Jump to content


Photo

Jupiter 12/13/13

  • Please log in to reply
17 replies to this topic

#1 george golitzin

george golitzin

    Surveyor 1

  • *****
  • Posts: 1686
  • Joined: 24 Feb 2006

Posted 14 December 2013 - 04:21 AM

Hi guys—

I’ve had some better views this season, but had not bothered to start sketching yet—Dean seems to have given me a little inspiration.

Seeing was medium soft but with occasional sharp moment. I was out with my 12.5 f/6, finally settling on about 230X (8mm Delos). Time about midnight on the 13th/14th.

NEB showed a braided appearance with a notable bright spot in its middle; two fairly prominent garlands, the following one more pronounced, rose from bulges in the equatorial side of the NEB, with suggestions of another. I’ve shown them a bit too strongly here.

NTB well separated; NNTB suggested by a strong linear concentration with a bright region underneath it (that is, to its north). NPR otherwise featureless.

SEB relatively featureless on this side of the planet, save for some subtle concentrations. STB showed a very fine line suddenly broadening to a wide belt; this was clearly detached from the region to the south by a bright zone; later, this wide part of the belt ended—in all, it was about as long as shown here; SSTB very faintly distinguished from SPR by a lighter zone, quite subtle. A notable concentration, perhaps more oval than bargelike, was seen along its northern edge, preceding the “fat” part of the STB.

The moons were clear disks; Ganymede led, showing no detail (I’ve seen some brighter markings previously this apparition); Io, Europa, Callisto followed.

While I settled on the 8 Delos this evening, I have to say I really enjoyed the view in a barlowed 18mm Celestron Ortho from yesteryear—a symmetrical, not an Abbe—in a 2x Televue barlow it gave a comparable magnification and similar detail to the Delos, with a bit more glare perhaps.

-George

12.5-inch f/6, 230X, UT 8:00 14.12.13. Seeing 3/5, in occasional moments 4/5.

Attached Files



#2 Asbytec

Asbytec

    Guy in a furry hat

  • *****
  • Posts: 8051
  • Joined: 08 Aug 2007
  • Loc: La Union, PI

Posted 14 December 2013 - 04:52 AM

George, looks like you caught Jupiter with BA over the preceding limb (right side) and the GRS approaching the trailing limb (left side.)

That concentration in the SSTeB appears to actually be a tail end fragment of the fat STeB (which ends around the preceding limb with BA) as that belt falls into the SSTeB. There is a darker fragment there. And the STeB does thin out and wrap around to rejoin that fat portion just as you show.

That bright spot in the north, just north of that darker concentration, is a great catch. There is a tiny bright oval there, near System II ~005, amid some lighter cloud, the same lighter NNTeZ feature you show extending into the meridian.

Nice description of the NEB. It does have a braided appearance, though very softly noted and difficult to lock down, IME. There is some rifting, so the bright spot is interesting. Maybe it's a new feature.

Yes, the SEB can be quite featureless, unfortunately. Hard to pull detail out of it away from the GRS. The festooning seems quite complex, too.

Fine job, sir. Good to see you observing, sketching, and reporting.

#3 Rich (RLTYS)

Rich (RLTYS)

    Fly Me to the Moon

  • *****
  • Moderators
  • Posts: 5104
  • Joined: 18 Dec 2004
  • Loc: New York (Long Island)

Posted 14 December 2013 - 08:10 AM

Excellent sketch, thanks for the view.

Rich (RLTYS)

#4 Dean Norris

Dean Norris

    Surveyor 1

  • *****
  • Posts: 1660
  • Joined: 05 Nov 2008
  • Loc: Santa Cruz, Ca

Posted 14 December 2013 - 03:12 PM

George,

Your 12.5" is rockin'. Lots of detail in your sketch. I see you sketched 2 garlands in the EQZ, good catch. The light oval in the NEB looks interesting. I'll be looking for that. I wonder what changes it might undergo? Where the STB ends is where Oval BA is from what I can gather. It does look like a small oval is hanging a little below the STB in your sketch.

Thanks for posting. Dean

#5 azure1961p

azure1961p

    Voyager 1

  • *****
  • Posts: 10225
  • Joined: 17 Jan 2009
  • Loc: USA

Posted 14 December 2013 - 05:57 PM

Nice work George. I'm snowed in here for the weekend so its guys like you making these sketches that allow me to vicariously observe what so much flurry won't allow. The looped festoons and light ellipse in the NEB are my favs.

