Mars and Saturn
After more than three rainy cloudy weeks weather finally cleared on June 8th. The evening sky was cloudless. Winds died down. Humidity was low and temperature mild. Overhead a thin crescent Moon, Jupiter, Mars, and Saturn were on display from west to east. I couldn't ask for better conditions for some planetary imaging.
Unfortunately, my laptop chose this night to malfunction. Everything worked normally just hours before, but, for some incomprehensible reason, the keyboard and touchpad were unresponsive when I started the computer. More than an hour of prime observing time was wasted searching for solutions to the problem. This keyboard problem happened once before. I foolishly failed to record the solution I found at that time. So I had to once again wade through a jungle of irrelevant tips on Google before chancing upon the right fix. The keyboard malfunction happens sometimes after updates are installed. I think some updates fail to complete, and there's no warning this has happened. I had to disable the "fast startup" option (hidden under several menu items), then restart. Eventually, the keyboard came back to life, but by then the Moon had set and Jupiter was low in the sky.
I began imaging bright Mars at 11:50 pm with a newly acquired 4X Barlow lens. Then I switched to a 3X Barlow lens. The best results are below. The first image was made with the 4X Barlow. The second image was made with the 3X Barlow. Which do you think is better?
Both images show the same Martian features, although the bright white south polar hood on the bottom seems more visible in the second 3X image. North is up and the polar axis is tilted to the right. A very tiny north polar cap is barely visible as a slight brightening on the 3X image but not on the 4X image. The dark boot-like feature in the north is Mare Acidalium. One thing is certain: these processed images show much more detail than my naked eye could perceive in the eyepiece!
I moved on to Saturn next. Once again, the 4X image is first below, 3X image second.
The north polar region of Saturn is on top casting a bit of shadow on the rings behind. The outer gray A ring and bright white inner B ring are separated by the dark Cassini Division. This time, the 4X image seems slightly better to me because the Encke Gap is barely visible on the left and right sides of the A ring. The Saturn images came out fairly well considering how low Saturn was in the sky.
Near midnight I removed the camera, put in an eyepiece, and did a bit of visual observing. Temperature had dropped rapidly into the mid 50's in the dry, clear air. After looking at some globular clusters, open clusters, and double stars, I got chilled and felt exhausted, so, reluctantly, I had to give up. I would have done more visual observing if I hadn't spent more than an hour earlier solving computer problems!
Saturday, June 11, 2016
Wednesday, June 1, 2016
Plantations
Historical Houses
Although we often drive past several old plantations along the James River near our home in Williamsburg, we've never managed to visit one until recently. A knowledgeable local friend recommended Westover Plantation, so we began our exploration there. The first picture below shows a tree-lined portion of the long dirt entrance drive approaching the main house.
Plantation seems to be a fancy word for farm. Westover is still a working farm, as you can see from the crops growing on both sides of the road in the previous picture. This is a very lovely farm indeed, with many beautifully kept verdant fields all around.
After paying the entrance fee we walked along a shady path towards the side of the house facing the James River.
This was our first view of the house.
The next view from the south lawn shows the full extent of the house. The center portion was built in approximately 1730 by William Byrd II.
Next is a view of the river from the south lawn. I want to say this is the back lawn, but I'm not sure which side of the house is considered the front.
A walk out toward the river reveals this scene along the western riverbank.
The opposite side of the house, the north side, has a more elaborate door and an impressive gate at the entrance. So, maybe, this is the front of the house. The gate has William Byrd's initials in the iron work over the gate - a bit more impressive than the unremarkable welcome mat by my front door.
An elaborate garden lies next to the house with paths for a shady evening stroll. Wouldn't that be nice, you think, to stroll through your own private garden like this one on a pleasant day? Wait a minute! Who built and maintained this garden? Who constantly weeded, trimmed, and planted? Certainly not William Byrd II, master of the house! He and his guests just strolled through the garden conversing after dinner while slaves and servants responsible for the garden hoped to get a few hours rest after a hard working day.
