Sun

The natural celestial objects nearest to earth are of course those found in our Solar System. Closest to earth is the moon, which gives stunning views, even at the lowest modest magnification. The Sun (see figure 63) is the closest star to earth. Light only takes 8 minutes to arrive here. Using the Lunt LS80THA nice images can be made of the granulation on its surface and of the solar flares (protuberances) around the edge. Using the SkyWatcher Esprit 150ED and a Baader white-light foil-filter images in the full visible spectrum can be taken, reveiling sunspots as if they were projected.
All images on this page have been taken with a monochrome camera and are artificially coloured.


The Sun as imaged on 8 September 2022 @ 10:17 UTC with the Lunt @ f/14 and QHY163 mono.
Figure 1: The Sun as imaged on 8 September 2022 @ 10:17 UTC with the Lunt @ f/14 and QHY163 mono.
On 8 September 2022 the seeing was quite low at InFINNity Deck, so this opportunity was taken to image the Sun. The recording was done in H-alpha, using the Lunt LS80THA @ f/14 (by using a 2x PowerMate), ZWO ADC, and QHYCCD QHY163 mono. A series of 500 frames were collected, 25% of which were stacked using AutoStakkert!3. The result was then processed in PSP (unsharp mask), IMPPG (histogram inversion), and PSP (colourise, vibrancy and crop).
It shows active regions AR3092 to AR3097. The white-light image can be found here.
The original H-alpha image can be found here.


24 August 2022

The Sun as imaged on 24 August 2022 @ 09:21 UTC with the C11 EdgeHD @ f/20 and ZWO ASI174MM.
Figure 2: The Sun as imaged on 24 August 2022 @ 09:21 UTC with the C11 EdgeHD @ f/20 and ZWO ASI174MM.
On 24 August 2022 I again imaged Active Region 3085 of the Sun in white-light using the Celestron C11 XLT EdgeHD, ND5.0 foil-filter, Baader Continuum filter, and ZWO ASI174MM. A recording of 500 frames was made around 09:21UTC, 18 percent of which were stacked using AutoStakkert!3 to adjacent result. Processing was done using PSP (unsharp mask, colourise, crop, vibrancy).
The original can be found here.


17 July 2022

The Sun as imaged on 17 July 2022 @ 08:49 UTC with the C11 EdgeHD @ f/20 and ZWO ASI174MM.
Figure 3: The Sun as imaged on 17 July 2022 @ 08:49 UTC with the C11 EdgeHD @ f/20 and ZWO ASI174MM.
On 17 July 2022 I spent a few hours in the observatory looking at the Sun. After the daily sketch I decided to image the Sun in white-light using the Celestron C11 XLT EdgeHD, ND5.0 foil-filter, Baader Continuum filter, and ZWO ASI174MM. A recording of 500 frames was made around 08:49UTC, 10 of which were stacked using AutoStakkert!3 to adjacent result. Processing was done using PSP (unsharp mask), IMPPG (Lucy Richardson deconvolution and further unsharp mask), and PSP again (colourise, crop, vibrancy).
The original can be found here.


The Sun as imaged on 17 July 2022 @ 08:49 UTC with the Lunt @ f/14 and QHY163 mono.
Figure 4: The Sun as imaged on 17 July 2022 @ 08:49 UTC with the Lunt @ f/14 and QHY163 mono.
Shortly after imaging the Sun with the C11, another attempt was done at around 08:49 UTC, now in H-alpha, using the Lunt LS80THA @ f/14, ZWO ADC, and QHYCCD QHY163 mono. A series of 500 frames were collected, 25 of which were stacked using AutoStakkert!3. The result was then processed in PSP (unsharp mask), IMPPG (histogram inversion), and PSP (colourise, vibrancy and crop).
The original can be found here.


2 July 2022

The Sun as imaged on 2 July 2022 @ 08:37 UTC with the Lunt @ f/14 and QHY163 mono.
Figure 5: The Sun as imaged on 2 July 2022 @ 08:37 UTC with the Lunt @ f/14 and QHY163 mono.
The day before the Dutch and Belgium Sun Watching Day, the Sun was imaged around 08:37UTC using the Lunt LS80THA, Televue 2x PowerMate, ZWO ADC and QHY163 mono. The Solar Scintillation Seeing Monitor (SSSM) indicated a seeing of 2-3 arc-seconds. A total of 500 frames was captured, 20% of which were stacked using AutoStakkert!3.
Processing done with PSP (Unsharp Mask), IMPPG (Lucy-Richardson Deconvolution, histogram inversion), and PSP (colourise and crop).
The original can be found here.


27 June 2022

The Sun as imaged on 27 June 2022 @ 17:25 UTC with the Lunt @ f/14 and QHY163 mono.
Figure 6: The Sun as imaged on 27 June 2022 @ 17:25 UTC with the Lunt @ f/14 and QHY163 mono.
On 27 June new activity is visible on the southwestern limb of the Sun. This image was taken with the Lunt LS80THA, QHY163 camera and Televue 2x PowerMate at 17:25 UTC. Capture was done with FireCapture, while AutoStakkert!3 was used to stack 100 out of the 500 frames. Post-processing was done in IMPPG and PSP.
The original can be found here.


23 June 2022

The Sun as imaged on 23 June 2022 @ 08:06 UTC with the Lunt @ f/14 and QHY163 mono.
Figure 7: The Sun as imaged on 23 June 2022 @ 08:06 UTC with the Lunt @ f/14 and QHY163 mono.
On 23 June one of the protuberances approached the limb of the Sun. Being rather bright this gave an impressive view through the eyepiece of the Lunt LS80THA. Immediately the QHY163 camera and Televue 2x PowerMate was attached and adjacent image was taken at 08:06 UTC. Capture was done with FireCapture, while AutoStakkert!3 was used to stack 50 out of the 500 frames. Post-processing was done in IMPPG and PSP.
The original can be found here.


