Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Friday, 21 August 2026

‹ 20.08.2026 2026 22.08.2026 ›

Photosphere sunspot drawing and RDS evaluation

21.08.2026 photosphere drawing

High-resolution scan (3230 px)

Time
06:35 UT
Observer
Melike ERYILMAZ
g
7
f
15
R
85
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · HS_ – 1Group 1 · HS_ – 1 Group 2 · AX_ – 2Group 2 · AX_ – 2 Group 3 · EHC – 7Group 3 · EHC – 7 Group 4 · AX_ – 1Group 4 · AX_ – 1 Group 5 · AX_ – 1Group 5 · AX_ – 1 Group 6 · AX_ – 2Group 6 · AX_ – 2 Group 7 · HH_ – 1Group 7 · HH_ – 1
RDS data file (.gzd) 
[Gözlem]
Tarih=21.08.2026
Saat=06:35
Gözlemci=Melike ERYILMAZ
KontrolEden=Melike ERYILMAZ
Durumaçısı=18
Enlemaçısı=6.9
Boylamaçısı=112.17
Boylamfark=3
GKalite=3
GDurum=K.T
Kuzeyaçısı=-0.9
Sırano=20546
AyRasatNo=19
RasatÖnceki=20.08.2026
RasatSonraki=22.08.2026

[Leke Grupları]
Grupsayısı=7:3:4
LekeSayısı=15:10:5
RölatifSayı=85:40:45
01=HS_ 01 +01.859 +76.663 188.833 +0.000 0000 0 +03.430 +78.558 +00.675 +74.768 +01.859 +78.580 +01.859 +75.268
02=AX_ 02 +08.609 +52.888 165.580 +0.000 0000 0 +09.849 +53.655 +07.369 +52.120 +08.609 +53.156 +08.609 +52.620
03=EHC 07 +04.427 -64.602 047.568 +0.000 0000 0 +06.742 -57.122 +02.112 -72.830 +04.427 -57.322 +04.427 -71.883
04=AX_ 01 -07.349 +65.395 177.565 -1.000 0000 0 -07.349 +65.395 -07.349 +65.395
05=AX_ 01 -09.793 +61.573 173.743 -1.000 0000 0 -09.793 +61.573 -09.793 +61.573
06=AX_ 02 -15.861 +35.975 148.145 +0.000 0000 0 -14.994 +37.965 -16.729 +33.985 -15.861 +37.765 -15.861 +34.185
07=HH_ 01 -07.659 -74.986 037.184 +0.000 0000 0 -06.606 -72.810 -08.712 -77.161 -07.659 -73.311 -07.659 -76.661
20260821.gzd

Chromosphere (H-α) FITS frames

H-α

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 →

2026/20260821_me · ME · 6 frames · 128.6 MB · 06:41:54–06:44:24 UT

06:42:24 UT · 30 ms 06:44:24 UT · 30 ms 06:43:24 UT · 30 ms 06:43:54 UT · 60 ms · over-exposed 06:41:54 UT · 60 ms · over-exposed 06:42:54 UT · 60 ms · over-exposed

Coronado H-α animations from frame sequences

No Coronado observation for this day.