One garden path leads to the centrally placed tomb of the house's builder, William Byrd II, who lived from 1674 to 1744.
How many of us would describe our education as "happy proficiency in polite and various learning"? Here is a portrait of the tomb's occupant, William Byrd II.
Apparently, William Byrd II was not a paragon of moral virtue despite being described as a "well-bred gentleman and polite companion." His behavior toward women and servants was particularly bad. Some humility might have been useful. Here's a guy who has a monument to himself on the grounds of his own house. I find this bizarre!
The old Westover Church once existed a quarter mile west of the house along the river. We walked down the original carriage path to that site where an ancient cemetery still remains. One of the graves there is from 1637!
Roughly two miles up river from the Westover Plantation is the Berkeley Plantation where we visited next. Berkeley has made more effort to accommodate visitors than Westover. Berkeley charged a higher admission fee, but the house was open. Berkeley had guided tours, a gift shop, restrooms, and more visitors than Westover. The Westover mansion was closed, and we walked around the Westover grounds in quiet solitude guided only by a brochure.
Berkeley has been the site of much American history beginning with the first settlers in 1619 before the present house was built. Later, George Washington and Thomas Jefferson were guests in the house. Two American presidents and a signer of the Declaration of Independance came from the Harrison family who built, owned, and lived in the house. Benedict Arnold looted the house during the Revolution. Abraham Lincoln visited when the entire Union army was camped here during the Civil War.
The north side of the Berkeley mansion, completed in 1726, is seen through the gates below.
A long path starts from the south side of the house as seen in the next picture.
The fine gravel path leads away from the house down toward the river.
At the end of the path the view opens to a magnificent scene.
Imagine this is your lawn, and you sit here on a bench while cool summer breezes blow from the river ahead. How lovely! But after a while you think, "Hey. Who mows this enormous lawn? Who maintains the crops and the many gardens, trees, and shrubs?" In modern times the answer is a crew of workers who must be paid and managed - a nightmare to my mind. In colonial times it would have been many slaves and servants - a moral nightmare. This is a nice place to visit, but I'd rather live without servants in a modest small house where I can take care of most chores myself!
Although we often drive past several old plantations along the James River near our home in Williamsburg, we've never managed to visit one until recently. A knowledgeable local friend recommended Westover Plantation, so we began our exploration there. The first picture below shows a tree-lined portion of the long dirt entrance drive approaching the main house.
Plantation seems to be a fancy word for farm. Westover is still a working farm, as you can see from the crops growing on both sides of the road in the previous picture. This is a very lovely farm indeed, with many beautifully kept verdant fields all around.
After paying the entrance fee we walked along a shady path towards the side of the house facing the James River.
This was our first view of the house.
The next view from the south lawn shows the full extent of the house. The center portion was built in approximately 1730 by William Byrd II.
Next is a view of the river from the south lawn. I want to say this is the back lawn, but I'm not sure which side of the house is considered the front.
A walk out toward the river reveals this scene along the western riverbank.
The opposite side of the house, the north side, has a more elaborate door and an impressive gate at the entrance. So, maybe, this is the front of the house. The gate has William Byrd's initials in the iron work over the gate - a bit more impressive than the unremarkable welcome mat by my front door.
An elaborate garden lies next to the house with paths for a shady evening stroll. Wouldn't that be nice, you think, to stroll through your own private garden like this one on a pleasant day? Wait a minute! Who built and maintained this garden? Who constantly weeded, trimmed, and planted? Certainly not William Byrd II, master of the house! He and his guests just strolled through the garden conversing after dinner while slaves and servants responsible for the garden hoped to get a few hours rest after a hard working day.
One garden path leads to the centrally placed tomb of the house's builder, William Byrd II, who lived from 1674 to 1744.
