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Topics - buddderpdrivla

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I am a high school Physics/Engineering teacher at a small PBL based high school in Evansville, IN. (http://www.evansvill.../real-world-now) In my teaching experience of 31 years, I have introduced students to Astronomy with borrowed telescopes or telescopes that I have picked up at yard sales. ( http://www.cloudynig...-i-ever-spent/) That first year I showed students sunspots, and the rings of Saturn; one of those original students became a science teacher and is now my principal!

I got away from Astronomy for several years but got the bug again last summer after finding that RV-6 last summer. I have started an Astronomy club at our high school and have recently acquired a Celestron 8SE from a donor. The kids and I are very excited, but the weather has been rotten for some time. However, with the solar eclipse coming in August of 2017 we have a unique opportunity as we are only 70 miles from Hopkinsville or Princeton, KY which will have a 2:40 second duration of the eclipse. We plan to take all of our students to experience this once in a lifetime event, but I want to them to see this in a number of different ways. This is where I need your help, and the members of Cloudy Nights have been more than helpful on several occasions in the past.

I want to purchase a dedicated solar scope (Lunt or Coronado?) , tripod, a video camera, and a solar filter for the 8SE, along with several Sunspotter Solar Scopes. What equipment would you recommend for this? Is there anything that I should be considering?

I have a number of goals with the Astronomy club’s future:
1) To get my students comfortable enough with the telescopes so they can do outreach programs at other schools and with adults.
2) To build an observatory so the school can have access to the telescope from their computer at home. Our school is in the Career and Tech Center and the students have the ability to design and build the observatory under one roof. (http://www.edlinesit..._Programs/SICTC)

Occasionally I see posts on this forum of people posting about something they may or may not have seen while out observing.

Our heightened sense of awareness, fatigue from being up late, and dimly lit surroundings can indeed sometimes play tricks on us. That does not however discount the fact that people may be seeing something unexplained or mysterious while out alone in the wilderness.

This could be but is not limited to paranormal activity or unexplained animal behavior (bigfoot, chupacabra, etc) or even mysterious human behavior. However let's avoid UFOs because that's another topic.

Any opinions or stories are welcome.

I've been looking for a good zoom eyepiece on a budget for some time and this little gem popped up. Yep, thats a real Nikon 7-21mm zoom eyepiece for the same cost, or less, of a cheap no name zoom. Plus it'sfrom a brick and mortarauthorized Nikon dealer. While it's not as desirable as the MCII, it's a quality zoom with a 40-60 FOV that originally sold for £130 back in 2006(search for "15-45X" in the linked official Nikon price list from 2006). I personally tested it and found it far better than any of the budget Plossls (Gosky, Sbvony, etc) I have laying around and should give the Meade and Celestron zooms a run for their money.

I will say you will need to find/make a 1.25" adapter but there's a couple threads on how to do that on CN and elsewhere. Even with making an adapter, you still end up with a very nice zoom for less than used Celestron or Meade zoom.
It's cousin as reviewed by Cloudy Nightsand detailed images of the EP that's being sold.

Clear skies and good gear on a pocket change budget.Disclaimer
I'm in no way associated with the seller or receiving any thing for posting this. While I was thinking about picking up a second EP for later when I could afford it, I figured the community would be better served by letting everybody know about it.

Hey everyone,

So a couple days ago, I found my first ever DSO: M13. I haven't had my equipment for too long and haven't put much effort in DSOs so far, mainly due to the lack of a good finderscope/telrad (which I'm anxiously awaiting by the end of this week!), but now I'm hooked and will be looking for more!

90% of my viewing is from the backyard in a red zone, so not the best for DSOs, but I'll be extremely motivated to do the 45min drive to the nearest yellow/green zone more often.

Anyways, it was a pretty nice and rewarding feeling finding the faint M13 for the first time, and practicing averted vision, which brought up a bunch of little stars around the faint smudge of the cluster!

So that was using my Vixen 70mm refreactor and a 25mm Plossl.

I immediately thought, wow, if I can see this object with the 70mm, it will be much brighter with the 130mm reflector, so I quickly switched OTAs on the mount and finally spot M13 with the reflector....... hmm, pretty much the same faint smudge as with the 70mm...

So my question is, is it safe to assume that in a sky polluted area, larger apperture doesn't mean brighter objects that are pretty faint in the first place?
I guess the aperture difference will make a big difference in dark skies, but in a bad sky, will not help much if at all?

For what its worth, the refractor is a 70mm f/13 and the reflector a 130mm f/7, same eyepiece used on both.I'm leaving this Saturday morning for a 6 days/nights fishing trip in a "dark grey area" and the weather forecasts so far are looking very good.... I can't wait for doing some DSO observation in a real pitch black sky!!!!

Mounts Questions & Expirience / Avalon M Uno RA Drift
« on: December 30, 2017, 10:14:04 PM »
I've always noticed drift in RA during drift alignment. It never bothered me because I had no intention to image unguided, and it never affected my guiding which has always been superb. But the issue was raised in another thread and so I decided to examine it more specifically. I am perplexed by my observations and was hoping that a mount guru coulld help. i am presently imaging with a 9.25 [email protected]/10, QSI640 wsg/Lodestar with an image scale of 0.65"/pixel. My mount has always drifted in the same direction when drift aligning and I assumed this was related to slight siderial clock/tracking error. StarGo has a fine RA adjustment slider, and it has been suggested that I use this. I don't know what the units are but found that an adjustment of -50 to -70 has reduced the drift, at least at the meridian and dec 0. So last night I too k several screen shots to help explain my observations. Seeing was below average last night, so my guide total RMS error was in the 0.6"-0.8" range

This is at the start:

This after 5 minutes of drift at at the meridian and close to Dec 0. The polar alignment seems good (little dec drift). Tracking adjustment is at 0
This is after 5 minutes of drift with tracking adjustment set to -100
This is after 5 minutes of drift with tracking adjustment at -60, so I set it at -65 and thought I was good to go.
More to follow

Reflectors Telescopes Forum / Steel 'invar' in mirror cell's
« on: December 29, 2017, 06:12:13 AM »
The idea to use the same steel ZTE as the glass itself in the mirror cell can't be a bad idea.
If one has example ZTE free glass and aluminium triangles at ppm/c or ZTE 23, is not to great idea.
If it sticks against mirror and 2 materials it will try twist the figure.
I will have a Quartz mirror and that material has ppm/C at around 0.5, and I read on steel ( Invar ) and that has ppm/C at 0.62, so a pretty good match.
I can machine, but I has never come across that material before.
Has anyone here used it or has knowledge ?

Samples of Invar
Like other nickel/iron compositions, Invar is a solid solution; that is, it is a single-phase alloy, consisting of around 36% nickel and 64% iron.
Common grades of Invar have a coefficient of thermal expansion (denoted α, and measured between 20 °C and 100 °C) of about 1.2 × 10−6 K−1 (1.2 ppm/°C), while ordinary steels have values of around 11–15 ppm. Extra-pure grades (<0.1% Co) can readily produce values as low as 0.62–0.65 ppm/°C. Some formulations display negative thermal expansion (NTE) characteristics. Though it displays high dimensional stability over a range of temperatures, it does have a propensity to creep.


I'm brand new to amateur astronomy, having just acquired my first scope - an 8", f6 dob (XT8 Plus, specifically). I've taken it out every clear night and I'm already sure that this will be a hobby I will be investing some time (and money) in. I've spent some time reading through these forums, and have read through two highly recommended books ("Nightwatch" & "Turn Left at Orion"), but there are some things I could use some further advice on:

1. Light pollution: I live in an urban environment (Alameda, CA - basically downtown Oakland) and the light pollution is awful. I have 3 young kids, include a 1 month old, so my ability to get away from home to seek out dark skies will be limited for the foreseeable future. I understand that many deep sky objects will remain out of reach from my location, but I still want to seek out all the open clusters and multi star systems and any other bright objects that I can from my own backyard. Considering my gear, and that I have no GoTo technology, I'm reliant on star hopping to find my targets, which is quite difficult with my severe light pollution.I had considered getting an extreme wide angle eyepiece at low power with which to break through the pollution to navigate the skies for star hopping purposes.Is this a feasible solution? Perhaps coupled with a broadband filter?Any other advice on star hopping in severe light pollution without GoTo technology? Also, can you please recommend a resource for light pollution maps?

2. Filters:I'm considering purchasing two different filters, a broadband filter to dampen light pollution (noted above - although I question how helpful it will be), and a narrowband filter for nebula viewing from home and on rare occasions when I can get away from the city. Regarding the narrowband, I've read great reviews on the DGM NPB, so that's currently at the top of my list. With that in mind, I'd rather not pay the full $150, so I'm mulling the idea of getting the "cosmetic 2nd" discounted piece from Amazon (, but I'm concerned about the fact that the flaws include "cosmetic flaws, such as pinholes, sleeks, or light scratches". Are these flaws significant when it comes to filters?Or should I trust DGM when they say "flaws which have zero impact on optical performance. Spectral characteristics are the same high quality as our first quality filters and side by side performance is indistinguishable."

3. Eyepieces:There's so much information out there on eyepieces, it's difficult to settle on which eyepieces to target next. The XT8 Plus comes with an Orion 10mm plossl and 28mm "Deep View". The plossl seems well enough for now, but I don't feel that the Deep View provides enough FOV for a lower power eyepiece, so I think a low power, wide angle eyepiece will be my next purchase.With that in mind, any recommendations on the ideal "True FOV" to shoot for low power viewing? I know 2"+ will be necessary to take in all of thePleiades and Andromeda (for example), but is 2" considered overkill, or is this a good TFOV to shoot for? Any other eyepiece advice you can provide regarding building a strong initial eyepiece set would be helpful as well (considering mid to high-tier options).

Thanks a lot!

Mounts Questions & Expirience / Celestron CGX
« on: December 27, 2017, 07:50:32 PM »
I am starting a new thread to discuss the actual performance and experiences with the new CGX mount from Celestron. I have noticed many sales and It seems to be showing up in stock at many retailers now and hopefully users can start reporting their experiences with it.

Some questions I have...

Are the handles helpful?
How is the tripod? The tripod is wider and so far the reports seem to be pretty good.
How is the new design of the base with regards to setting it on the tripod and making Alt/Az adjustments when polar aligning?
Any issues with the USB port(s)?
Does anyone have the (Planewave) software yet that allows one to use the mount directly without the hand controller?
How good is the imaging with a 10" or larger OTA? Or with a smaller refractor?

The mount appears to be a replacement for the CGEM/DX and probably a good one, given the redesign of the worm drive, which has always been a weak link with the CGEM series. It has a stated instrument capacity of 55 lbs and many are curious if it lives up to that. At the very least, that should cover an 11" and its equipment pretty well, which would be an improvement over the CGEM/DX. The mount has a very good set of features supporting remote operation. Especially the home and limit switches. Have any users connected it to the standard control programs like MaximDL and SGP yet? I am also interested in the capabilities of the Planewave software that will eventually be released by Celestron for it. It is supposed to support multi-point modeling, although plate solving seems to be the way now, which I suspect it will also support since Planewave is also the author of Platesolve2 which is popular.

There have been a couple of threads started when the CGX was first introduced, and naturally, since it was so new, they are filled with conjecture and misinformation. Since the mount is now solidly in the supply chain and users are buying and using it, I would hope that this thread sticks to facts and real experiences regarding the CGX. Personally, I have a CGEM and a CGE Pro, and if I were to purchase a CGX it would replace my CGEM as a portable mount.

General Astronomy & Observing / Am I seeing red in M42?
« on: December 24, 2017, 04:15:58 PM »
Last week was the very first time I was able to stage my 16" Dob in The Orion Nebula since I received it, and I was floored by the detail, but over that, I am pretty sure I noticed a very subtle red hue along "the bar".  I looked  last night, and it seems like it is not an illusion, it is more evident at low forces, using 23mm (~80x) and 15mm EPs (~120x); with a 7mm(~260x), the red is almost unnoticeable (but the depth in the nebula was astonishing).  This is actually the first time I've noticed red in M42, and I've looked at it throughout the 60" scope at Mt. Wilson Observatory (though at approximately 240x); it is more surprising that I am seeing within ten miles of downtown Los Angeles.  I am still a little skeptical that I am viewing the colour for sure, has anyone else noticed the exact same colour on "the bar"?

Beginners Forum / Equatorial mount Polar alignment without Polaris?
« on: December 24, 2017, 12:19:28 AM »

I wanted to inquire if it's possible to perform polar alignment for my EQ bracket without visiting polaris?  as Polaris is blocked behind a wall, so is there a way to work around that?

Thank you

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