Detail of the Sun as imaged on 23 June 2022 @ 08:14 UTC with the Lunt @ f/28 and QHY163 mono.
Figure 8: Detail of the Sun as imaged on 23 June 2022 @ 08:14 UTC with the Lunt @ f/28 and QHY163 mono.
Using a Televue 4x PowerMate the Lunt was changed to a f/28 scope. Although the seeing was mediocre (4 arc-seconds) and the scope has a resolving power of only 1.7", the result is still reasonable good despite sampling at 0.35" per pixel.
The image was taken at 08:14UTC. Again 50 out of 500 frames stacked.
The original can be found here.


Detail of the Sun as imaged on 23 June 2022 @ 08:14 UTC with the Lunt @ f/28 and QHY163 mono.
Figure 9: Detail of the Sun as imaged on 23 June 2022 @ 08:14 UTC with the Lunt @ f/28 and QHY163 mono.
The same frames were also processed in non-inverted way.
The original can be found here.


Animation of the Sun as imaged between 9 and 23 June 2022.
Figure 10: Animation of the Sun as imaged between 9 and 23 June 2022.
Today was the end of a period of 15 consecutive days in which I managed to image the Sun in white light using the SkyWatcher Esprit 150ED, a Baader ND5.0 foil filter and ZWO ASI1600MM Pro Cool.
Using EzGif.com I created this animation that spans the period 9 - 23 June 2022. All frames processed with AutoStakkert!3 (10% of 230 frames) and PSP (colourise and crop).


21 June 2022

The Sun as imaged on 21 June 2022 @ 09:29 UTC with the Lunt @ f/14 and QHY163 mono.
Figure 11: The Sun as imaged on 21 June 2022 @ 09:29 UTC with the Lunt @ f/14 and QHY163 mono.
At the longest day of 2022 the sky started out fully overcast, but during the morning it cleared, although leaving us with some thin stratus.
The Sun was imaged using the Lunt LS80THA, Televue 2x PowerMate, ZWO ADC and QHY163 mono. A Solar Scintillation Seeing Monitor (SSSM) was used to trigger the capture as seeing varied a lot and mainly was mediocre to quite poor (5-8"). At one moment it dropped well below 4", triggering the capture of adjacent image.
Processing done with PSP (Unsharp Mask), IMPPG (Lucy-Richardson Deconvolution, histogram inversion), and PSP (colourise and crop).
The original can be found here.


17 June 2022

Active regions AR3030/AR3032 as imaged with the C11 EdgeHD on 17 June @ 09:10UTC.
Figure 12: Active regions AR3030/AR3032 as imaged with the C11 EdgeHD on 17 June @ 09:10UTC.
Today seeing was incredibly low, just under 2", reason enough to revisit the active regions AR3030 and AR3032 with the C11 EdgeHD, 2x PowerMate, ND5.0 foil filter, Baader Continuum filter and ZWO ASI174MM. Using again of 250 resulted in exposure times of 8.3ms. In 15 seconds 774 frames were captured, 10 percent of which were stacked with AutoStakkert!3. Noise reduction was done in Topaz (Low Light), after which Unsharp Mask was applied in PSP and Lucy-Richardson deconvolution in IMPPG. Finally the image was given a colour in PSP, cropped to the current size and overlaid with an image of the Earth to scale.

The full resolution original can be found here.


Active regions AR3031/AR3037 as imaged with the C11 EdgeHD on 17 June @ 09:11UTC.
Figure 13: Active regions AR3031/AR3037 as imaged with the C11 EdgeHD on 17 June @ 09:11UTC.
A minute later active regions AR3031 and AR3037 where imaged under the same circumstances. Again a gain of 250 was applied, resulting in 8.3ms exposure times. In 15 second 773 frames were captured, of which 10 percent were stacked. All processing was the same as with active regions AR3030/AR3032 above.

The full resolution original can be found here.


16 June 2022

The Sun as imaged on 16 June 2022 @ 08:14 UTC with the Lunt @ f/14 and QHY163 mono.
Figure 14: The Sun as imaged on 16 June 2022 @ 08:14 UTC with the Lunt @ f/14 and QHY163 mono.
On 16 June 2022 there still was a significant amount of sunspots visible on the Sun. Using the GTT60 I counted 34 of them. Using the Lunt LS80THA and QHY163 mono adjacent image was taken at around 08:14UTC. post-processing done in PSP (Unsharp Mask), IMPPG (histogram inversion and Lucy-Richardson deconvolution), and PSP (colourize, mirror and crop).

The full resolution original can be found here.

At 07:48UTC I had already imaged the Sun in white-light using the SkyWatcher Esprit 150ED, ND5.0 foil filter and ZWO ASI1600MM Pro Cool camera. The full resolution original of that image can be found here.


Active regions AR3030/AR3032 as imaged with the C11 EdgeHD on 16 June @ 07:58UTC.
Figure 15: Active regions AR3030/AR3032 as imaged with the C11 EdgeHD on 16 June @ 07:58UTC.
Using the Celestron C11 XLT EdgeHD active regions AR3030/AR3032 where imaged around 07:58UTC at f/20 with a ZWO ASI174MM, ND5.0 foil and Baader Continuum filter.

The full resolution original can be found here.


Active regions AR3031/AR3037 as imaged with the C11 EdgeHD on 16 June @ 08:03UTC.
Figure 16: Active regions AR3031/AR3037 as imaged with the C11 EdgeHD on 16 June @ 08:03UTC.
Using the Celestron C11 XLT EdgeHD active regions AR3031/AR3037 where imaged around 08:03UTC at f/20 with a ZWO ASI174MM, ND5.0 foil and Baader Continuum filter.

The full resolution original can be found here.


