Posted 10 May 2013 - 05:55 PM
I’ve really learned a lot from this tread.
With a new secondary and insanely great seeing for VT I was able for the first time on Saturn to boost the magnification in my 10” Dob to around 400x, 5/14/13. Because of this thread I was trying really hard to see the Encke Division. Never did manage it.
The interesting thing is that I kept seeing a darker line bisecting the A ring. I knew the Gap was near the outer edge of the ring so I just dismissed what I saw as an optical aberration. At that time I didn’t know there was a Encke Minima, or that there was a difference between the two. But now I do!
I also realized that with the excellent mirrors I now have, I’m really going to have to do my home work on what’s possible to observe on Saturn and really knuckle down and pay more attention. I didn’t have any reference material with me because my previous viewings were “nice to look at” but not detail rich. That nights quick look turned into two hours of “WOW I can see all sorts of banding”, and “I wish I knew more about the finer details of ring structure”!
Brian I wish you all the luck. As I mentioned in another post its still a great view without the E-gap (heh take THAT Bill!). Still how can you NOT look for it? You have the golden key aperture apparently under the better circumstances. Hang in there and I look forward to your reports. And u kno how it is - even a negative result is a positive observation!
Posted 11 May 2013 - 07:58 AM
I can see the A ring darkening easily, thought we glimpsed the Encke division in a 16" F5 Cave(backyard observatory of a friend of a friend)but the seeing went sour that evening.
Great mirror in that Cave, but seeing never cooperated when we went to observe with him. (The beer probably didn't help either)
Posted 29 May 2013 - 06:44 AM
An excellent imager in South America with a C8 has successfully imaged Enckes almost to the point I thought it was via C11 or C14. His name is
Rafael Defavari and he's something on par with Damien Peach with an 8.
I thought it shed light on the Enckes Division question with an 8". Wether or not the eye can detect the low levels of contrast Rafael has is still a point of contention among some, but with the imager its at least there as a line on SOME level. I'm to locate the smallest aperture that can still image it but it looks like it ends with c8. I'd wonder if a 150 Mak in Rafael's hands (and seeing) would show it but for now there's no one making pix to his level of clarity as the rings are wrought with ringing effects and softness comparably.
Here's the link:
Posted 29 May 2013 - 06:59 AM
Posted 29 May 2013 - 09:11 AM
Your description is of the Encke Minima, a broad low contrast feature roughly in the middle of the A-Ring. I would describe this feature as trivial in a 10-inch aperture. It was regularly visible in my old, contrast-challenged Meade Starfinder 10-inch equatorial Newtonian. Based on that experience, I see no reason to doubt it can be observed in a good 6-inch aperture.
Bill in Flag [/quote]
Recently I read an article in the latest Astronomy magazine where the author said he'd seen Encke's Minima in a 4" reflector.
Posted 31 May 2013 - 12:04 AM
As stated ealier in this thread, I have seen it twice in my 9" Clark.
Posted 18 June 2013 - 12:47 AM