for the available chips and am not sure which chip is best. I read someone achieved -28C with a TEC-12710. I believe the TEC1-12730T125 with higher wattage can cool more?

For CCD the colder the chip the less noise right? :S I'm asking because I've found a camera with Sony ICX285AL for primarily industrial application that doesn't have built-in cooling but is priced about $1,100 cheaper than the Atik 314L+ Monochrome and $1,700 less than the Starlight Xpress Trius SX-9 (albeit without an argon sealed chamber) and so on and so forth for every other camera I can find. Somehow attaching the word astronomy or astrophotography to an item adds a lot of cost.

The TEC1 chips cost about $5. I could use the cooling fan and copper heatsink from a dead laptop or perhaps an aluminum heatsink and fan. A kit with watercooled block and all the other parts (not including water pump) is about $50.

January 24, 2015 08:36 AM Forum: Comets

Gearing up for 2004 BL86

Posted By Charles Stevenson

I read in the News section that "an asteroid designated 2004 BL86 will safely pass about three times the distance of Earth to the Moon on January 26, 2015." I'm hoping for good conditions to look for it. I imported the data into Stellarium and hopefully it's accurate. Anyone else gearing up for a look?

January 25, 2015 09:49 PM Forum: CCD Imaging and Processing/Solar System

Back Focus Distance Tips

Posted By Charles Stevenson

Me again... I'm reading up on imaging and all of the terminology and gear. I've sort of capitulated on my quest for a HyperStar alternative and am now wondering about back focus. My camera currently has a C-mount w/flange focal distance of 17.526mm (I think this is the universal standard for C-mount?). Starizona says HyperStar backfocus from mounting thread to focal plane is 39.8mm. Assuming I am able to find a used Hyperstar for my C8 and put the camera where the seconary mirror usually goes... what does the setup look like? Hyperstar (w/possible filter(s)) -> spacer -> C-mount? And then I focus by moving the primary mirror?

Confused as always... wink [image from Baader website attached]

January 27, 2015 09:58 PM Forum: Telescope Making

Tubes for Reflecting Telescopes

Posted By Charles Stevenson

Nice article here: http://www.alpo-astronomy.org/jbeish/Tel_Tube.pdf I found the section on tube color very thought provoking.