Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Wednesday, 17 September 2025

‹ 16.09.2025 2025 18.09.2025 ›

Photosphere sunspot drawing and RDS evaluation

17.09.2025 photosphere drawing

High-resolution scan (3231 px)

Time
08:15 UT
Observer
Süleyman FİŞEK
g
8
f
47
R
127
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · AX_ – 1Group 1 · AX_ – 1 Group 2 · DSC – 13Group 2 · DSC – 13 Group 3 · AX_ – 1Group 3 · AX_ – 1 Group 4 · DHI – 5Group 4 · DHI – 5 Group 5 · HH_ – 1Group 5 · HH_ – 1 Group 6 · DSC – 16Group 6 · DSC – 16 Group 7 · EHO – 5Group 7 · EHO – 5 Group 8 · CRI – 5Group 8 · CRI – 5
RDS data file (.gzd) 
[Gözlem]
Tarih=17.09.2025
Saat=08:15
Gözlemci=Süleyman FİŞEK
KontrolEden=Süleyman FİŞEK
Durumaçısı=24.44
Enlemaçısı=7.17
Boylamaçısı=252.19
Boylamfark=2
GKalite=3
GDurum=G.T , K.T
Kuzeyaçısı=-0.6
Sırano=20348
AyRasatNo=14
RasatÖnceki=16.09.2025
RasatSonraki=18.09.2025

[Leke Grupları]
Grupsayısı=8:5:3
LekeSayısı=47:21:26
RölatifSayı=127:71:56
01=AX_ 01 +25.714 +34.981 287.171 -1.000 0000 0 +25.714 +34.981 +25.714 +34.981
02=DSC 13 +10.217 -06.425 245.765 +0.000 0000 0 +12.170 -02.160 +08.264 -10.689 +10.217 -02.360 +10.217 -10.489
03=AX_ 01 +13.765 -17.202 234.988 -1.000 0000 0 +13.765 -17.202 +13.765 -17.202
04=DHI 05 +04.865 -39.116 213.740 +0.000 0000 0 +05.823 -35.587 +03.907 -42.646 +04.865 -35.787 +04.865 -42.446
05=HH_ 01 +10.995 -77.540 175.136 +0.000 0000 0 +12.238 -74.879 +09.753 -79.230 +10.995 -75.865 +10.995 -79.215
06=DSC 16 -16.611 -09.110 243.800 +0.000 0000 0 -15.610 -05.711 -18.160 -12.510 -16.611 -05.911 -16.611 -12.310
07=EHO 05 -15.200 -43.285 208.905 +0.000 0000 0 -12.811 -37.130 -17.193 -49.557 -15.200 -37.213 -15.200 -49.357
08=CRI 05 -15.332 -59.703 192.487 +0.000 0000 0 -13.989 -58.702 -16.676 -60.704 +00.000 +00.000 +00.000 +00.000
20250917.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 →

2025/20250917_sf · SF · 8 frames · 171.4 MB · 08:23:52–08:27:22 UT

08:26:22 UT · 30 ms 08:23:52 UT · 30 ms 08:25:22 UT · 30 ms 08:25:52 UT · 60 ms · over-exposed 08:26:52 UT · 60 ms · over-exposed 08:24:22 UT · 60 ms · over-exposed 08:27:22 UT 08:24:52 UT

Coronado H-α animations from frame sequences

No Coronado observation for this day.