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Saturday 16th 42/41F [In/out] Clear and sunny start. SE sky rather milky. Forecast for cloud later. Time depending on which forecast I trust. None of them!
09.30am Blank disk in WL SC filter.
H-a: Small & fuzzy prom on eastern limb. Strong thermal effects from low sun. Still only 13° altitude.
10.20 am: 46/43F. Back from morning coffee. Sky now covered in persistent vapour trails! Blogger language has switched to US Ingleesh. Should be UK English. UK English now gone as an option.
A clearing has exposed surface detail with yesterday's disturbed area with dark thread [filament] further onto the disk.
10.30am GONG H-a shows small proms on western limb but my etalon is not cooperating. WL still blank.In/out]
10.45am: The dark filament has taken on a seagull form. Tried 15mm for 80x but doesn't show any more than the 20mm for 60x. Wind picking up from SE. Same direction as the sun so getting breezy inside the dome. Thin cloud streaming over from the NW. Thermal shaking on the limb. It's odd how my eye has to tease out the surface detail. The immediate reaction is blank bright red disk. Then the 'orange peel' starts to show up and spreads towards the center.
11.00am: WL+SC now showing the disturbed area very subtly. Even more difficult to see than in H-a! I wait for a brightening of the light patch on the obs wall from the open slit for best results. The shadow edges harden. Then there is a hint that the whole disk is covered in fine texture.
It is probably too early in the year to expect much from such a low solar altitude. I find it best to wobble the image slightly to allow my eye to lock onto the surface texture. The limb looks sharp but the subtle detail is slightly off best focus.
11.20am: Just to be fair, I put the Baader solar foil filter back onto the objective and swapped back to the star diagonal. The Lacerta prism is definitely superior in these very difficult seeing conditions. I don't even have a slow motion focuser.
I want to improve the collimation but will not waste any sunshine hours. It is fascinating to swap eyes at the eyepiece to compare what I see with the other. I normally use my right eye and the sun looks a completely different green to the left eye through the Baader Solar Continuum filter. Which always looks brighter and pure apple green compared to my right eye's much duller and more sage green.
11.30am: 51/46F. Occasional bursts of thermal boiling on the sun's image. I have the south facing door open downstairs to help flush warm air out of the dome. Though it is so breezy now the air should be well mixed. Things have even been blowing off the shelves! A goose has just flown across the sun. Jet blank in H-a.
1140am Sun at 21° altitude. A conspicuous, jet prom has just become visible at my 8.00. Small but narrow. Hardly showing anywhere on Gong yet. Mostly a broader smudge at their 10.00. The nearby filament [on the disk] is surprisingly narrow, sharp and dark. A gust just rotated the entire dome by 1m/ 3'! I cannot believe how effortless it is to rotate the dome with the friction roller and hand crank. Before that I was at my physical limit tying to push it round directly by pressing on the ribs.
10.20 am: 46/43F. Back from morning coffee. Sky now covered in persistent vapour trails! Blogger language has switched to US Ingleesh. Should be UK English. UK English now gone as an option.
A clearing has exposed surface detail with yesterday's disturbed area with dark thread [filament] further onto the disk.
10.30am GONG H-a shows small proms on western limb but my etalon is not cooperating. WL still blank.In/out]
10.45am: The dark filament has taken on a seagull form. Tried 15mm for 80x but doesn't show any more than the 20mm for 60x. Wind picking up from SE. Same direction as the sun so getting breezy inside the dome. Thin cloud streaming over from the NW. Thermal shaking on the limb. It's odd how my eye has to tease out the surface detail. The immediate reaction is blank bright red disk. Then the 'orange peel' starts to show up and spreads towards the center.
11.00am: WL+SC now showing the disturbed area very subtly. Even more difficult to see than in H-a! I wait for a brightening of the light patch on the obs wall from the open slit for best results. The shadow edges harden. Then there is a hint that the whole disk is covered in fine texture.
It is probably too early in the year to expect much from such a low solar altitude. I find it best to wobble the image slightly to allow my eye to lock onto the surface texture. The limb looks sharp but the subtle detail is slightly off best focus.
11.20am: Just to be fair, I put the Baader solar foil filter back onto the objective and swapped back to the star diagonal. The Lacerta prism is definitely superior in these very difficult seeing conditions. I don't even have a slow motion focuser.
I want to improve the collimation but will not waste any sunshine hours. It is fascinating to swap eyes at the eyepiece to compare what I see with the other. I normally use my right eye and the sun looks a completely different green to the left eye through the Baader Solar Continuum filter. Which always looks brighter and pure apple green compared to my right eye's much duller and more sage green.
11.30am: 51/46F. Occasional bursts of thermal boiling on the sun's image. I have the south facing door open downstairs to help flush warm air out of the dome. Though it is so breezy now the air should be well mixed. Things have even been blowing off the shelves! A goose has just flown across the sun. Jet blank in H-a.
1140am Sun at 21° altitude. A conspicuous, jet prom has just become visible at my 8.00. Small but narrow. Hardly showing anywhere on Gong yet. Mostly a broader smudge at their 10.00. The nearby filament [on the disk] is surprisingly narrow, sharp and dark. A gust just rotated the entire dome by 1m/ 3'! I cannot believe how effortless it is to rotate the dome with the friction roller and hand crank. Before that I was at my physical limit tying to push it round directly by pressing on the ribs.
I found my copy of Baxter's "The Sun and the amateur astronomer" yesterday. (1963 edition) His [film] sunspot photography makes me blush at my own pathetic efforts using a handheld, short zoom, digital camera.
Baxter was busy long before H-alpha became accessible remotely affordable for the average amateur. Sidgwick "Amateurs Astronomer's Handbook" has almost nothing on solar observing. I was looking for diagrams of the various types of solar wedge [Herschel prism] online and found almost nothing. I remember being shocked at first seeing the Sun using a home made, Baader solar foil filter on my 90mm f/11 Vixen. Quite a revelation after decades of occasional, fuzzy, eyepiece projection!
12.25pm 56/49F Sun at 22°. It feels much chillier in the dome than earlier when it was almost still!
12.45pm 52/50F Proms on western limb at my 2.00 & 4.00. The 4.00 looks much more interesting. With a pyramidal spike and "smoke" running parallel with the limb. It is so small that it deeds the 15mm 80x to see anything much at all.
13.00pm Cerro Telolo, Chile, is showing the best image so far on GONG @ their 2.00. I just had to fetch my old down jacket to keep warm. The Lacerta heat sink is at 27C/80F.13.30pm Indoors for lunch after quickly adding the Nyloc nuts to the push screws of the 180mm objective cell.
14.00pm 53/50F. Back out to check the collimation. Still full sun but the sky is slightly milky. I was able to overlap all the reflections from the objective surfaces. The image shows how the nut increases the surface area of the plain screw end.
Before collimation ensued I ensured the push screws were central in their thread length to avoid squashing the nuts between the cell and the plywood. I had always planned to cover the bare plywood ring neatly with an example of recycled aluminium cookware but never progressed further.
15.00pm H-alpha now dimmer than before. Sun now only 14° altitude. Did a manual flip before packing up for the day.
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