Hi Alfred
Very hard to get someone engaged in daily obs of the sun because of the heat on prolong exposure to the sun. Also its pretty uncomfortable., and those solar scope/filters are not cheap.
Moreover, after prolong(approx 11+ years) exposure to the sun, I learn that even optical coating turn into cataract! It happens to my 8 cm refractor, bought new from astroscientific.
Now for today's observation.
In 540nm.... Sunspot 2810 show up as 2 spots separated by a lightbridge.
In Ha...... 2 bright spots in the northern belt., one at 2810 location and another with no spot visible.
No bright region detected in southern belt.The prominence that showed up today are pretty small. Also one small filament seen near the bright region in the northern belt and one near the middle of the southern belt.
In Cak...... Besides the 2 regions mentioned above shows up in also cak., A BRIGHT REGION SHOW UP IN NEAR THE CENTRE OF THE SOUTHERN BELT..... a surprise.
Observed between 10am to 1 pm.
Solar cycle 25
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Re: Solar cycle 25
Today sun......
Almost total blackout in all activities.
At 540nm..... No sunspot., blank sun.
At Ha 0.5A bandwidth...... A very very small prominence at northern belt edge rotating out of view., followed by a small filament. No bright region at all.
In Cak..... The above region in the northern belt show up in cak with 2 bright spot. That all.
Overall, the show of activities in this cycle is very low., and hence very different from other cycles I had observed.
Almost total blackout in all activities.
At 540nm..... No sunspot., blank sun.
At Ha 0.5A bandwidth...... A very very small prominence at northern belt edge rotating out of view., followed by a small filament. No bright region at all.
In Cak..... The above region in the northern belt show up in cak with 2 bright spot. That all.
Overall, the show of activities in this cycle is very low., and hence very different from other cycles I had observed.
- yltansg
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- Favourite scope: Borg 76 + Solar Scope SF50
- Location: Bukit Batok
Re: Solar cycle 25
Thanks Mr Chia for the update on the Sun on 2 Apr.
Here is a belated posting on the images taken on 20 March.
This Hydrogen-Alpha image was from Global Oscillation Network Group (GONG). It showed the position of Active Region 2810.

The following images are taken by me using a Celestron 11" SCT.
Fitted with a Daystar Quark H-Alpha eyepiece, Chromosphere Model, my C11 produced this zoom-in image of the filament and the nearby Active Region in H-Alpha, :

Using a set of Calcium-K filters fitted on the same C11, we can see the lower chromosphere lighted up by Calcium atoms:

And this is how the Calcium full disk looked like from GONG:

Alfred
Here is a belated posting on the images taken on 20 March.
This Hydrogen-Alpha image was from Global Oscillation Network Group (GONG). It showed the position of Active Region 2810.

The following images are taken by me using a Celestron 11" SCT.
Fitted with a Daystar Quark H-Alpha eyepiece, Chromosphere Model, my C11 produced this zoom-in image of the filament and the nearby Active Region in H-Alpha, :

Using a set of Calcium-K filters fitted on the same C11, we can see the lower chromosphere lighted up by Calcium atoms:

And this is how the Calcium full disk looked like from GONG:

Alfred
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Re: Solar cycle 25
Thanks Alfred for the nice and detailed zoom in photos..
However, up to now, I notice this cycle 25 is drastically different from the past 3 that I had observed.
One is that activities had on several occasions die out completely..... Like now.
Another is that even prominence is a no show..... Only always small and similar to those at the beginning of every cycle., not to mention that the sunspots are small and frequently Featureless.
Only super zoomin like Alfred s photo show interesting features. Thanks Alfred.
However, up to now, I notice this cycle 25 is drastically different from the past 3 that I had observed.
One is that activities had on several occasions die out completely..... Like now.
Another is that even prominence is a no show..... Only always small and similar to those at the beginning of every cycle., not to mention that the sunspots are small and frequently Featureless.
Only super zoomin like Alfred s photo show interesting features. Thanks Alfred.
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- Joined: Mon Nov 03, 2008 4:45 pm
Re: Solar cycle 25
Yesterday sun(14 april 2021)
In 540nm..... Very interesting. 2 group of 2 bigger spot and then in between the two group 5 small sunspot. The whole region is very small and hence hard to capture on photos.
In Cak..... Each of the 2 bigger group can be seen in cak as a spot. The rest become a bright region in cak. Overall quite a small bright region.
In Ha..... Only a bright region seen associated with whats observed in the southern belt. Its named sunspot 2814.A small prominence observed at edge of southern belt.
In 540nm..... Very interesting. 2 group of 2 bigger spot and then in between the two group 5 small sunspot. The whole region is very small and hence hard to capture on photos.
In Cak..... Each of the 2 bigger group can be seen in cak as a spot. The rest become a bright region in cak. Overall quite a small bright region.
In Ha..... Only a bright region seen associated with whats observed in the southern belt. Its named sunspot 2814.A small prominence observed at edge of southern belt.
- yltansg
- Posts: 358
- Joined: Mon Aug 31, 2009 3:35 pm
- Favourite scope: Borg 76 + Solar Scope SF50
- Location: Bukit Batok
Re: Solar cycle 25
A CAK observation in CAK on 15 Apr from 8:40 to 9:15am. On the SDO website, the active region AR2814 is in the southern hemisphere around the 4-5 O'clock bearing.

Using a Celestron C11 SCT, I made the following animation from 60 still frames:

Best viewed on a desktop computer. You can see the changes in the CAK atmosphere.
Alfred

Using a Celestron C11 SCT, I made the following animation from 60 still frames:

Best viewed on a desktop computer. You can see the changes in the CAK atmosphere.
Alfred