Carved on the tomb is a barely legible epitaph containing flowery prose so fascinating and alien to me. Here are two examples:
"Being born to one of the amplest fortunes in this country, he was sent early to England for his education, where, under the care and instruction of Sir Robert Southwell, and ever favored with his particular instruction, he made happy proficiency in polite and various learning;"
"To all this was added a great elegance of taste and life,
the well-bred gentleman and polite companion, the splendid economist and
proudest father of a family with the constant enemy of all exorbitant power and
hearty friend to the liberties of his country."
How many of us would describe our education as "happy proficiency in polite and various learning"? Here is a portrait of the tomb's occupant, William Byrd II.
Apparently, William Byrd II was not a paragon of moral virtue despite being described as a "well-bred gentleman and polite companion." His behavior toward women and servants was particularly bad. Some humility might have been useful. Here's a guy who has a monument to himself on the grounds of his own house. I find this bizarre!
The old Westover Church once existed a quarter mile west of the house along the river. We walked down the original carriage path to that site where an ancient cemetery still remains. One of the graves there is from 1637!
Roughly two miles up river from the Westover Plantation is the Berkeley Plantation where we visited next. Berkeley has made more effort to accommodate visitors than Westover. Berkeley charged a higher admission fee, but the house was open. Berkeley had guided tours, a gift shop, restrooms, and more visitors than Westover. The Westover mansion was closed, and we walked around the Westover grounds in quiet solitude guided only by a brochure.
Berkeley has been the site of much American history beginning with the first settlers in 1619 before the present house was built. Later, George Washington and Thomas Jefferson were guests in the house. Two American presidents and a signer of the Declaration of Independance came from the Harrison family who built, owned, and lived in the house. Benedict Arnold looted the house during the Revolution. Abraham Lincoln visited when the entire Union army was camped here during the Civil War.
The north side of the Berkeley mansion, completed in 1726, is seen through the gates below.
A long path starts from the south side of the house as seen in the next picture.
The fine gravel path leads away from the house down toward the river.
At the end of the path the view opens to a magnificent scene.
Imagine this is your lawn, and you sit here on a bench while cool summer breezes blow from the river ahead. How lovely! But after a while you think, "Hey. Who mows this enormous lawn? Who maintains the crops and the many gardens, trees, and shrubs?" In modern times the answer is a crew of workers who must be paid and managed - a nightmare to my mind. In colonial times it would have been many slaves and servants - a moral nightmare. This is a nice place to visit, but I'd rather live without servants in a modest small house where I can take care of most chores myself!
Tuesday, May 24, 2016
Rain and Sun
Rainbow and Sunspots
Sunlight is rare these wet days in Williamsburg. My lawn has never been greener. Although clouds and rain make solar observing impossible, occasionally, the Sun does break through. Late in the day on May 14th an amazing intense rainbow appeared behind my house. Unfortunately, the 6-panel mosaic below failed to capture the very top of the secondary rainbow. I wish I had raised the camera a bit higher! (Click on the image for a larger view.)
The primary rainbow is very bright and shows up nicely against dark background clouds. The higher secondary rainbow is dimmer with colors arrayed in opposite order compared to the primary rainbow. Inside the primary rainbow supernumerary bands are seen, particularly near the top of the arch. View the enlarged image to see the supernumerary bands more clearly. This is the best rainbow I've ever seen!
Two days after the rainbow's appearance the sky finally cleared for several hours. Viewing conditions were nearly ideal with gentle puffs of wind and temperatures in the mid to upper 60's. Seeing was good as I began solar imaging at about 2:00 pm EDT.
The Sun finally showed a few significant features which are displayed in the following 40-panel mosaic made with a 5X Barlow lens. On the left, large sunspot 2546 is located near an accompanying white active area. On the right is smaller sunspot 2544 with its own active area. The large prominence on the upper left limb was particularly bright in the eyepiece. (Click on the image for a larger view.)
The previous image has been reduced to one third of its original size. The full-sized image is a 13.4 MB monster measuring an amazing 6849 by 6411 pixels! This is nearly the best full disc mosaic I've ever made. It took many hours to construct and enhance the picture.
