Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Thursday, 20 August 2026

‹ 18.08.2026 2026 21.08.2026 ›

Photosphere sunspot drawing and RDS evaluation

20.08.2026 photosphere drawing

High-resolution scan (3230 px)

Time
08:35 UT
Observer
Melike ERYILMAZ
g
4
f
15
R
55
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · EHI – 6Group 1 · EHI – 6 Group 2 · AX_ – 2Group 2 · AX_ – 2 Group 3 · HS_ – 4Group 3 · HS_ – 4 Group 4 · BXI – 3Group 4 · BXI – 3
RDS data file (.gzd) 
[Gözlem]
Tarih=20.08.2026
Saat=08:35
Gözlemci=Melike ERYILMAZ
KontrolEden=Melike ERYILMAZ
Durumaçısı=17.71
Enlemaçısı=6.86
Boylamaçısı=124.28
Boylamfark=2
GKalite=3
GDurum=K.T
Kuzeyaçısı=-0.9
Sırano=20545
AyRasatNo=18
RasatÖnceki=18.08.2026
RasatSonraki=21.08.2026

[Leke Grupları]
Grupsayısı=4:3:1
LekeSayısı=15:12:3
RölatifSayı=55:42:13
01=EHI 06 +03.604 +70.334 194.614 +0.000 0000 0 +05.666 +76.419 +01.542 +64.249 +03.604 +76.219 +03.604 +64.449
02=AX_ 02 +09.206 +40.189 164.469 +0.000 0000 0 +10.210 +40.702 +08.202 +39.676 +09.206 +40.202 +09.206 +40.176
03=HS_ 04 +04.596 -75.676 048.604 +0.000 0000 0 +06.137 -72.300 +03.550 -79.520 +04.596 -72.566 +04.596 -78.786
04=BXI 03 -08.663 +44.942 169.222 +0.000 0000 0 -08.420 +47.364 -09.284 +42.520 -08.663 +46.864 -08.663 +43.200
20260820.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 →

2026/20260820_me · ME · 6 frames · 128.6 MB · 08:39:44–08:42:15 UT

08:40:14 UT · 30 ms 08:41:14 UT · 30 ms 08:42:15 UT · 30 ms 08:40:44 UT · 60 ms · over-exposed 08:39:44 UT · 60 ms · over-exposed 08:41:44 UT · 60 ms · over-exposed

Coronado H-α animations from frame sequences

No Coronado observation for this day.