Pete

#6 Special Ed

Special Ed

    Fly Me to the Moon

  • *****
  • Posts: 6951
  • Joined: 18 May 2003
  • Loc: Greenbrier Co., WV 38N, 80W

Posted 14 December 2013 - 09:51 PM

Hi George,

Very nice and detailed observational sketch. The NEB and EZ look pretty active. I am assuming you have a reflector and preceding is to the left?

#7 Asbytec

Asbytec

    Guy in a furry hat

  • *****
  • Posts: 8051
  • Joined: 08 Aug 2007
  • Loc: La Union, PI

Posted 14 December 2013 - 10:28 PM

You may be right, Ed. Preceding left. That STB is much more distinct preceding that trailing. I was thrown off by that darker concentration thinking it was trailing.

That would put system II closer to 213 (not sure why the calculation differs from above.) That puts oval BA at the beginning of that fat STB. There is a darker concentration preceding it about where it is shown, but it's deeper into the SSTeB than that trailing concentration. That BA was not included shows it's difficulty these days. It's been very difficult to observe.

There is still a dark feature in the north bordered by some lighter cloud. So that remains accurate, and the festoons being loops make determining rotation difficult. Sorry, you may be right. I was confused.

#8 george golitzin

george golitzin

    Surveyor 1

  • *****
  • Posts: 1686
  • Joined: 24 Feb 2006

Posted 15 December 2013 - 12:37 AM

Hi guys--

Many thanks to all of you for your kind comments!

You're right Michael, and I apologize for forgetting to mention it: south is up, and west (preceding edge) is to the left.

So Norme, both you and Dean suggest oval BA is at the left edge of the fat STB, so I flat-out missed it! Hopefully with a little better seeing, I'll be able to pick it up soon. I'll be sure to look carefully next outing.

Again, the festoons drawn here are exaggerated, they were quite subtle at the eyepiece. But consulting my notes from a previous session, I see that after that fat STB section makes it to the preceding limb, a really mongo garland appears, so it was just over the trailing limb at this observation. I wonder if it is still there. There was no missing this guy. Also, apparently I had noticed that white thing in the NTB back in November...

Pete, hope your weather clears soon. Again everybody, thanks, and I look forward to your observations and sketches.

-geo

#9 Asbytec

Asbytec

    Guy in a furry hat

  • *****
  • Posts: 8051
  • Joined: 08 Aug 2007
  • Loc: La Union, PI

Posted 15 December 2013 - 12:52 AM

Yes, with the preceding limb corrected, BA is at the beginning (left edge) of that fat cloud - pretty much embedded in it. It's very hard to see because it's hue does not differ much from that cloud. Good luck, I wish you success. I nearly blew out an eyeball trying to see it. A fleeting, tiny white dot was all I could manage in Ant II seeing. I'd be curious how much better it is in a larger aperture in better conditions. Easier, surely.

Here's an image of nearly the same view, but it's reversed from your sketch. It shows that bright spot in the NEB you mentioned and it makes better sense this was the correct CM with BA near the meridian. You can imagine how hard BA will be. Despite their size, those large white ovals require a steady image, too. In the north, that dark concentration and lighter cloud 'above' it are well represented in your sketch.

#10 Special Ed

Special Ed

    Fly Me to the Moon

  • *****
  • Posts: 6951
  • Joined: 18 May 2003
  • Loc: Greenbrier Co., WV 38N, 80W

Posted 15 December 2013 - 08:50 AM

I agree that Oval BA should be at the preceding end of the fat part of the STB--it's almost always difficult to see visually. I know I've looked right at it in past apparitions and could not detect it.

On the other hand, it was been darker and easier to see last apparition so maybe it will cooperate and darken up again. Who knows the ways of Jove? :)

BTW, whether preceding is presented to the left or right, CM II for 14 Dec. 2013 0800UT is 3.5° (according to WIMP).

#11 george golitzin

george golitzin

    Surveyor 1

  • *****
  • Posts: 1686
  • Joined: 24 Feb 2006

Posted 15 December 2013 - 05:10 PM

That's a beautiful image Emil posted, thanks for pointing me to it Norme. I think I ought to be able to resolve oval BA if the seeing will cooperate just a bit. Happy to see that concentration in the NNTB also, and the subtle lighter zone setting off the SPR, but I missed those pesky ovals in the SSTB. CSC says the seeing might be good tonight, maybe I'll get lucky!

