Search found 388 matches

by yltansg
Sat Oct 09, 2021 9:31 pm
Forum: Astronomy Events & Observation Sessions
Topic: Solar cycle 25
Replies: 133
Views: 12888

Re: Solar cycle 25

8 Oct 21, A survey in Calcium-K wavelength. AR2882 started as a stable Active Region, after discharging a few C-Class flares this week has evolved into a restless AR with 'beta-gamma' magnetic field with energy for M-Class flares. This is an image from Solar Dynamic Observatory: https://blogger.goog...
by yltansg
Wed Oct 06, 2021 10:28 pm
Forum: Astronomy Events & Observation Sessions
Topic: Solar cycle 25
Replies: 133
Views: 12888

Re: Solar cycle 25

Hi Vernonfarmer39, The image was taken using a Celestron C11 fitted with a D-ERF, a Daystar Quark Chromosphere and a Basler ace acA1920-155um camera. https://1.bp.blogspot.com/-BBb2h2PeitM/YN09rSVIXWI/AAAAAAABC4E/vTEouyRoA58DnTrP2TQo7mQ6814hu19cwCLcBGAsYHQ/s2048/IMG_20210701_094830.jpg I also have o...
by yltansg
Fri Sep 24, 2021 7:55 pm
Forum: Astronomy Events & Observation Sessions
Topic: Solar cycle 25
Replies: 133
Views: 12888

Re: Solar cycle 25

Adding a pseudo-coloured image of AR2871:

Image

Cheers.

Alfred
by yltansg
Fri Sep 24, 2021 7:22 pm
Forum: Astronomy Events & Observation Sessions
Topic: Solar cycle 25
Replies: 133
Views: 12888

Re: Solar cycle 25

Old sunspot AR2860 is returning after a 2-week transit around the far side of the sun. Per tradition, it has been renumbered AR2871. It has returned after a two-week trip around the farside of the sun. During its previous appearance in late August, the sunspot produced 1 M-class flare and 21 C-class...
by yltansg
Sun Sep 19, 2021 8:57 am
Forum: Buy and Sell
Topic: WTB: ASI1600MM Pro (Found, Closed)
Replies: 1
Views: 537

WTB: ASI1600MM Pro (Found, Closed)

Please let me know if you have one for sale.

Thanks.

Alfred
by yltansg
Tue Sep 14, 2021 9:08 pm
Forum: Astronomy Events & Observation Sessions
Topic: Solar cycle 25
Replies: 133
Views: 12888

Re: Solar cycle 25

Thanks, Mr Chia for your kind words. Here is another image from the same 11 Sep session. This is a close-up of AR2868:
Image

Alfred
by yltansg
Mon Sep 13, 2021 10:00 pm
Forum: Astronomy Events & Observation Sessions
Topic: Solar cycle 25
Replies: 133
Views: 12888

Re: Solar cycle 25

This is a closer look at AR2866 on 11 Sep 21

Image

Do a right click to see the image in its full resolution.

Alfred
by yltansg
Mon Sep 13, 2021 10:36 am
Forum: Astronomy Events & Observation Sessions
Topic: Solar cycle 25
Replies: 133
Views: 12888

Re: Solar cycle 25

Stunning full disc image of the Sun. Great shots! Thanks for your compliments, Warp 7. The posting at https://solarchatforum.com/viewtopic.php?f=4&t=33334 has attracted several positive comments and a Solar Picture of the Day https://1.bp.blogspot.com/-w0ONj68M5AE/YT6hLiiRebI/AAAAAAABHlg/MBLKLm...
by yltansg
Sun Sep 12, 2021 7:39 pm
Forum: Astronomy Events & Observation Sessions
Topic: Solar cycle 25
Replies: 133
Views: 12888

Re: Solar cycle 25

This is the actual colour of the upper atmosphere of the Sun, illuminated by red light emitted by hydrogen atoms. I used a 656.28 nm hydrogen alpha etalon to filter out all the other light and capture the features lighted by the red light. https://1.bp.blogspot.com/-B7KIK6HI0NQ/YT3gVWs18KI/AAAAAAABH...