Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Monday, 4 August 2025

‹ 01.08.2025 2025 05.08.2025 ›

Photosphere sunspot drawing and RDS evaluation

04.08.2025 photosphere drawing

High-resolution scan (3230 px)

Time
10:20 UT
Observer
Ergün EGE
g
6
f
49
R
109
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · EKC – 18Group 1 · EKC – 18 Group 2 · AX_ – 2Group 2 · AX_ – 2 Group 3 · DSI – 19Group 3 · DSI – 19 Group 4 · HK_ – 3Group 4 · HK_ – 3 Group 5 · HA_ – 2Group 5 · HA_ – 2 Group 6 · CSO – 5Group 6 · CSO – 5
RDS data file (.gzd) 
[Gözlem]
Tarih=4.08.2025
Saat=10:20
Gözlemci=Ergün EGE
KontrolEden=Olcay PLEVNE
Durumaçısı=12.22
Enlemaçısı=6.02
Boylamaçısı=112.39
Boylamfark=1
GKalite=3
GDurum=K.T
Kuzeyaçısı=-0.4
Sırano=20314
AyRasatNo=2
RasatÖnceki=01.08.2025
RasatSonraki=05.08.2025

[Leke Grupları]
Grupsayısı=6:5:1
LekeSayısı=49:44:5
RölatifSayı=109:94:15
01=EKC 18 +11.135 +55.420 167.810 +0.000 0000 0 +13.373 +62.240 +08.898 +48.601 +11.135 +62.400 +11.135 +48.801
02=AX_ 02 +09.847 +28.387 140.777 +0.000 0000 0 +10.487 +29.190 +09.208 +27.754 +09.847 +28.605 +09.847 +28.169
03=DSI 19 +05.774 -12.264 100.126 +0.000 0000 0 +07.336 -07.154 +04.211 -17.374 +05.774 -07.354 +05.774 -17.174
04=HK_ 03 +12.685 -13.762 098.628 +0.000 0000 0 +13.835 -12.203 +11.536 -15.321 +12.685 -12.703 +12.685 -14.821
05=HA_ 02 +21.687 -79.344 033.460 +0.000 0000 0 +22.831 -76.941 +20.542 -81.747 +21.687 -77.441 +21.687 -81.247
06=CSO 05 -12.129 +20.518 132.908 +0.000 0000 0 -10.882 +23.307 -13.376 +17.728 -12.129 +23.107 -12.129 +17.928
20250804.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 →

2025/20250804 · · 8 frames · 171.4 MB · 10:17:14–10:32:41 UT

10:17:14 UT · 40 ms 10:26:54 UT · 40 ms 10:18:34 UT · 50 ms · over-exposed 10:31:29 UT · 50 ms · over-exposed 10:32:03 UT · 60 ms · over-exposed 10:23:09 UT · 60 ms · over-exposed 10:26:12 UT · 70 ms · over-exposed 10:32:41 UT · 70 ms · over-exposed

Coronado H-α animations from frame sequences

No Coronado observation for this day.