15 June 2022

The Sun as imaged on 15 June 2022 @ 07:58 UTC with the Esprit 150ED and ZWO ASI1600MM Pro Cool.
Figure 17: The Sun as imaged on 15 June 2022 @ 07:58 UTC with the Esprit 150ED and ZWO ASI1600MM Pro Cool.
On 15 June 2022 there was a significant amount of sunspots visible on the Sun. Using the GTT60 I counted 38 of them. The image I took straight afterwards with the SkyWatcher Esprit 150ED, ND5.0 foil filter and ZWO ASI1600MM Pro Cool camera shows there were quite a few more than that.
Recording of 30 seconds at unity gain in which 230 frames were captured. Processed in AutoStakkert!3 with sharpening (30% blend). Postprocessing in PSP, adding colour and creating this crop.

The full resolution original can be found here.


10 June 2022

The Sun as imaged on 10 May 2022 @ 10:13 UTC showing AR3029, a new set of sunspots and an aeroplane.
Figure 18: The Sun as imaged on 10 May 2022 @ 10:13 UTC showing AR3029, a new set of sunspots and an aeroplane.
On 10 June 2022 I was imaging the Sun with the SkyWatcher Esprit 150ED as part of my daily sunspot count with the GTT60 when halfway an aeroplane 'ruined' the shot. Using AutoStakkert!3 (export frames), PIPP (centring and resizing frames to 900×900px), PSP (batch sharpen and colourize), and EzGif.com (animation) I created this animation.


9 June 2022

The Sun as imaged on 9 May 2022 @ 08:04 UTC with the Lunt @ f/14 and QHY163 mono.
Figure 19: The Sun as imaged on 9 May 2022 @ 08:04 UTC with the Lunt @ f/14 and QHY163 mono.
On 9 June we had clear skies and reasonable to good seeing (2.5 - 3"), so time to experiment with the QHY163 again, but now in the morning. Being pointed at the eastern hemisphere the deformation of the scope and imaging train differs from the previous image and the question was whether or not this would affect the even illumination of the image. As it turned out only a minor tweak of the ZWO ADC was required to bring the hotspot to the centre of the solar disc.
Imaging was triggered by the Solar Scintillation Seeing Monitor and done using the QHY163 Mono and TeleVue 2x PowerMate through the Lunt LS80THA. A SER-movie of 250 frames was shot, 10% of which was stacked in AutoStakkert!3. Post-processing in PSP (Unsharp Mask), IMPPG (inversion and LRD) and PSP again (colourise and crop).
The original can be found here.


28 May 2022

The Sun as imaged on 28 May 2022 at 15:48 UTC with the Lunt LS80THA @ f/14 and QHY163.
Figure 20: The Sun as imaged on 28 May 2022 at 15:48 UTC with the Lunt LS80THA @ f/14 and QHY163.
Today I have been experimenting to get the Sun into the sweet-spot of the Lunt. It appeared that the sweet-spot is not projected on the centre of the imaging-chip, but some 1.34 millimetres to the right and 0.69 millimetres upwards. As I am using an ADC to get rid of the Newton-rings, I tried to change the ADC orientation and settings to shift the Sun and sweet-spot to the centre of the chip, which indeed I managed to do with an evenly illuminated solar image as result.
Recording made around 15:48UTC, 20 frames of a total of 500 frames stacked. Postprocessing in PSP (unsharp-mask), IMPPG (inversion and Lucy-Richardson deconvolution), and PSP again (colourise, vibrancy, mirror).
The original can be found here.


14 May 2022

The Sun as imaged on 14 May 2022 @ 17:12 UTC with the Lunt @ f/14, showing a large prominence.
Figure 21: The Sun as imaged on 14 May 2022 @ 17:12 UTC with the Lunt @ f/14, showing a large prominence.
Today there was, in addition to several active regions, a massive prominence visible at the Sun. Image taken with the Lunt LS80THA in combination with TeleVue 2x PowerMate and QHY163 mono camera. In 60s 946 frames were captured, 15% of which were stacked using AutoStakkert!3. Post-processing in PSP, IMPPG and again PSP.
The original can be found here.


10 May 2022

The Sun as imaged on 10 May 2022 at 17:08 UTC with the Lunt LS80THA @ f/14 and QHY163.
Figure 22: The Sun as imaged on 10 May 2022 at 17:08 UTC with the Lunt LS80THA @ f/14 and QHY163.
The past few days I have been experimenting with a QHY163 that I added to the observatory half a year ago. The camera was added to serve as an alternative for the ZWO ASI1600MM Pro Cool when that camera goes behind the SkyWatcher Esprit 80ED for deep-sky imaging. In that way I could still make full-disc images in white light with the Esprit 150ED.
Last week I realised that, using a 2x PowerMate, the QHY163 would still produce full-disc images with the Lunt, but at three times the resolution of the ZWO ASI174MM that I used for this up to now. After a few tests I found a way to deal with Newton rings and to get rid of the chessboard pattern.
Today seeing was quite good with values between 2.5" and 3.0". The recording was made at around 17:08 UTC and took 15 seconds in which 353 frames were captured at an exposure time of 1.243ms. Processing was done with AutoStakkert!3 in which 25% of the frames were stacked. Post-processing was done in PSP (200% resize, Unsharp Mask [40, 40, 0], 50% resize), IMPPG (histogram inversion and Lucy-Richardson deconvolution @ 1.7 and 50 iterations) and again PSP (colourise, sharpen more, vertical flip, adding room to canvas size).
The original can be found here.


5 May 2022

The Sun as imaged on 5 May 2022 @ 12:50 UTC with the C11 EdgeHD @ f/20, showing AR3004.
Figure 23: The Sun as imaged on 5 May 2022 @ 12:50 UTC with the C11 EdgeHD @ f/20, showing AR3004.
On 5 May 2022 seeing was mediocre, but with very short periods of improvements, even that short that they remained undetected by the scintillation seeing monitor, but not short enough to become unnoticed. Using the Celestron C11 XLT EdgeHD, Baader ND5.0 foil, Baader Continuum filter and ZWO ASI174MM adjacent image was taken. The image is the result of a 15 seconds movie in which 775 frames were captured, 10 frames of which were stacked with AutoStakkert!3, sharpened with Topaz Denoise and further processed in PSP (another sharpening and colourize).
Click here for the full version.


