Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Thursday, 23 April 2026

‹ 21.04.2026 2026 24.04.2026 ›

Photosphere sunspot drawing and RDS evaluation

23.04.2026 photosphere drawing

High-resolution scan (3229 px)

Time
10:15 UT
Observer
Ergün EGE
g
4
f
25
R
65
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · DSI – 5Group 1 · DSI – 5 Group 2 · AX_ – 1Group 2 · AX_ – 1 Group 3 · DHC – 18Group 3 · DHC – 18 Group 4 · HS_ – 1Group 4 · HS_ – 1
RDS data file (.gzd) 
[Gözlem]
Tarih=23.04.2026
Saat=10:15
Gözlemci=Ergün EGE
KontrolEden=İrem ÖZDEMİR
Durumaçısı=-25.25
Enlemaçısı=-4.92
Boylamaçısı=257.53
Boylamfark=1
GKalite=3
GDurum=B.A , Y.B
Kuzeyaçısı=-0.5
Sırano=20453
AyRasatNo=14
RasatÖnceki=21.04.2026
RasatSonraki=24.04.2026

[Leke Grupları]
Grupsayısı=4:3:1
LekeSayısı=25:24:1
RölatifSayı=65:54:11
01=DSI 05 +15.468 +54.199 311.729 +0.000 0000 0 +16.952 +60.336 +13.983 +48.620 +15.468 +60.136 +15.468 +48.262
02=AX_ 01 +07.765 +49.990 307.520 +0.000 0000 0 +08.140 +50.507 +07.390 +49.473 +07.765 +50.700 +07.765 +49.973
03=DHC 18 +15.721 -32.592 224.938 +0.000 0000 0 +17.311 -26.357 +14.131 -38.826 +15.721 -26.557 +15.721 -38.626
04=HS_ 01 -10.831 -46.412 211.118 +0.000 0000 0 -10.610 -45.779 -11.602 -47.440 -10.831 -46.810 -10.831 -46.743
20260423.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 →

2026/20260423 · · 1 frames · 21.4 MB · 10:09:54 UT

10:09:54 UT · 30 ms

Coronado H-α animations from frame sequences

No Coronado observation for this day.