26 replies to this topic

[eblanken]

Hi Darren,

 

Just a note of encouragement - I like your new setup - I will never go as far down the 589nm +/- 4nm (Na+/-) road as you, but I do like my Na Quark, as it is a nice color of Yellow for the Sun !!! You have my full support and encouragement - I'm going to re-read your post as I find time to more fully digest.

 

Best,

 

Ed

Edited by eblanken, 25 September 2024 - 11:20 PM.

[ch-viladrich]

Okay, here's a brief follow-up on the 45-minute solar observations taken at lunchtime!

 

24 Sept 2024, 1855-1942 UT:

 

Darren's pretty nifty 152mm SST (Sodium-I Solar Telescope  ) at ~70X...(13mm NT6)

 

• Wedge tests: As suspected, confirmed that the difference IS noticeable, not so much in detail, but BRIGHTNESS. I was able to set to pretty much max throughput on the Baader Wedge, but had more light still available in the Lacerta - this is more of a reference when transparency drops, but esp. for >90X observations, where a bit more light MIGHT be needed. I was not able to test this today - seeing was variable with only short (10-15s at a time) steady periods. 7/10 average, but did hit 9/10 at times. (hence the 70X limit)
• IMO, both showed excellent details when seeing steadied. I did a ~15 minute run with each, and left the Lacerta in to finish the session. Not a fully comprehensive comparison, admittedly, but that was all I had for lunch window, and seeing dropped around 1935 to getting pretty turbulent - enough to affect most of the finer structural stuff... Likely would have settled, later I am sure, but oh well...
• One thing I forgot to mention, which during testing between the wedges was notable (thanks Gary S!), was that at certain intensity levels, the view begins to "saturate" a bit - one sees this also with WL observing, but the fine structure "window" of settings affects shadings/granulation more significantly, and it starts to drop - likely a contrast/brightness issue; if run on the high side of this but not maximum quite yet, (say 80% to maximum), the central plage starts to wash out a bit. granulation still holds, but the lesser developed plage, visible at lower levels of illumination, start to become harder to resolve. I noticed this during the testing, because I was playing with intensities to evaluate differences between the wedges. I did not check this yet (will next time), but I suspect that under higher powers, say 90-100+, that this would drop back to more nominal and permit finely resolved viewing. I did see this on Saturday when I trimmed the polarizer axis over ~8-10^o but left it when an optimal level was reached. Today this was easier to see, given seeing changes as well. Under ideal, nearly perfect seeing, this may be present to a lesser degree, but since i have only had this "SST" out for several days so far, I need more "data" in that regard to be certain how sensitive these settings really are to the overall view. I think I could run THIS filter with the Baader sans polarizer  like I did on my 105, and get good results. Will check when I have a chance. 
• The best seeing just happened to be during the Lacerta phase. Not by design, but I suspect equilibration may not have been achieved fully during the Baader wedge test. I had planned to re-check until seeing and time constraints decided for me. Now, onto the goodies seen mostly in both - just the interesting top three highlights:
• For brevity, I saw three very interesting things despite the variable seeing:

 

• (1) - two hot spots and significant visible plage structure further north than I usually notice when doing solar prior to this SST view. I estimate closer to 60^o north; I verified this with HV's angular tool: 331-333^o @ 0.875 R_sol. For reference 1.0 R_sol is limb edge, 0 = disk center. North on sun is 0^o:

60degree N plage.jpg

 

60N Hot spots enhanced.jpg

 

(AIA 1700 enhanced for better view of details not as easy to see in HMI channel alone: HMI@60%, AIA1700@100%)

 

• (2) - A central disk region of facular plage that looked a bit like a 3-toed "Cat's Claw"; had nearly-parallel arches and plage-edge shadings which were rather prominent during better/best seeing:

CatsClaw_Plage_AIA1700Enhanced.jpg

 

(AIA1700 enhanced image again to show structure better).

 

• (3) - Eastern Limb edge - +/- 40^o or so: Facular plage during session was evident to over 1/2 way to the disk center, or at least from 1 < R_sol < ~0.60. A lot of the western structures connected heavily with AR 3836, the new region rotating into view, plage common though AR 3835, and some plage with very interesting shaded edges nearer AR 3834, too. The edge-shaded plage boundary looked like someone with charcoal had lightly brushed the disk accidently with a finger. Really neat!  I could also JUST make out (seeing affected this) a bright region on the leading umbra of AR 3834, on the northern side, approx. size was maybe... ~30% of the umbral area - hard to make out as seeing made it a challenge to see this as well as I have seen on the past Saturday. May have been better later today, but partial cloud has plagued our skies. No joy for a rematch today!

Still, some interesting results, and nifty views, which are rather unique to observing the sun in 589nm NB light. The 152 SST wins again! 

 

Cheers and CS,

 

Darren

Hi Darren,

 

Just for clarification about some words that can be misleading :

 

(1) What you called "hot spot with plages" in image (1) are indeed facular plages of smaller sizes.

The intensity of facular plages depends on the density of faculae in the facular plages. So, some areas of facular plages can appear brighter (when density of faculae is higher).

As a reminder, it takes a 250 to 300 mm aperture telescope to actually see individual faculaes.

 

(2) In image (2), I can't see any "anomalies" in the granulation or facular plages.

 

Also in image (2), the use of the word "arch" could be confusing since it could suggest a 3D structure. Maybe "curved" or "bent" would be more appropriate.

 

Sorry for spliting hair in about wording, but wording could be misleading as thery might suggest physical interpretation.

 

There is a textbook example of that with the "Mars canals" affair. Schiaparelli used the itialian word "canali" which means "channels" and does not implies any "intelligence" building artificial structure. This was unfortunately translated (in French and English) by canals, which imples some "civilization" actually building something.

 

Another example I like is the "bridge" seen by Wilkins on the Moon. There was of course nothing like a bridge, just projected shadows on the surface of a crater.

 

And more important, good to know you've received your 3 nm filter :-)