4 May 2022

The Sun as imaged on 4 May 2022 @ 08:06 UTC with the SkyWatcher Esprit 150ED at f/7.
Figure 24: The Sun as imaged on 4 May 2022 @ 08:06 UTC with the SkyWatcher Esprit 150ED at f/7.
The numbering of active regions has passed 13000! Today seeing was too poor to shoot detailed images, but this full-disc image of 08:06UTC of the Sun shows AR3004 at the centre of the Sun. Below it AR3001 can be seen, while the region to the right is AR2999. The one at the left is AR3006.
Image taken with the SkyWatcher Esprit 150ED and ZWO ASI1600MM Pro Cool. Post processing of 10% of 230 frames done with sharpening and 30% blend in AutoStakkert!3.
The original image can be found here.


23 April 2022

The Sun as imaged on 23 April 2022 @ 08:44 UTC with the C11 EdgeHD at f/20.
Figure 25: The Sun as imaged on 23 April 2022 @ 08:44 UTC with the C11 EdgeHD at f/20.
In the week of 23 April seeing finally was good enough to do some imaging with the C11 EdgeHD. For that it is equipped with a Baader ND5.0 foil filter and Baader Continuum filter. Using a TeleVue 2x PowerMate Barlow the focal length was increased to 5588mm.
The image shows active regions AR2993 and AR2994 as they were at around 08:44 UTC. Recording was done using the ZWO ASI174MM. In 15 seconds 773 frames were captured, 10 frames of which were stacked using AutoStakkert!3. Postprocessing done in IMPPG and PSP.
The inset at the lower right shows the Earth to scale.
The full resolution image can be found here.


The Sun as imaged on 23 April 2022 @ 08:36 UTC with the SkyWatcher Esprit 150ED at f/7.
Figure 26: The Sun as imaged on 23 April 2022 @ 08:36 UTC with the SkyWatcher Esprit 150ED at f/7.
Using the SkyWatcher Esprit 150ED, Baader ND5.0 foil and the ZWO ASI1600MM Pro Cool camera, this full disc image of the Sun with AR2991 and AR2993 t/m AR2996 was taken around 08:36 UTC on 23 April 2022.
In 30 seconds 230 frames were captured, 10% of which were stacked with AutoStakkert!3 with sharpening and 30% raw blend enabled. Post-processing done in PSP.
The full resolution image can be found here.


16 April 2022

The Sun as imaged on 16 April 2022 @ 10:35 UTC with the Lunt LS80THA at native focal length.
Figure 27: The Sun as imaged on 16 April 2022 @ 10:35 UTC with the Lunt LS80THA at native focal length.
Slowly but surely the Sun is showing more and more activity. This image was taken on 16 April 2022 at 10:35UTC using the Lunt LS80THA @ f/7. At 10 o'clock a faint but massive protuberance, more than 7 times the Earth's diameter, can be seen.
The image is the result of 30 seconds imaging in which 1662 frames were captured, 10% of which were stacked using AutoStakkert!3. Post-processing done in IMPPG and PSP.
The full resolution image can be found here.


3 March 2022

The Sun as imaged on 3 March 2022 @ 11:01 UTC with the Lunt LS80THA at native focal length.
Figure 28: The Sun as imaged on 3 March 2022 @ 11:01 UTC with the Lunt LS80THA at native focal length.
After a three month delay due to maintenance on the mount the Sun was finally imaged again in H-alpha using the Lunt LS80THA @f/7 on 3 March 2022 at 11:01 UTC. In 30 seconds 2061 frames were captured, 25% of which were stacked in AutoStakkert! to produce this image. Histogram inversion and stretch was done in IMPPG, colourizing in PSP.
The full resolution image can be found here.


28 October 2021

The Sun with AR2886, AR2887, AR2889 - AR2891 as imaged on 28 October 2021 with the Esprit 150ED.
Figure 29: The Sun with AR2886, AR2887, AR2889 - AR2891 as imaged on 28 October 2021 with the Esprit 150ED.
On 28 October 2021 seeing was excellent and a lot of features were visible on the Sun. Imaging was done with three scopes in four configurations. Adjacent image shows the Sun in white light and was taken with the SkyWatcher Esprit 150ED with Baader ND5.0 foil filter and ZWO ASI1600MM Pro Cool. It shows active regions AR2886, AR2887, AR2889, AR2890 and AR2891.


The Sun as imaged on 28 October 2021 with the Lunt LS80THA at native focal length.
Figure 30: The Sun as imaged on 28 October 2021 with the Lunt LS80THA at native focal length.
Using the Lunt LS80THA at native focal length (f/7) adjacent image was taken showing quite a few protuberances and more surface activity than in white light. The full resolution image can be found here.


A close-up of active region AR2887 as imaged on 28 October at around 10:53UTC.
Figure 31: A close-up of active region AR2887 as imaged on 28 October at around 10:53UTC.
Using a 4x PowerMate this close-up of AR2887 was taken with the Lunt. The full resolution image can be found here.


A close-up of active region AR2887 as imaged on 28 October at around 10:22UTC in white light.
Figure 32: A close-up of active region AR2887 as imaged on 28 October at around 10:22UTC in white light.
Using teh Celestron C11 EdgeHD, Baader ND5.0 foil and Continuum filters and the ZWO ASI174MM adjacent image of active region AR2887 in white light was taken. The full resolution image can be found here.


9 September 2021

Detail of the sun as imaged on 9 September 2021 around 09:04 UTC.
Figure 33: Detail of the sun as imaged on 9 September 2021 around 09:04 UTC.
On 9 September 2021 quite a few active regions could be seen with a large number of sunspots. Using the SkyWatcher Esprit 150ED, the Celestron C11 XLT EdgeHD and Lunt LS80THA I made several images. Seeing was exceptionally good, resulting in my most detailed solar images so far.
Adjacent figure shows the full disc image taken with the SkyWatcher Esprit 150ED and ND5.0 foil filter. The full resolution image can be found here.