The next picture shows a closer view of large sunspot 2546. Good seeing allowed resolution of fine details around the sunspot and on the limb.
Smaller sunspot 2544 had an interesting umbra structure.
Finally, here's a closer view of the brightest prominence on the northeastern limb.
Soon after the nice clear sky on May 16th clouds and rain returned. I'm glad I made the most of such a pleasant observing day.
Sunlight is rare these wet days in Williamsburg. My lawn has never been greener. Although clouds and rain make solar observing impossible, occasionally, the Sun does break through. Late in the day on May 14th an amazing intense rainbow appeared behind my house. Unfortunately, the 6-panel mosaic below failed to capture the very top of the secondary rainbow. I wish I had raised the camera a bit higher! (Click on the image for a larger view.)
The primary rainbow is very bright and shows up nicely against dark background clouds. The higher secondary rainbow is dimmer with colors arrayed in opposite order compared to the primary rainbow. Inside the primary rainbow supernumerary bands are seen, particularly near the top of the arch. View the enlarged image to see the supernumerary bands more clearly. This is the best rainbow I've ever seen!
Two days after the rainbow's appearance the sky finally cleared for several hours. Viewing conditions were nearly ideal with gentle puffs of wind and temperatures in the mid to upper 60's. Seeing was good as I began solar imaging at about 2:00 pm EDT.
The Sun finally showed a few significant features which are displayed in the following 40-panel mosaic made with a 5X Barlow lens. On the left, large sunspot 2546 is located near an accompanying white active area. On the right is smaller sunspot 2544 with its own active area. The large prominence on the upper left limb was particularly bright in the eyepiece. (Click on the image for a larger view.)
The previous image has been reduced to one third of its original size. The full-sized image is a 13.4 MB monster measuring an amazing 6849 by 6411 pixels! This is nearly the best full disc mosaic I've ever made. It took many hours to construct and enhance the picture.
The next picture shows a closer view of large sunspot 2546. Good seeing allowed resolution of fine details around the sunspot and on the limb.
Smaller sunspot 2544 had an interesting umbra structure.
Finally, here's a closer view of the brightest prominence on the northeastern limb.
Soon after the nice clear sky on May 16th clouds and rain returned. I'm glad I made the most of such a pleasant observing day.
Monday, May 16, 2016
Mercury Transit
Battling Clouds
Mercury lines up in front of the Sun every 115.9 days as seen from Earth. During these alignments Mercury is usually above or below the Sun, but, sometimes, Mercury transits directly across the face of the Sun as it did on May 9th. There are 13 or 14 Mercury transits per century compared to only two for Venus. I've been lucky enough to see both Venus transits in 2004 and 2012, but I'm running out of time for transit observing. There will be no Venus transits for the remainder of my life. Although another Mercury transit will happen in 2019, I could be taking a dirt nap before the next transit occurs in 2032! So I was motivated to make extra effort to observe the May 9th transit.
One day before, on May 8th, I checked my equipment to see if everything was working properly. After confirming all was well, in spite of many clouds, I hastily captured one image of sunspot 2542 with nearby filaments. There was no time to take a flat field, so there are subtle vertical bands in this image. The Sun was finally showing remarkable surface features after many bland months. It would have been nice to take more images, but increasing clouds prevented this.
I was excited about transit day because, for once, my observing site was a favored location. The entire transit would be visible for 7.5 hours from 7:12 am to 2:42 pm EDT. All I needed was a clear day! Unfortunately, Williamsburg was in the midst of a long stretch of cloudy rainy weather, and May 9th was destined to be mostly cloudy. Nevertheless, I rose at 5:00 am, set up my equipment at dawn, and was ready to take advantage of any small bit of clear sky by 7:00 am. Temperature near dawn was a chilly 53 degrees, but rose rapidly in the next few hours.
