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Posts Made By: Roger Cole

August 6, 2002 07:38 PM Forum: Deep Sky Observing

Bino report part I

Posted By Roger Cole

Bino Observation Report - New Orions strain the milk pitcher

Ok, I'm calling Sagitarrius the "milk pitcher" instead of the "teapot" because of the LP I have to the south at my parents' house where this took place, and tried to style the title after Ron's great Light Cup obs reports. Imitation and flattery and all that, Ron. ;-)

************************************************

Aug 05 2002

Date: August 5, 2002 (UTC, Aug 4-5 EDT)
Time: 0225 – 0400 UTC
Seeing: 7/10
Transparency 5.0 North, 5.5 ZLM, 4.0 South

Instrument Used: Orion 10x50 Ultraview binoculars, mounted on Bogen 3021 tripod with tripod adapter.

Objects Observed:

M4
M6
M7
M8
M13
M20
M21
M22
M23

Set up in side yard at parents house and got started about 1025 local (EDT) time. Eta Ursa Minoris (mag 4.9) was barely visible with direct vision before I was fully dark adapted, so limiting magnitude toward the north was about 5. Overhead, I estimate the ZLM at least 5.5. However, to the south toward Sagittarius the neighbor’s lights make it much more difficult, though the direct glare is blocked by my parents’ barn. Mu Sagittarii at magnitude 3.81 takes a careful look, though it is there. Limiting magnitude toward the south is closer to 4. Seeing is fairly good, at least as far as I’m able to tell with 10x binoculars. The views are steady.

First target is M7. In spite of how prominent it can be to the unaided eye it is NOT visible unaided, or at least I can’t see it and I do find it readily in the binoculars. In spite of the light background it is still very pretty. My notes comment, “Looks like an X-Wing!” Interesting that I see a winged object from the mythology of my youth in this and not in M6, which is up next. I make a half hearted attempt to count stars, but the background in this area is just too rich.

Moving up to M6, my notes say, “reminds me of a miniature [constellation of] Orion” and I have a very small crude sketch that shows it this way.

Later and indoors, I look at both with Starry Night Pro. After playing with the limiting magnitude and setting it at 10, I manage to recreate the “X-Wing look” look of M7. M6 takes more work and dropping the limiting magnitude to 9, then it looks “sort of almost maybe a little bit like” my sketch. The X-Wing is obvious but I have to convince myself I see the butterfly shape in M6. I’m not at all sure of it even so. It doesn’t look much like Orion either, indoors.

document.

August 6, 2002 07:41 PM Forum: Deep Sky Observing

Binos - Luna, Saturn, M45

Posted By Roger Cole

Aug 05 2002

Date: August 5, 2002
Time: 0840 UTC
Seeing: 7/10
Transparency mag 3.5, LP

Instrument Used: Orion 10x50 Ultraview binoculars, mounted on Bogen 3021 tripod with tripod adapter.

Objects Observed:

Moon
Saturn
M45


I had been on the ‘net a long while and was completely unable to sleep before 0430 local time. This frequently happens to me since I work shift work. Not having to be back at work for a few days I didn’t worry about it. But I noticed the waning crescent moon from my deck and decided to take a look with my new binoculars.

I didn’t look long enough nor consult references to find any specific features on what little of the moon was illuminated, but this being my first view of the moon with these I was very pleased. I was really impressed with how much larger the image is just comparing 10x to 7x. The limb was very sharp with a hint of false color that was far FAR less than in my little 7x35 Bushnells. For whatever reason, those little binos show a very prominent blue/violet fringe on the lunar limb. My new Orions showed a much smaller yellow fringe, or perhaps a hint of blue on the inside of the bright/dark dividing line and yellow on the other, the yellow being against the black of the sky. Earthshine was very prominent and almost breathtakingly beautiful.

I then turned toward Saturn a few degrees away. Now here was a surprise. I have always heard that about 30x is needed to see Saturn’s rings. I’d certainly never seen a hint of them in binoculars before. I didn’t see clear rings now, either, but like Galileo I could tell “something wasn’t right.” The planet was very clearly elongated and by looking very closely in moments of good seeing I could almost convince myself that I saw the rings against the sky, though not, of course, the rings against the planet. When I came inside I checked the position angle with SNP and found I was correct about the orientation of the rings!

I then noticed M45, always a favorite object of mine, higher up and had a look. In spite of the LP, it was gorgeous! Of course, the Pleiades are gorgeous with most any optical aid. I counted 40 stars visible, though I wasn’t sure exactly where the cluster ended so wasn’t entirely sure where to stop counting. No hint of nebulosity, though.

I find debates about the Pleiades nebulosity a bit curious and puzzling. Consolmagno and Davis indicate in Turn Left at Orion that a 6” or larger scope is needed to see it, while O’Meara in Deep Sky Companions, The Messier Objects says that he can see it unaided and the late Walter Scott Houston scoffed at those who claimed it wasn’t visible unaided! I have a suspicion that this depends very much on sky conditions. TLAO is written toward the urban and suburban beginner, while O’Meara observes from some of the best sites available anywhere (plus has very keen eyes.) Maybe any LP just washes out the background too much?I suspect.

August 24, 2002 09:37 PM Forum: Equipment Talk

Nexstar 8 GPS vs LX90/UHTC

Posted By Roger Cole

Ok, ok, I know the LX90 UHTC is a lighter weight scope, has less clearance at the base, no PEC etc. It is also considerably cheaper. With the current discounts on both, the delivered price difference comes to $284, depending on how much the dealer charges for shipping the NS8. That figure is based on one published shipping charge for it and Meade's rather excessive "one price to overcharge everyone" for their shipping and handling. Then, there's the eyepiece deal.

At this stage I don't plan to start imaging, at least not for a while, but having been into photography quite heavily for years and still having an equipped darkroom, so it may well loom - or CCD for that matter. Either will be a while, though.

If it weren't for the eyepiece deal I'd probably go for the NS8 GPS due mainly to the heavier fork, gears, motors, and increased base clearance. (I feel pretty sure I will go to 2" eyepieces before too long.) But the fact I have no eyepieces now having sold all my old ones along with my last scope means that eyepiece deal is, well as I put it somewhere else, "a mess of eyepieces for a hundred bucks." I consider the 40 of limited usefulness due to the field stop of the 1.25" barrel, and the eye relief awfully short on the shortest ones, but there's still some decent mid range eyepieces there and the ones I don't want can be sold. Eventually they'd probably be replaced with better ones, but this gets a case of usable eyepieces to start at a good price.

Add the hundred bucks and the LX90 WITH eyepieces is still $174 less than the NX8. But then there's that heavier mount - I'm sure I'll want to piggy back a wide field of some sort later, I've been told the LX90 handles an ST80 ok but maybe not anything bigger - and the base clearance, and the NS 8 has the Fastar option. No downloads now whereas Meade does. Of course the NS8 GPS has the GPS, which I considered a complete frill but some knowledgeable people have told me it does speed set up.

Any thoughts? I believe there was someone here who had an LX90 and was selling it for the NS8 for more base clearance?

Apologies to those who endured the similar thread on s.a.a.!

Roger

December 17, 2002 02:37 PM Forum: Equipment Talk

Eyepiece Simulator Link

Posted By Roger Cole

I saw this link on sci.astro.amateur and thought it was an excellent demonstration of the differences between eyepieces of various AFOVs as well as true fields and such. It really shows the advantage of 2" and wide afov eyepieces:

http://www.stic.net/mattwier/

January 30, 2004 10:26 AM Forum: Deep Sky Observing

Re: Finding Andromeda

Posted By Roger Cole

You're looking about 75 degrees away from where you need to look.

I set Starry Night Pro for 8 PM tonight in Phoenix and took this screen shot to help you. Look in the west for the big square of stars, the "square of Pegasus" as shown in the map. From Alpheratz, the star in the North West corner, there will be two lines of stars trailing "up" ths sky. This is the constellation Andromeda. Follow the more northerly of the two (the one on the right) up to the third star from the corner of the square and look just to the right.

Once you know where to look it is easy to see, but don't expect it to look like much to the naked eye. Just a fuzzy oval blob. It should be spectacular in 22x100 binos, though. It always blows me away in my 10x50s.

February 26, 2006 05:12 AM Forum: Refractors

Re: na120s from vixen

Posted By Roger Cole

I'm not sure but I think the NA120 is a Petzval with the extra element aimed at flattening the field. I believe (maybe Roland or one of the gurus will chime in) that a Petzval design can be made to show less CA than a regular achromat, but does't automatically. So the main goal of the scope may have been to get a flatter field for wide view imaging, where the ca will make much less difference, rather than to reduce the ca below that of a normal achromat.

March 9, 2006 05:58 PM Forum: Beginning Astronomy?

Re: one eyepiece

Posted By Roger Cole

don treat said:

im trying to avoid spending money needlessly on eyepieces. so here's my question. if you could only have one eyepiece for an 8" sct what would it be? and why?

I'd sell it and buy a dob and use the extra money for eyepieces.

Note that I am NOT against SCTs, in fact I've often considered buying one. I just think paying more for a scope (compared to a dob, or even an achromatic refractor) then not being able to afford or being unwilling to buy eyepieces would be silly. It's sort of like buying a very nice socket wrench then asking which ONE socket would be most useful.

But if you had to, an SCT would be a good scope to face that choice with because you can get an f/6.3 R/C in addition to a Barlow and get three magnifications out of one eyepiece! wink

March 12, 2006 01:22 AM Forum: Beginning Astronomy?

Re: The Chicken Nebula. Or, Good Stuff for New Ast

Posted By Roger Cole

Thanks for the link; I've bookmarked it to watch later when I have time.

But... I am a vegetarian (well, "lacto/ovo/pisco" - I eat fish) and I'll bet I still will think it's funny. wink

May 4, 2002 12:06 PM Forum: Equipment Talk

question w/ CG5 dual axis motors

Posted By Roger Cole

There is probably nothing wrong with it. You may be confusing drive speed with slew speed. When manufacturers reference "motor drive" speeds, they usually mean, for example, 8x sidereal rate. This is nowhere NEAR fast enough for effective slewing. Slew rates depend on the manufacturer too, and are usually, as far as I've seen, simply referenced to their slowest one. So the slowest slew rate (which will be much faster than an 8x sidereal "correction" rate) is 1x and the fastest, if it is eight times as fast as that, will be 8x slew rate. One manufacturer's 8x slew won't necessarily have anything to do with that of another, or even another mount/motor from the same manufacturer.

"Corrector" rates are meant for correcting tracking for photography, or for very fine adjustment of the image position visually, not for slewing across the sky. I think what you have is probably not intended for slewing, but for fine adjustments of tracking.

June 9, 2002 01:40 AM Forum: Equipment Talk

EQ Platforms

Posted By Roger Cole

I don't know how good they are, but these are in your price range:

http://www.johnsonian.com/

Note that this site refuses to load in any readable fashion at all in Netscrape 4.7x. Looks fine in Internet Exploder, though.