Detail of the sun as imaged on 9 September 2021 around 09:21 UTC using the C11 EdgeHD @ f/20.
Figure 34: Detail of the sun as imaged on 9 September 2021 around 09:21 UTC using the C11 EdgeHD @ f/20.
Using the Celestron C11 EdgeHD, a ND5.0 foil filter and Baader Continuum filter adjacent image was taken at 09:21 UTC. The image shows granulation and even structure inside the umbras of the active regions, which are AR2866 and AR2868.
The full resolution image can be found here.


Detail of the sun as imaged on 9 September 2021 around 09:56 UTC using the Lunt LS80THA @ f/7.
Figure 35: Detail of the sun as imaged on 9 September 2021 around 09:56 UTC using the Lunt LS80THA @ f/7.
In H-alpha the Sun looked great as well, even though seeing had dropped to about 4". Adjacent image was taken with the Lunt LS80THA @ f/7, using the ZWO ASI174MM camera.
The full resolution image can be found here.


Detail of the sun as imaged on 9 September 2021 around 10:03 UTC using the Lunt LS80THA @ f/28.
Figure 36: Detail of the sun as imaged on 9 September 2021 around 10:03 UTC using the Lunt LS80THA @ f/28.
Adjacent image was taken with the Lunt LS80THA @ f/28 using a TeleVue 4x PowerMate and ZWO ASI174MM camera.
The image shows active regions AR2866, AR2868 and AR2869.
The full resolution image can be found here.


28 August 2021

The Sun with AR2860 as imaged on 28 August 2021 with the Esprit 150ED.
Figure 37: The Sun with AR2860 as imaged on 28 August 2021 with the Esprit 150ED.
A few days before 28 August 2021 a large active region became visible on the Sun's surface. On the 28th I imaged the Sun with both the SkyWatcher Esprit 150ED and the Celestron C11 XLT EdgeHD. Adjacent image was taken with the Esprit in combination with a Baader ND5.0 foil filter and ZWO ASI1600MM Pro Cool camera.


Active region AR2860 in close-up with the C11 @f/20.
Figure 38: Active region AR2860 in close-up with the C11 @f/20.
The largest group, AR2860, was also imaged with the Celestron C11 XLT EdgeHD, a Baader ND5.0 filter, Baader Continuum filter and ZWO ASI174MM.
The full resolution image can be found here


4 July 2021

The Sun in white light as seen on 4 July 2021 at 08:31UTC.
Figure 39: The Sun in white light as seen on 4 July 2021 at 08:31UTC.
On 4 July 2021 the third edition of the national Sun Watching Day took place and again InFINNity Deck was open to the public. Between 10:30am and 8pm 21 people (22 if the youngest visitor of 6 months old is included) visited the observatory. I was assisted by astro-friends Caspar, Rob and Roman. The latter two of them brought two mounts with respectively an 80mm APO with DayStar Quark and a 100mm ED with Herschel wedge. Their mounts were set-up in the garden between the sundials. In addition a slide-show with the best solar images of last year (most of which are shown on this page) was running in the garage. Adjacent image was taken at 08:31UTC, at the time the first visitors arrived.


16 June 2021

Solarspot AR2833 as imaged on 16 June 2021 with the C11 @ f/20.
Figure 40: Solarspot AR2833 as imaged on 16 June 2021 with the C11 @ f/20.
On 16 June 2021 I imaged AR2833 using the Celestron C11 XLT EdgeHD. This region was also visible two weeks earlier and at the time known as AR2824.
Imaging done with the ZWO ASI174 and TeleVue 2x PowerMate, processing in AS!3 and PSP, animation in EZGif.com.
The full resolution animation can be found here


AR2833 as imaged on 16 June 2021 using SkyWatcher Esprit 150ED.
Figure 41: AR2833 as imaged on 16 June 2021 using SkyWatcher Esprit 150ED.
That same day I also used the SkyWatcher Esprit 150ED to image AR2833, which produced a very similar image as on 20 May when the spot was still named AR2824.


10 June 2021

The partial solar eclipse as seen from InFINNity Deck on 10 June 2021.
Figure 42: The partial solar eclipse as seen from InFINNity Deck on 10 June 2021.
On 10 July 2021 a partial solar eclipse was visible from InFINNity Deck. That day all four telescopes were used to observe the Sun. The GTT60 was used to project the solar disk onto paper, the Celestron C11 XLT EdgeHD for visual observations using a Baader ND5.0 foil and a polarizing filter in between the star diagonal and 41mm TeleVue Panoptic eyepiece.
Adjacent image was the result of a series of images taken with the SkyWatcher Esprit 150ED through a Baader ND5.0 foil filter, using the ZWO ASI1600MM Pro Cool camera. In total 37 recordings were made of 20 seconds (145 frames per recording). These were processed in PSP and downsized to 1338x1290 pixels in order to create the animation from it.
On the surface several sunspots can be seen. Positioning your mouse next to one of them allows to see the rotation of the sun during this 3 hours time-lapse. The first frame was shot at 08:07UTC, the second at 09:01UTC. All following frames were taken from that moment on at an average 5 minutes interval.
Along the limb of the Moon clearly some mountainous terrain can be observed.
The full resolution version can be found here.


The partial solar eclipse in H-alpha (inverted processing) as seen on 10 June 2021.
Figure 43: The partial solar eclipse in H-alpha (inverted processing) as seen on 10 June 2021.
The fourth scope used to catch the partial solar eclipse of 10 June 2021 was the Lunt LS80THA, which recorded the Sun in H-alpha mode. Again 37 recordings were made to create adjacent image, but now of 30 seconds in length (2200 frames per recording). These were processed in IMPPG and PSP and are shown here at their original scale.
On the surface several sunspots can be seen. Positioning your mouse next to one of them allows to see the rotation of the sun during this 3 hours time-lapse. The first frame was shot at 08:24UTC, the second at 09:00UTC. All following frames were taken from that moment on at an average 5 minutes interval.
Two additional recordings were made around the time of first and second contact. From these the first contact was found to be at 09:18:11UTC (theoretically, according to Stellarium for our location, this would have been 09:17:55UTC) with an uncertainty due to undulation of 1 second. The second contact was found to be at around 11:31:45UTC (theoretically 11:31:26UTC) with an uncertainty of 3 seconds.
The full resolution version can be found here.