The Sun broke through a cloud gap as the transit began. I hoped to capture Mercury's black disc crossing either a prominence or spicules on the Sun's eastern limb. Hopes were dashed because seeing was absolutely horrible with the Sun close to the horizon barely an hour after sunrise. I could clearly see Mercury crossing spicules very near a small prominence, but the solar limb was swimming around in a blurry mess. The first image below shows Mercury just crossing the limb at 7:15 am. The dreadful lack of detail in this image is caused by extremely unsteady air.
More than an hour later the Sun had risen higher and seeing improved. I patiently waited for an opening in the clouds and captured the next image through haze at 8:41 am. The small prominence in the upper left is where Mercury earlier entered the solar limb. It would have been great to capture Mercury's black disc silhouetted against this prominence, but, as I mentioned before, roiling air made this impossible.
The angular diameter of Mercury's disc was only 12 arc seconds, about one fifth the size of Venus' disc when Venus transits. Twelve arc seconds is 1/300th of a degree! Thirty minutes later I captured one last transit image at 9:21 am showing another prominence lower down on the rim.
Seeing conditions improved as time went on, but clouds thickened. I managed to capture two more images through thin clouds to make the following 2-panel mosaic of sunspot 2542 near the transit action.
Soon the temperature had risen to 77 degrees. By 10:00 am the sky was 90 percent cloudy and getting worse. Satellite images showed no prospect of future clearing, so I decided to quit at 11:45 am. Maybe conditions will be better for the next transit in 2019.
Mercury lines up in front of the Sun every 115.9 days as seen from Earth. During these alignments Mercury is usually above or below the Sun, but, sometimes, Mercury transits directly across the face of the Sun as it did on May 9th. There are 13 or 14 Mercury transits per century compared to only two for Venus. I've been lucky enough to see both Venus transits in 2004 and 2012, but I'm running out of time for transit observing. There will be no Venus transits for the remainder of my life. Although another Mercury transit will happen in 2019, I could be taking a dirt nap before the next transit occurs in 2032! So I was motivated to make extra effort to observe the May 9th transit.
One day before, on May 8th, I checked my equipment to see if everything was working properly. After confirming all was well, in spite of many clouds, I hastily captured one image of sunspot 2542 with nearby filaments. There was no time to take a flat field, so there are subtle vertical bands in this image. The Sun was finally showing remarkable surface features after many bland months. It would have been nice to take more images, but increasing clouds prevented this.
I was excited about transit day because, for once, my observing site was a favored location. The entire transit would be visible for 7.5 hours from 7:12 am to 2:42 pm EDT. All I needed was a clear day! Unfortunately, Williamsburg was in the midst of a long stretch of cloudy rainy weather, and May 9th was destined to be mostly cloudy. Nevertheless, I rose at 5:00 am, set up my equipment at dawn, and was ready to take advantage of any small bit of clear sky by 7:00 am. Temperature near dawn was a chilly 53 degrees, but rose rapidly in the next few hours.
The Sun broke through a cloud gap as the transit began. I hoped to capture Mercury's black disc crossing either a prominence or spicules on the Sun's eastern limb. Hopes were dashed because seeing was absolutely horrible with the Sun close to the horizon barely an hour after sunrise. I could clearly see Mercury crossing spicules very near a small prominence, but the solar limb was swimming around in a blurry mess. The first image below shows Mercury just crossing the limb at 7:15 am. The dreadful lack of detail in this image is caused by extremely unsteady air.
More than an hour later the Sun had risen higher and seeing improved. I patiently waited for an opening in the clouds and captured the next image through haze at 8:41 am. The small prominence in the upper left is where Mercury earlier entered the solar limb. It would have been great to capture Mercury's black disc silhouetted against this prominence, but, as I mentioned before, roiling air made this impossible.
The angular diameter of Mercury's disc was only 12 arc seconds, about one fifth the size of Venus' disc when Venus transits. Twelve arc seconds is 1/300th of a degree! Thirty minutes later I captured one last transit image at 9:21 am showing another prominence lower down on the rim.
