Images 21.08.2025 · Istanbul University Observatory Solar Observations

Solar Images Thursday, 21 August 2025

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Photosphere sunspot drawing and RDS evaluation

High-resolution scan (3229 px)

Time: 07:00 UT
Observer: Burçin TANIK
g: 4
f: 8
R: 48
Seeing: 3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · BXI – 3

Group 2 · HH_ – 1

Group 3 · DSO – 3

Group 4 · HR_ – 1

RDS data file (.gzd)

[Gözlem]
Tarih=21.08.2025
Saat=07:00
Gözlemci=Burçin TANIK
KontrolEden=Ergün EGE
Durumaçısı=18.08
Enlemaçısı=6.91
Boylamaçısı=249.49
Boylamfark=3
GKalite=3
GDurum=G.T
Kuzeyaçısı=-0.5
Sırano=20328
AyRasatNo=16
RasatÖnceki=20.08.2025
RasatSonraki=22.08.2025

[Leke Grupları]
Grupsayısı=4:2:2
LekeSayısı=8:4:4
RölatifSayı=48:24:24
01=BXI 03 +07.791 -28.328 221.162 +0.000 0000 0 +08.254 -26.313 +07.328 -30.343 +07.791 -26.813 +07.791 -29.843
02=HH_ 01 +10.353 -72.460 177.444 +0.000 0000 0 +11.799 -69.826 +08.908 -74.266 +10.353 -70.740 +10.353 -74.180
03=DSO 03 -18.126 +09.110 258.600 +0.000 0000 0 -17.558 +11.413 -18.694 +06.808 -18.126 +10.912 -18.126 +07.307
04=HR_ 01 -08.186 -39.986 209.504 +0.000 0000 0 -07.684 -39.147 -08.688 -40.826 -08.186 -39.646 -08.186 -40.326

20250821.gzd

Chromosphere (H-α) FITS frames

The images are made automatically with a fixed, gentle rule: uneven illumination and most of the limb darkening are removed, and the brightness is shown on a linear scale (no sharpening); prominences get their own scale outside the limb. Frames are ordered by sharpness (seeing); frames without the Sun (darks, bias) come last. Method →

2025/20250821_bto · BTO · 4 frames · 85.7 MB · 07:15:23–07:20:25 UT

07:17:44 UT · 30 ms

07:19:38 UT · 50 ms

07:15:23 UT · 70 ms · over-exposed

07:20:25 UT · 70 ms · over-exposed

Coronado H-α animations from frame sequences

No Coronado observation for this day.