The partial solar eclipse in H-alpha (normal processing) as seen on 10 June 2021.
Figure 44: The partial solar eclipse in H-alpha (normal processing) as seen on 10 June 2021.
That same dataset can also be processed in a non-inverted fashion to produce adjacent image.
The full resolution version can be found here.


The partial solar eclipse as projected using the GTT60.
Figure 45: The partial solar eclipse as projected using the GTT60.
Using the GTT60 I projected the Sun to see the partial eclipse and accompanying sunspots.


7 June 2021

Detail of the sun as imaged on 7 June around 08:08 UTC in white-light with a C11.
Figure 46: Detail of the sun as imaged on 7 June around 08:08 UTC in white-light with a C11.
Using the Celestron C11 XLT EdgeHD in combination with Baader ND5.0 foil filter and a TeleVue 4x PowerMate adjacent detail was made in white-light.


2 June 2021

The Sun in H-alpha on 2 June 2021, showing sunspots AR2827.
Figure 47: The Sun in H-alpha on 2 June 2021, showing sunspots AR2827.
Today AR2827 is still active and a few nice prominences are visible along the limb. Image taken with the Lunt LS80THA and ZWO ASI174MM at 09:51UTC.
Post-processing in PSP, the full image can be found here.


1 June 2021

Sunspot AR2827 imaged on 1 June 2021 using the C11 EdgeHD and Baader ND5.0 foil.
Figure 48: Sunspot AR2827 imaged on 1 June 2021 using the C11 EdgeHD and Baader ND5.0 foil.
On 1 June 2021 I gave sunspot AR2827 another try, again using the Celestron C11 XLT EdgeHD with Baader ND5.0 filter foil and the green filter from the filter wheel. The rest of the optical train consisted of a TeleVue 4x PowerMate (so f/40) and ZWO ASI174MM. A gain of 300 was used, resulting in exposure time of 2.4ms. In 30 seconds 1136 frames were captured, which were processed in AS3! using a stack length of 20 and some 2750 APs (AP-size was set to 48 and rendered full-frame).
Post-processing was re-done on 25 July in PSP (Unsharp Mask), IMPPG (LR-deconvolution), and PSP again (further sharpening and colour), the full image can be found here.


The full disc image of the Sun taken on 1 June 2021.
Figure 49: The full disc image of the Sun taken on 1 June 2021.
To give an idea of scale, sunspot AR2827 from above C11-image is shown here in a full-disc image taken with the SkyWatcher Esprit 150ED. For imaging a ZWO ASi1600MM Pro Cool was used, as well in combination with a ND5.0 foil and luminance filter.
The full image can be found here.


31 May 2021

Sunspot AR2827 imaged on 21 May 2021 using the C11 EdgeHD and Baader ND5.0 foil.
Figure 50: Sunspot AR2827 imaged on 21 May 2021 using the C11 EdgeHD and Baader ND5.0 foil.
Last week I got myself a decent sheet of Baader ND5.0 solar filter foil (49x50cm). I had read on various fora that the ND5.0 foil was not suitable for solar imaging as it reduced exposure times too much, but then the main purpose for the filter was for visual observing. Of course I could not resist using it for imaging as well, just to see how far I could get with my first attempt.
So this morning I gave it a try at 7:30am UTC with the Sun just peeking over the tree-tops into the observatory and showing sunspot AR2827. The imaging scope is my Celestron C11 XLT EdgeHD. I used a green filter (have no continuum filter yet), a TeleVue 4x PowerMate and ZWO ASI174MM.
Setting the camera to a gain of 300 resulted in 3.2ms exposures and a 66FPS frame-rate. Seeing was the greatest issue, but out of 10 SER-movies of 30s and 2000 frames each, 10 frames of one of them were good enough to stack. The Earth was added to scale.
The full resolution image can be found here.


20 May 2021

Sunspot AR2824 as imaged on 20 May 2021 09:03UTC with the SkyWatcher Esprit 150ED.
Figure 51: Sunspot AR2824 as imaged on 20 May 2021 09:03UTC with the SkyWatcher Esprit 150ED.
On 20 May 2021 sunspot AR2824 showed up very nice. I had been seeing it during the previous two days using the GTT60 and the SkyWatcher Esprit 150ED, but today I decided to image it with the Lunt LS80THA as well. Adjacent image was taken on 09:03UTC with the Esprit 150ED. The image is the result of 30s capturing with FireCapture, which resulted in 237 frames, 25% of which were stacked with AS3!. Post-processing done with IMPPG and PSP.


Sunspot AR2824 as imaged on 20 May 2021 09:17UTC with the Lunt LS80THA.
Figure 52: Sunspot AR2824 as imaged on 20 May 2021 09:17UTC with the Lunt LS80THA.
A few minutes later, on 09:17UTC, the adjacent H-alpha image was taken with the Lunt LS80THA. Again 30s exposures, now resulting in 1853 frames, 25% of which were stacked.


Close-up of sunspot AR2824 as imaged on 20 May 2021 10:01UTC with the Lunt LS80THA.
Figure 53: Close-up of sunspot AR2824 as imaged on 20 May 2021 10:01UTC with the Lunt LS80THA.
Finally a close-up was taken at 10:01UTC with the Lunt LS80THA, but now with a TeleVue 4x PowerMate in between the scope and ZWO ASI174MM camera. Once again 30s exposure, resulting in 1001 frames, 15% of which were stacked. Postprocessing with IMPPG and PSP.


10 May 2021

The sun as imaged on 10 May 2021 around 12:11 UTC.
Figure 54: The sun as imaged on 10 May 2021 around 12:11 UTC.
On 10 May 2021 two active regions could be seen: AR2822 and AR2823. In addition several prominences could be seen. Adjacent image was taken with the Lunt LS80THA in combination met the ZWO ASI174MM.


The sun as imaged on 10 May 2021 around 12:11 UTC in white-light.
Figure 55: The sun as imaged on 10 May 2021 around 12:11 UTC in white-light.
That same day I also imaged the Sun using the SkyWatcher Esprit 150ED and ZWO ASI1600MM Pro Cool.


Detail of the sun as imaged on 10 May 2021 around 12:11 UTC in H-alpha.
Figure 56: Detail of the sun as imaged on 10 May 2021 around 12:11 UTC in H-alpha.


Detail of the sun as imaged on 10 May 2021 around 12:11 UTC in H-alpha.
Figure 57: Detail of the sun as imaged on 10 May 2021 around 12:11 UTC in H-alpha.


Detail of the sun as imaged on 10 May 2021 around 12:11 UTC in H-alpha.
Figure 58: Detail of the sun as imaged on 10 May 2021 around 12:11 UTC in H-alpha.


16 - 27 April 2021

A 12 day long animation as imaged in April 2021, showing the rotation of the Sun with sunspots.
Figure 59: A 12 day long animation as imaged in April 2021, showing the rotation of the Sun with sunspots.
Between 16 and 27 April 2021 I managed to daily image the Sun in white-light using the SkyWatcher Esprit 150ED. From these 12 frames the adjacent animation was created.
The same animation at 900px x 900px resolution can be found here.


27 April 2021

The Sun on 27 April 2021 at 08:28UTC.
Figure 60: The Sun on 27 April 2021 at 08:28UTC.
On 27 April 2021 I took adjacent image of the Sun in H-alpha using the Lunt LS80THA and ZWO ASI174MM monochrome camera.


Detail of the sun as imaged on 27 April around 08:34 UTC in H-alpha.
Figure 61: Detail of the sun as imaged on 27 April around 08:34 UTC in H-alpha.
Using the same scope, but now in combination with a TeleVue 4x PowerMate I made adjacent image. In 30 seconds 3505 frames were captured, 5% of which were stacked to produce this image. Post-processing in PSP.


26 April 2021

The Sun on 26 April 2021 at 09:13UTC.
Figure 62: The Sun on 26 April 2021 at 09:13UTC.
On 26 April 2021 I took adjacent image of the Sun in H-alpha using the Lunt LS80THA and ZWO ASI174MM monochrome camera.


5 March 2021

Half an hour animation of a protuberance on 5 March 2021.
Figure 63: Half an hour animation of a protuberance on 5 March 2021.
On 5 March 2021 a nice protuberance could be seen at the limb of the sun. Using the Lunt LS80THA with the TeleVue 4x PowerMate and ZWO ASI174MM nine SER-videos of 30 seconds were captured. Processing was done in AS3!, IMPPG and PSP. Finally the resulting images were combined using EZGIF-maker.
The image shown here as figure 63 is a cropped and resized version of the original, which can be found here.


11 April 2021

The Sun showing a nice large protuberance on 11 April 2021.
Figure 64: The Sun showing a nice large protuberance on 11 April 2021.
On 11 April 2021 the Sun was quite active, showing a large prominence at the western limb. Image was taken with the Lunt LS80THA solar-telescope and ZWO ASI174MM camera.


A close-up of the large protuberance of 11 April 2021.
Figure 65: A close-up of the large protuberance of 11 April 2021.
A close-up of the large protuberance of 11 April 2021.


26 February 2021

The sun as imaged on 26 February 2021 around 11:34 UTC.
Figure 66: The sun as imaged on 26 February 2021 around 11:34 UTC.
On 26 February some nice activity could be seen on the sun. Solar spot AR2804, an active region AR2805 and a large protuberance were visible at the same time.


Solar spot AR2804 as imaged on 26 February 2021 around 11:34 UTC.
Figure 67: Solar spot AR2804 as imaged on 26 February 2021 around 11:34 UTC.


The largest protuberance of 26 February 2021.
Figure 68: The largest protuberance of 26 February 2021.


9 November 2020 with sunspot AR2781

The sun as imaged on 9 November 2020 with sunspot AR2781.
Figure 69: The sun as imaged on 9 November 2020 with sunspot AR2781.
Slowly but surely the Sun it showing more activity. On 9 November 2020 sunspot AR2781 was well visible and imaged using the Lunt LS80THA. Adjacent image is taken with the ZWO ASI174MM camera directly mounted on the blocking filter (so without Barlow). Processing was done using an inverted histogram.


Detail of sunspot AR2781 as imaged on 9 November 2020.
Figure 70: Detail of sunspot AR2781 as imaged on 9 November 2020.
Using a TeleVue 4x PowerMate behind the blocking filter of the Lunt LS80THA, sunspot AR2781 was imaged in some more detail.


Sunspot AR2781 as imaged on 9 November 2020 with the SkyWatcher Esprit 150ED.
Figure 71: Sunspot AR2781 as imaged on 9 November 2020 with the SkyWatcher Esprit 150ED.
Using the SkyWatcher Esprit 150ED and a white-light filter, sunspot AR2781 was imaged in full spectrum.


31 July 2020

The sun a simaged on 31 August 2020 around 09:21 UTC.
Figure 72: The sun a simaged on 31 August 2020 around 09:21 UTC.
On 30 and 31 July 2020 a nice long protuberance was visible at the sun. Imaging was done on 31 June with the Lunt LS80THA in combination with a TeleVue 4x PowerMate and ZWO ASI174MM. During 60 seconds 7k frames were captured 10% of which were stacked using AutoStakkert. Post-processing done in PSP.