Seeing conditions improved as time went on, but clouds thickened. I managed to capture two more images through thin clouds to make the following 2-panel mosaic of sunspot 2542 near the transit action.
Soon the temperature had risen to 77 degrees. By 10:00 am the sky was 90 percent cloudy and getting worse. Satellite images showed no prospect of future clearing, so I decided to quit at 11:45 am. Maybe conditions will be better for the next transit in 2019.
Sunday, May 8, 2016
New ZWO ASI120MC-S Camera
Jupiter In Color
On the evening of April 16th, after a full morning and afternoon of solar imaging, the sky remained completely clear. I returned to my telescope in twilight as the temperature dropped rapidly. Moonlight was bright, but Jupiter was high in the sky and well positioned for imaging. I was anxious to try a new ZWO ASI120MC-S USB 3.0 color camera on Jupiter.
I began capturing Jupiter with a 5X Barlow lens on my 130mm Stellarvue refractor. Seeing was not bad, so I expected better results than I got in the first image below. This image was made by stacking the best 100 frames from a 3,000-frame video. Jupiter's moon, Io, is in the lower right. The image is disappointing because it doesn't show fine detail like swirls in the Jovian cloud bands. Maybe I haven't yet mastered the processing skills to reveal small details. Or, maybe the inherent resolution of my telescope-camera combination isn't sufficient to capture the missing detail. I'll investigate these possibilities in the future.
Next, I tried less magnification. Jupiter is smaller in the next image made with a 3X Barlow lens. In this wider field of view the Jovian moon, Europa, is now visible to the upper left. Fine detail seems better in this image produced by stacking the best 100 frames of a 2,000-frame video.
My final capture of Jupiter was made with a 2X Barlow lens. Now the field of view widens even more to include a third moon, Ganymede, in the far upper left. (The fourth Galilean moon, Callisto, was far out of the field of view to the lower right.)
The image made with the 3X Barlow seems the most pleasing. Maybe it's the closest fit to the imaging system's inherent resolving power. I've ordered a 4X Barlow to see if it better hits the imaging sweet spot.
After completing trial and error experiments with Jupiter, I installed the 5X Barlow with my monochrome ZWO ASI174MM camera and constructed a 30-panel mosaic of the waxing gibbous Moon three days past first quarter. The area near the terminator showed lots of good detail as you can see in the following half-sized image. (Click on the image for a larger view.)
Just a bit of color has been added to the previous image to enhance the view. I'm looking forward to more planetary imaging with the new color camera.
On the evening of April 16th, after a full morning and afternoon of solar imaging, the sky remained completely clear. I returned to my telescope in twilight as the temperature dropped rapidly. Moonlight was bright, but Jupiter was high in the sky and well positioned for imaging. I was anxious to try a new ZWO ASI120MC-S USB 3.0 color camera on Jupiter.
I began capturing Jupiter with a 5X Barlow lens on my 130mm Stellarvue refractor. Seeing was not bad, so I expected better results than I got in the first image below. This image was made by stacking the best 100 frames from a 3,000-frame video. Jupiter's moon, Io, is in the lower right. The image is disappointing because it doesn't show fine detail like swirls in the Jovian cloud bands. Maybe I haven't yet mastered the processing skills to reveal small details. Or, maybe the inherent resolution of my telescope-camera combination isn't sufficient to capture the missing detail. I'll investigate these possibilities in the future.
Next, I tried less magnification. Jupiter is smaller in the next image made with a 3X Barlow lens. In this wider field of view the Jovian moon, Europa, is now visible to the upper left. Fine detail seems better in this image produced by stacking the best 100 frames of a 2,000-frame video.
My final capture of Jupiter was made with a 2X Barlow lens. Now the field of view widens even more to include a third moon, Ganymede, in the far upper left. (The fourth Galilean moon, Callisto, was far out of the field of view to the lower right.)
The image made with the 3X Barlow seems the most pleasing. Maybe it's the closest fit to the imaging system's inherent resolving power. I've ordered a 4X Barlow to see if it better hits the imaging sweet spot.
