Some observing - at long last !!

davidm61 · Post by **davidm61** » Sun Sep 28, 2008 3:30 pm

Hello

At long last I've finally managed to get out and do some observing - the weather and work commitments having prevented any observing for some time. That said the viewing conditions were not exactly good here in Manchester, with very few stars actually visible to the naked eye, and those that could be seen were 'twinkling' away. I suspect that there was either a lot of moisture in the atmosphere or else very high, very fine cloud. This was the case last night (Saturday 27 Sept) and the previous weekend. Can anyone confirm if the poor seeing was down to moisture or very high, fine cloud? Or was it just me, being out of practice

At least the slightly hazy conditions had one benefit, in that my views of Jupiter were good, in fact given how low it is, I enjoyed very good views through my newly aquired Meade ETX 125. Four of Jupiters larger moons were also visible, and the main cloud bands, along with other surface features were also readily apparent.

The main thing though, is that I finally got back outside and enjoyed some observing - and had first light with my new scope.

coldfieldboundary · Post by **coldfieldboundary** » Mon Sep 29, 2008 10:20 am

both, there is moisture and there are hazy clouds...

but not only planets are better visible this way, also double stars!

gr

Lady Isabella · Post by **Lady Isabella** » Mon Sep 29, 2008 1:35 pm

Hi davidm61

For me, Saturday night was the best night so far this year for seeing on Jupiter. Six belts, several zones and detail within the Equatorial belts.
Last night was not quite as good, but the Great Red Spot was easily picked-up.

goodtime · Post by **goodtime** » Mon Sep 29, 2008 6:00 pm

Wow, I'm impressed Lady Isabella, what scope are you using?

I count myself lucky when I can make out any bands, I guess a 660 mm focal length is just not going to make a good planetary scope.

davidm61 · Post by **davidm61** » Mon Sep 29, 2008 7:48 pm

Hello

With the ETX 125 the bands on Jupiter are readily visible, not just the main belts, but other smaller ones as well. The GRS is also visible in the ETX 125. So you don't need a big scope to see the cloud banding and GRS, and when I first started back into astronomy I had a 60mm, F/750 telescope through which the two main equitorial bands could be seen, along with three or four of the moons.

I note that Goodtime lists the Celestron 102. I also have a Nextstar 102SLT and it is quite capable of showing some detail on Jupiter, as well as Saturns rings and so on. You may have to use a 2x barlow to up the magnification a bit, (but not too much or you'll degrade the view - experiment to find the best magnification for the conditions), but the 102 is a capable instrument. When I was viewing Jupiter the other night I used a 9mm LER lens, which on the ETX translates to a magnification of x211.

Just as an aside, I have an 8" LX90 as well. This is a very capable scope, producing really good views of both planets, moon and deep sky objects. Yet for the planetary and lunar work the ETX, (because it's a Maksutov), despite having a smaller aperture, is far superior to the LX90. So in this case size isn't everything.

Here's an image of Jupiter that I did the other year.

The point of showing this is that most of what is visible in the image was also apperant at the lens as well.

goodtime · Post by **goodtime** » Mon Sep 29, 2008 8:22 pm

I didn't mean that I couldn't see any detail, I was really just remarking that I can't get Jupiter up to a reasonable size in the eyepiece even with a 2x Barlow and 6 mm eyepiece, whereas Lady Isabella can see many bands, plus detail in the bands! On a good night I can see... oh, maybe 5 bands. The Galilean moons are no problem, they shouldn't be a problem in any scope, I can see them in my binoculars.

I didn't buy my scope (102SLT) to do planetary work, I bought it for its short focal length, wide-field capability, at which it excels. Most people indicate their telescope system in their signature, Lady Isabella did not, I was curious...

Cliff · Post by **Cliff** » Mon Sep 29, 2008 9:48 pm

Dear DavidM61
Just to confirm that my recent viewing from the North side of Manchester as been much the same that you describe - grotty to terrible !
when I first saw the Jupiter pic you just displayed, I was quite amazed because it was far better than anything I got last night (before the clouds came in again). I felt quite relieved when I saw your comment that your jupiter pic was takein in another year.
Having been clouded out for what seemed forever, I actually set up a scope on five occasions in just over a week recently, twice clouded out without managing any views at at all, once got a brief view of Jupiter. another time spent 2 hours getting 50 x 30second images of M27 - which were rubbish, because of thehazy conditions you mentioned, last night I got some mediocre images of Jupiter.
By the way, I agree with coldfieldboundary that thin cloud can sometimes apparently enhance visual views of planets. However, when it comes to imaging planets I personally seem to find that any haze or thin cloud can spoil the image. It seems to me that sky transparency can affect planetary images more adversely than it does visually observation.
The thin cloud sometimes seem to enhace planetary views (possibly the human eye can compensate for a slight loss of the the planets brightness due to the cloud)., whilst the loss of brightness brightness may be more detrimental imaging because the need to increase exposure (or brightness gain) takes the edge off images.
Best of luck from Cliff

Lady Isabella · Post by **Lady Isabella** » Mon Sep 29, 2008 9:54 pm

goodtime wrote:Wow, I'm impressed Lady Isabella, what scope are you using?

Hi Goodtime

I was using the following Apo telescopes, 102mm f/8 and 130mm f/7.7.

Lady Isabella · Post by **Lady Isabella** » Mon Sep 29, 2008 10:13 pm

[quote="davidm61"]
Just as an aside, I have an 8" LX90 as well. This is a very capable scope, producing really good views of both planets, moon and deep sky objects. Yet for the planetary and lunar work the ETX, (because it's a Maksutov), despite having a smaller aperture, is far superior to the LX90. So in this case size isn't everything.
quote]

Hi davidm61

Yes, while larger scopes give you more resolution, in order to see the extra detail, one must use magnification. Typically around 30x per inch
for the planets. For Jupiter with an 8 inch means a magnification of 240x.
Jupiter tends to handle magnification less well as the other planets, and it would have to be a very good night of seeing to get the benefit from the larger scope. So with a smaller scope, you can tend to get better visual views of the planet. With imaging, aperture wins.

The following article makes an interesting read:
http://www.brayebrookobservatory.org/Br ... tions.html

goodtime · Post by **goodtime** » Mon Sep 29, 2008 11:55 pm

Lady Isabella wrote: The following article makes an interesting read:
http://www.brayebrookobservatory.org/Br ... tions.html

That article is indeed a fascinating read. I'll have to try using high powers (if the sky clears again), I've been wanting an excuse to buy a good Barlow. I almost always use my 102SLT at 44x or less, usually at 16.5x with my favorite eyepiece, a 2" 40mm 65° Erfle. With the Erfle I get a real field of view of almost 4°, it's great for clusters, many DSOs, the moon...

Anyway, thanks for the pointer to the article, it's a good read.

davidm61 · Post by **davidm61** » Tue Sep 30, 2008 7:17 pm

Hello

Lady Isabella, many thanks for the link to a very informative article.

Goodtime, I agree totally with your comments on the 102SLT, and it's abilities as a wide field instrument, which as you say is it's advertised purpose. I tried a high magnification on mine when viewing Saturn earlier in the year and was pleasently surprised with the result.

Cliff, sorry that you too are in the same terrible viewing boat as me. That said, these appalling viewing conditions can't last for ever (can they?). What I want is a return to Winters such as those in 1999, 2000 and 2001. Proper cold days and really crisp, cold and clear nights.

Clear skies.