The full Sun captured on 31 July 2020.
Figure 73: The full Sun captured on 31 July 2020.
That same day I also captured the Sun in full. During 2 minutes 4809 frames were captured, 30 percent of which was stacked using AutoStakkert!. Stretching was done using the inverted method in IMPPG, post-processing in PSP using the method described in my second article on solar processing.


19 June 2020

The Sun as imaged on 19 June 2020.
Figure 74: The Sun as imaged on 19 June 2020.
In June 2020 I learned a new technique of solar imaging processing. Using ImPPG it is possible to invert the histogram, a method I explain in more detail here. Using this method allows to show more surface detail and protuberances.
The image was taken with the Lunt LS80THA and ZWO ASI174MM monochrome camera.


25 May 2020

The Sun as imaged on 25 May 2020.
Figure 75: The Sun as imaged on 25 May 2020.
On 25 May 2020 a nice prominence was visible, captured again with the Lunt LS80THA with a 4x Barlow and ZWO ASI174MM.


20 September 2019

A solar flare imaged on 20 September 2019.
Figure 76: A solar flare imaged on 20 September 2019.
On 20 September 2019, with the assistance of two high school students, we imaged the sun around 08:45am UTC. Imaging was done using the Lunt LS80THA in combination with a 4x PowerMate and ZWO ASI174MM, focusing was done manual. In 2 minutes time 2584 frames were captured, 30 percent of which were stacked. Some processing in AutoStakkert, IMPPG, and Paint Shop Pro resulted in this rather pleasing image. The Earth has been added to the image at the same scale.


29 July 2019

A solar flare as seen on 29 July 2019.
Figure 77: A solar flare as seen on 29 July 2019.
Recently I received a M42 to 2" adapter for the blocking filter of my Lunt. This adapter allows to include a barlow in the optical path. On 29 July 2019 I tested it for the first time using a TeleVue 4x PowterMate and ZWO ASI174MM. A movie of 10,000 frames was shot in 40 seconds, processed in AutoStakkert using sharpening and finally enhanced, colourised and sharpened in PSP. In the lower left corner the Earth is shown at scale.


9 May 2019

The sun as imaged on 9 May 2019. It seems sun spot season started again.
Figure 78: The sun as imaged on 9 May 2019. It seems sun spot season started again.
Ever since InFINNity Deck became operational the sun was quite boring, only occasionally showing some activity. That changed a few weeks ago and now it starts to be interesting again as can be seen in this image. The large sun spot at the right is number 2741.


19 March 2019

A better picture of the sun, taken on 19 March 2019, with a turbo-prop plane flying past.
Figure 79: A better picture of the sun, taken on 19 March 2019, with a turbo-prop plane flying past.
In March 2019 I experimented with the Lunt to improved the quality of the images taken through the Lunt. From another Dutch amateur astronomer I learned to improve my processing. Although the Sun is still quite dull, having something in the foreground makes the image much more attractive. Just above the cockpit a small sunspot can be seen, while above the left wing a protuberance can be spotted.


My first attempt from InFINNity Deck on 9 June 2018

The sun imaged on 9 June 2018 using the Lunt. At nine o'clock a small protuberance can be seen.
Figure 80: The sun imaged on 9 June 2018 using the Lunt. At nine o'clock a small protuberance can be seen.
Currently (2018) the sun's activity is at its lowest point, resulting in a rather dull view with only minor protuberances and an occasional sun spot.
figure 80 was my first attempt to image the sun and was a rather mediocre attempt. As can be seen in the following images my skills gradually improved.


Solar images before 2018

Until the construction of InFINNity Deck I had no astronomical telescopes of my own. Before that time I used geodetic instruments like the 1969 Wild T2E or 1937 Wild T3 (astronomic) to look at celestial objects. In addition I borrowed a Celestron C5 telescope in 2015 from the Alkmaarse Weer- en Sterrenkundige Vereniging Metius.


Partial solar eclipse 20 March 2015

The partial solar eclipse of 20 March 2015 as imaged through a C5.
Figure 81: The partial solar eclipse of 20 March 2015 as imaged through a C5.
On 20 March 2015 a partial solar eclipse could be seen from the Netherlands, although "seen" has to be taken with a grain of salt as most of the day the Netherlands was covered with thick cloud. I was lucky to have some moments where the cloud cover became thinner and the Sun could be spotted with the naked eye. Adjacent image is one of six taken that day. Imaging was done afocal using a standard hand-held compact camera behind the Celestron C5 using the clouds as the only filter.


The partial solar eclipse of 20 March 2015 as imaged directly around 09:30UTC.
Figure 82: The partial solar eclipse of 20 March 2015 as imaged directly around 09:30UTC.
Using that same camera I took this image, clearly showing the lousy sky-conditions of that day.
The eclipse started at around 08:30UTC, maximum occurred at around 09:37UTC with a coverage of about 82%, while it ended at around 10:48UTC.


Venus-transit on 8 June 2004

The Venus-transit of 8 June 2004.
Figure 83: The Venus-transit of 8 June 2004.
On 8 June 2004 the first of two Venus-transits of the 21st century took place. At the time I had no telescope, but used a 1969 Wild T2E to project the Sun on a piece of blank paper while sitting indoors. In adjacent image the transit as imaged around 7am UTC is shown. Being an instrument with an erect view, and therefore projecting an inverted image, south is shown upwards.
Slightly off-centred the deliberately defocused horizontal and vertical cross-hairs can still be faintly seen.


The theodolite set-up used to image the 2004 transit of Venus.
Figure 84: The theodolite set-up used to image the 2004 transit of Venus.
Adjacent image shows how I captured the 2004 transit of Venus using the 1969 Wild T2E. A page of a local newspaper served well as a shade around the theodolite's telescope. An A4-size sheet of blank paper was used to catch the Sun's image.
Eight years later, on 6 June 2012, the second Venus-transit of the 21st century occurred, but was hardly visible in the Netherlands, partially because of its early time of day (22:04UTC on 5 June until 4:55UTC on 6 June) and partially due to heavy cloudcover.


If you have any questions and/or remarks please let me know.


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