After completing trial and error experiments with Jupiter, I installed the 5X Barlow with my monochrome ZWO ASI174MM camera and constructed a 30-panel mosaic of the waxing gibbous Moon three days past first quarter. The area near the terminator showed lots of good detail as you can see in the following half-sized image. (Click on the image for a larger view.)
Just a bit of color has been added to the previous image to enhance the view. I'm looking forward to more planetary imaging with the new color camera.
Saturday, April 30, 2016
Solar Granules
Sunspot 2529 - Two Views
During the morning and afternoon of April 16th observing conditions were nearly perfect: clear sky, calm wind, temperature near 60 degrees, and decent seeing. My goal was to image significant sunspot 2529 in both hydrogen alpha and white light.
I began with the hydrogen alpha view. The first image below is an 8-panel mosaic of the Sun's western limb with sunspot 2529 nearby. Some modest prominences adorn the limb. (Click on the images for a larger view.)
The next image is a closer view of the sunspot showing detail in the dark umbra and white active areas near the spot.
Small sunspot 2532 had just emerged on the eastern limb where a spiky prominence can be seen in the next 4-panel mosaic.
Beautiful observing conditions continued into the afternoon, so I mounted my Stellarvue 130mm and tried white light imaging for the third time. Better seeing and better filters improved my results. The next image was my best effort. It was done using a Herschel wedge with a 5X Barlow lens combined with stacked neutral density and uv/ir filters. Detail in the umbra and penumbra is pretty good. Surface granulation is plainly visible, but not as sharp as the umbra detail. This is clearly superior to my previous white light images.
Since the sunspot was getting near the western limb on the right side of the image, the granules there are smeared out. Granule boundaries are sharpest in the center of the solar disc to the left.
I took an image of granules in the center of the disc where no sunspots existed so I could compare my image with an image of the same region taken by the Solar Dynamics Observatory orbiting above the atmosphere. My image is first below followed by the SDO image. I tried to get the image scales roughly equal.
The clarity and sharpness of the satellite image is obviously superior to my image, but I'm getting closer to respectability. My image also contains noticeable distortion in the lower corners. Perhaps I didn't quite get the center of the Sun, or, maybe, it's an optical distortion. I'll keep trying to home in on the correct combination of filters, exposures, and Barlow lenses.
During the morning and afternoon of April 16th observing conditions were nearly perfect: clear sky, calm wind, temperature near 60 degrees, and decent seeing. My goal was to image significant sunspot 2529 in both hydrogen alpha and white light.
I began with the hydrogen alpha view. The first image below is an 8-panel mosaic of the Sun's western limb with sunspot 2529 nearby. Some modest prominences adorn the limb. (Click on the images for a larger view.)
The next image is a closer view of the sunspot showing detail in the dark umbra and white active areas near the spot.
Small sunspot 2532 had just emerged on the eastern limb where a spiky prominence can be seen in the next 4-panel mosaic.
Beautiful observing conditions continued into the afternoon, so I mounted my Stellarvue 130mm and tried white light imaging for the third time. Better seeing and better filters improved my results. The next image was my best effort. It was done using a Herschel wedge with a 5X Barlow lens combined with stacked neutral density and uv/ir filters. Detail in the umbra and penumbra is pretty good. Surface granulation is plainly visible, but not as sharp as the umbra detail. This is clearly superior to my previous white light images.
Since the sunspot was getting near the western limb on the right side of the image, the granules there are smeared out. Granule boundaries are sharpest in the center of the solar disc to the left.
I took an image of granules in the center of the disc where no sunspots existed so I could compare my image with an image of the same region taken by the Solar Dynamics Observatory orbiting above the atmosphere. My image is first below followed by the SDO image. I tried to get the image scales roughly equal.
Friday, April 22, 2016
Magnetic Pinwheel
Worthy Sunspot Finally Appears
Solar activity continues to slide toward sunspot cycle minimum. For months now only modest, solitary sunspots have appeared. Finally, on April 10th, a good-sized sunspot, the largest of 2016 until then, came into good view. I decided to set up my telescope early in spite of the cold 40-degree temperature to take advantage of predicted good seeing. There was little wind, and no clouds, but seeing was not as good as predicted.
The first image below is a 6-panel mosaic showing solitary sunspot 2529 some distance from the eastern limb. The sunspot occupies center stage within a magnetic pinwheel of swirling gases. As you can see, no significant prominences or filaments were present in this quadrant of the Sun.
The sunspot umbra showed interesting structure. (Click on the image for a larger view.)
After capturing images in hydrogen-alpha, I dismounted my Lunt 100mm solar telescope and mounted a 130mm Stellarvue refractor. I hoped to image the sunspot in white light with new filters in place. A 1.8 neutral density filter and a uv/ir filter were installed in the light path. These filters attenuated sunlight enough so I could use suitable exposure times. The first white light image below shows decent detail in the sunspot umbra and penumbra, but surface granulation is washed out.
Many sunspot pictures I see online are processed to make the umbra completely black with no gradation of blackness. The next image is processed this way. It shows the granulation a little more clearly.
In the last two images I noticed how granules are smeared and indistinct in the upper left nearest to the solar limb. Apparently, this loss of detail near the limb happens in even the highest resolution images made by the orbiting Solar Dynamics Observatory, so this effect can't be caused by poor seeing or faulty image processing. The surface to the right of the sunspot shows evidence of granulation, particularly in the second image, but I'm disappointed in the lack of sharp detail. I think a combination of poor seeing and small image scale may be responsible for the blurry appearance .
Solar activity continues to slide toward sunspot cycle minimum. For months now only modest, solitary sunspots have appeared. Finally, on April 10th, a good-sized sunspot, the largest of 2016 until then, came into good view. I decided to set up my telescope early in spite of the cold 40-degree temperature to take advantage of predicted good seeing. There was little wind, and no clouds, but seeing was not as good as predicted.
The first image below is a 6-panel mosaic showing solitary sunspot 2529 some distance from the eastern limb. The sunspot occupies center stage within a magnetic pinwheel of swirling gases. As you can see, no significant prominences or filaments were present in this quadrant of the Sun.
After capturing images in hydrogen-alpha, I dismounted my Lunt 100mm solar telescope and mounted a 130mm Stellarvue refractor. I hoped to image the sunspot in white light with new filters in place. A 1.8 neutral density filter and a uv/ir filter were installed in the light path. These filters attenuated sunlight enough so I could use suitable exposure times. The first white light image below shows decent detail in the sunspot umbra and penumbra, but surface granulation is washed out.
Many sunspot pictures I see online are processed to make the umbra completely black with no gradation of blackness. The next image is processed this way. It shows the granulation a little more clearly.
In the last two images I noticed how granules are smeared and indistinct in the upper left nearest to the solar limb. Apparently, this loss of detail near the limb happens in even the highest resolution images made by the orbiting Solar Dynamics Observatory, so this effect can't be caused by poor seeing or faulty image processing. The surface to the right of the sunspot shows evidence of granulation, particularly in the second image, but I'm disappointed in the lack of sharp detail. I think a combination of poor seeing and small image scale may be responsible for the blurry appearance .
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People say I'm crazy doing what I'm doing
Well they give me all kinds of warnings to save me from ruin
When I say that I'm o.k. well they look at me kind of strange
Surely you're not happy now you no longer play the game
People say I'm lazy dreaming my life away
Well they give me all kinds of advice designed to enlighten me
When I tell them that I'm doing fine watching shadows on the wall
Don't you miss the big time boy you're no longer on the ball
I'm just sitting here watching the wheels go round and round
I really love to watch them roll
No longer riding on the merry-go-round
I just had to let it go
John Lennon






























