10 replies to this topic

[Sasa]

I never look at Jupiter orientation before my observations. Basically it is a random process. From some reason, I was very unlucky. I made more than 20 sketches before running on GRS again. Here it is through 82mm refractor. It was quite difficult to spot and much fainter from what I remember:

 

[frank5817]

Alexander,

 

The last dozen or so looks I had over that number of days of Jupiter - no GRS. I thought I was repelling it.

 

Nice sketch and nice capture of the GRS.

frank

[Sasa]

Thanks for all the likes. 

 

For fun, I was just trying to estimate what are the chances to have 20 consecutive observations of Jupiter without GRS. My first very naive estimate was that it is half-on-half to see the GRS as one always see half of the planet surface. This would give it a probability one-in-million for the case, as (1:2)^20 = (1:2^10)^2~1000^2=1 000 000. This would be really unlikely.

 

But GRS is hard to spot near the edge. The effective surface when it could be spotted in small apertures would be probably smaller. I check all my sketches and counted 71 sketches with GRS out of 286. That would give a probability to see GRS in about one case out of four. And the probability for not to see GRS in 20 observations would be (3:4)^20~1:300. This sounds more reasonable.

 

Frank, in your case for 12 observations without GRS, the odds are (3:4)^12~1:30. This is a bad luck but it is  happening relatively often.

[Astrojensen]

 

It was quite difficult to spot and much fainter from what I remember:

I've seen GRS quite a few times this season, with telescopes from 63mm to 152mm, and it hasn't struck me as being particularly faint. Even in the little 63mm Zeiss, I can see its orange-red color, albeit only faintly. Magnifications from 84x to 105x. In the Meniscas 150, despite its large secondary mirror, the color is unmistakable. 

 

What has impressed me during this opposition, is the massive activitity and HUGE festoons in the equatorial zone.

 

 

Clear skies!

Thomas, Denmark 

[Sasa]

The GRS looked to me quite blurred, it was very difficult to spot the edges. May be, I run just on bad conditions. The view was quite still at 133x but this could be just a feeling. Sometimes there is no detail even when the air is steady. There was definitely some haze in the air and the lens was at the end of sketching slightly covered by dew

 

Yes, the equatorial part is busy, some festoons rivals with the contrast reqular belts (like tonight).

[Astrojensen]

The GRS looked to me quite blurred, it was very difficult to spot the edges. May be, I run just on bad conditions. 

I think so. I recently observed it with the APM 152ED and GRS appeared quite well-defined to me, like it has also done in the Meniscas 150. 

 

 

Clear skies!

Thomas, Denmark

[Sasa]

Tonight I run on similar rotation, again with GRS well placed. In 100mm it was much easier to notice, I could even see its orange color with some concetration (no color in 82mm last time). Equatorial zone was again very busy. In addition there was some interesting line norht of NEB.

 

[Special Ed]

Nice looking observational sketches, Alexander.     

 

Your difficulty with seeing the GRS in your January 19th sketch was probably due to conditions, the placement of the feature near the limb, and the fact that the GRS is shrinking.

 

In your January 26th sketch, you appear to have captured the NTB outbreak where it has spread into the NEBn.  Nice work!

[Sasa]

Thanks Ed. Tonight I made quick sketch of Jupiter quickly before arrival of clouds. I was lucky, and the planet was in similar rotation again. GRS was very difficult to spot this time, it was closer to the limb, seeing was much worse, and there was much more humidity in the air. Still I was able to observe similar level of details, including a hint of NTB break near the limb:

 

[JMSchwartz]

Very nice sketch and observation. Congratulations on getting the red spot. Timing, is everything. planning it during the best peak hours of the rotational axis across the disk, there's a lot more available. These days

Sky safari has a lot of options for a observation list it can give you the exact time. The red spot is visible. I never use it cuz. I don't own it, but but if you look enough, you'll see the red spot eventually.

Clear sky always Jon

[bphaneuf]

Finally saw if for the first time last night!  It was in much the same location as your excellent sketch and just as faint and elusive as you describe.  Had some young visitors to the observatory last night and Jupiter stole the show.  Fortunately had steady skies and their much younger eyes, after a little lesson in averted vision, were able to pick it out.