-geo

#12 Asbytec

Asbytec

    Guy in a furry hat

  • *****
  • Posts: 8051
  • Joined: 08 Aug 2007
  • Loc: La Union, PI

Posted 15 December 2013 - 06:35 PM

Yea, George, I nearly blew an eyeball out trying to see BA a couple nights ago. It's so much more difficult than last year. A few weeks ago, it was much easier when it was real close to a brighter oval. Both of them together created something big enough to see readily, but it looked weird. Surely a 12" can do it if Jupiter would just hold still.

Had to ask Eddgie about contrast to help explain why it was so hard. It only put up a faint, hard to see, tiny white spot - about 1" across - amid that cloud. And that was in Ant II maybe Ant I seeing.

Those ovals are tougher than they let on, too, even in good seeing. One might stand out nicely when conditions cooperate, but the other two blend together. They are more difficult that a couple of weeks ago, too. Good luck, clear skies, and maybe another sketch, I hope.

#13 Special Ed

Special Ed

    Fly Me to the Moon

  • *****
  • Posts: 6951
  • Joined: 18 May 2003
  • Loc: Greenbrier Co., WV 38N, 80W

Posted 17 December 2013 - 12:55 PM

I found this image by Vasco da Gama which compares nicely with George's sketch. The System II longitude of the image is 24° which means that Oval BA must have been ~15°-20° System II around the time of George's sketch.

#14 Asbytec

Asbytec

    Guy in a furry hat

  • *****
  • Posts: 8051
  • Joined: 08 Aug 2007
  • Loc: La Union, PI

Posted 17 December 2013 - 08:07 PM

Ed, that's probably more correct. Dunno why I keep getting different figures for that date time group. Maybe fat fingers. According to the maps made on the 13th, it's very near 355 or so. Another check of the CMII is about 4 on 14 Dec at 0800UT according to Ark Sky putting BA somewhere near 15 degrees, probably. Thanks for the correction. The 13th, listed in the title, would have been closer to System II 220.

#15 george golitzin

george golitzin

    Surveyor 1

  • *****
  • Posts: 1686
  • Joined: 24 Feb 2006

Posted 18 December 2013 - 04:43 AM

Nice image from "Vasco," Michael, thanks for that.

I see I've got my "thin" STB lined up with the wrong edge of the "fat" STB! Should be lined up with the equatorial edge, not the southern edge. Ah well, coming in from the cold to make the sketch, I remembered it lined up with one side or the other, but when I went back out to confirm my details, the seeing had gone to heck. The perils of sketching...

#16 Asbytec

Asbytec

    Guy in a furry hat

  • *****
  • Posts: 8051
  • Joined: 08 Aug 2007
  • Loc: La Union, PI

Posted 18 December 2013 - 05:28 AM

Well, yea, the perils of sketching...I got a couple of details misplaced in my own. Just so you know you're not alone.

#17 Special Ed

Special Ed

    Fly Me to the Moon

  • *****
  • Posts: 6951
  • Joined: 18 May 2003
  • Loc: Greenbrier Co., WV 38N, 80W

Posted 18 December 2013 - 10:43 AM

George, your drawing holds up very well against Vasco's image. :waytogo:

My main purpose is to try and use these observations to give people an idea of where Oval BA is so they can look for it. Of course this location is going to change over time but for now somewhere between Sys II 4° and Sys II 24° should put it on or near the central meridian.

#18 Asbytec

Asbytec

    Guy in a furry hat

  • *****
  • Posts: 8051
  • Joined: 08 Aug 2007
  • Loc: La Union, PI

Posted 19 December 2013 - 08:15 AM

Michael, it would be interesting have others reporting on BA with varying aapertures and conditions. In very good seeing I found it extremely difficult. The problem seems to be its very low contrast with the embedded cloud. BA does have a small brighter center, this may help it stand out. Its tougher than last year when it was set against lighter cloud tops.

As difficult as it is, its a good test of both man and machine and of conditions. It nearly cost me an eyeball just to glimpse a tiny, fleeting white spot about as tough and the same size as a white oval. I really suspect BA's lighter core gave it just enough contrast to be seen during the best moments. It certainly helps to know where it is, its easy to miss.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics