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Great Beige Spot?

Started by darrencrooks, 03/30/2003 02:02AM
Posted 03/30/2003 02:02AM Opening Post
Well, I finally got a view of the Great Red Spot. But frankly, there's nothing red about it. It was closer to tan -- in fact, it really didn't have much colour difference between it and the South Equatorial Belt beside which it appeared.

I should preface this by saying that Wednesday March 26 was the first night I had been able to use the Plossls I had purchased here a week previously -- it having been overcast every night since then! I finally had some decent eyepeices for my cheap department store Bushnell 4.5" Newt, and I was anxious to try them out.

At first I was dissapointed -- was I actually seeing double images of bright starts and Jupiter? Horrors. But that was as a result of not letting the scope cool. The 20mm (45X) had a 10 degree wider apparent FOV than the 20mm that came with the scope, and I could almost fit Jupiter in with M44 in the same view. That was a pretty sight.

I also noticed that M44 seemed brighter and crisper than with my original eyepiece. Altogether, I was quite pleased with the improvement.

Even in combination with my crummy 3X Barlow (again, original equipment), the images were considerably sharper and more contrasty. For instance, I was able to clearly resolve the Cassini division (which had heretofore been nothing more than a faint suggestion) and even saw a dark band on Saturn itself.

Jupiter gave me some very clear views of the polar regions and both equatorial belts. I was able to resolve the SEB into two distinct bands when the image settled down. And I finally got a view of the GRS -- looking like a tan swirl in the SEB, accented by a darkish eyebrow south of it. But there was little contrast between the colours on any of the features on the Jovian disk -- I got two shades: off-white and tan. The great red spot was no redder than anything else. Maybe I need more aperture to get better colour contrast. Maybe viewing from my light-bathed driveway had something to do with it.

Well, that's about it for now. I'm awaiting the deilvery of yet another Plossl, a Meade Series 4000 7mm that I purchased here. That way, I can dispense with the crummy Barlow altogether.

Please excuse the long-windedness. I've only been using this telscope for three months, and every new image is an adventure. Besides, it is (alas) overcast once again, so this is the next best thing.

Clear nights ... dark sites,
Darren


Posted 03/30/2003 07:17AM #1
Darren,

Congratulations on observing Jupiter using your new eyepieces. You have done well to improve your eyepiece set. It makes all the difference between seeing detail on the planets.

As you point out the Great Red Spot (GRS) is not always it's namesake color. The last time the GRS appeared reddish in color, to my eyes, was back in 1990 when the SEB disappeared. Before then the GRS was prominent in 1975 and in the 1960's. It currently is reported to be orange-red in color by various observers.

A factor that may not bring out the delicate color of the GRS is your aperture. You normally need a 6-inch refractor or 8-inch reflector to really notice color within the GRS. A smaller aperture will detect color but the reduced (relative to a larger aperture as mentioned) light transmission will diffuse the hue visible. Please keep observing with your excellent instrument as it has much to offer on the Moon and planets.

The best of luck in your future observations.

Carlos
Posted 03/30/2003 04:37PM #2
Hi, Darren.

Based on your brief descriptions of the images you obtained of both Jupiter and Saturn, I get the following impressions:
-your reflector is doing pretty darned well
-you're a good observer

No, the GRS aint much red, these days, but it sounds like you're seeing detail which suggests good performance for a 4.5-inch reflector. Keep staring at that big monster Jupiter -- more details along the belts and zones (and *within* them) might just reveal themselves. Are you able to see irregularities along the SEB and/or NEB (other than that GRS "hollow" you reported? Perhaps the edges of the belts are somewhat wavy or ragged, along some sections.

Once you get a good view of a shadow transit, I'd like to hear your impressions of it.

Tan, cream, grey, and maybe some grey-blue. That's par for the course, in a good 3- to 6-inch scope. Again, it sounds like the Bushnell is doing a good job.

As you view Saturn more and more, keep note of its rings -- their colors, which are brighter. And check out Saturn's polar region, too. I'd enjoy reading your impressions of the views. It's always a real kick when I hear about folks having success and doing well with infamous "cheap department store" scopes. It's good to know that there *are* good ones out there, Bushnells and Tascos and the like, which have good primaries and objectives, and which prove to be quite enjoyable and satisfying in use.

Best wishes and continued grins and success.
-Dan