Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Tuesday, 16 September 2025

‹ 15.09.2025 2025 17.09.2025 ›

Photosphere sunspot drawing and RDS evaluation

16.09.2025 photosphere drawing

High-resolution scan (3230 px)

Time
07:30 UT
Observer
Korhan YELKENCİ
g
8
f
36
R
116
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · CAI – 3Group 1 · CAI – 3 Group 2 · CSI – 7Group 2 · CSI – 7 Group 3 · AX_ – 3Group 3 · AX_ – 3 Group 4 · CAI – 3Group 4 · CAI – 3 Group 5 · BXI – 8Group 5 · BXI – 8 Group 6 · AX_ – 2Group 6 · AX_ – 2 Group 7 · DAI – 7Group 7 · DAI – 7 Group 8 · AX_ – 3Group 8 · AX_ – 3 Group 9Group 9
RDS data file (.gzd) 
[Gözlem]
Tarih=16.09.2025
Saat=07:30
Gözlemci=Korhan YELKENCİ
KontrolEden=Süleyman FİŞEK
Durumaçısı=24.27
Enlemaçısı=7.19
Boylamaçısı=265.8
Boylamfark=2
GKalite=3
GDurum=K.T
Kuzeyaçısı=-0.5
Sırano=20347
AyRasatNo=13
RasatÖnceki=15.09.2025
RasatSonraki=17.09.2025

[Leke Grupları]
Grupsayısı=8:4:4
LekeSayısı=36:16:20
RölatifSayı=116:56:60
01=CAI 03 +26.495 +17.960 283.760 23.112 0000 0 +27.779 +20.722 +25.212 +15.198 +27.579 +20.486 +25.412 +15.398
02=CSI 07 +10.981 -22.307 243.493 +0.000 0000 0 +12.638 -16.513 +09.323 -28.101 +10.981 -16.713 +10.981 -27.901
03=AX_ 03 +13.404 -32.114 233.686 +0.000 0000 0 +13.872 -31.197 +12.936 -33.300 +13.404 -31.562 +13.404 -32.665
04=CAI 03 +04.582 -53.962 211.838 +0.000 0000 0 +05.338 -50.647 +03.827 -57.277 +04.582 -51.147 +04.582 -56.777
05=BXI 08 -16.982 -24.629 241.171 23.823 0000 0 -15.611 -21.789 -18.354 -27.468 -15.862 -22.680 -18.154 -27.268
06=AX_ 02 -09.700 -55.700 210.793 +0.000 0000 0 -08.630 -53.797 -09.511 -56.218 -09.700 -54.990 -09.700 -56.410
07=DAI 07 -15.215 -57.542 208.258 21.360 0000 0 -12.682 -51.287 -17.747 -63.798 -13.300 -51.874 -17.547 -63.598
08=AX_ 03 -15.831 -74.618 191.182 +0.000 0000 0 -14.727 -73.440 -16.936 -75.796 +00.000 +00.000 +00.000 +00.000
20250916.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 →

2025/20250916_ky · KY · 8 frames · 171.4 MB · 07:55:50–07:59:21 UT

07:57:21 UT · 30 ms 07:55:50 UT · 30 ms 07:58:21 UT · 30 ms 07:57:51 UT · 60 ms · over-exposed 07:58:51 UT · 60 ms · over-exposed 07:56:20 UT · 60 ms · over-exposed 07:59:21 UT 07:56:51 UT

Coronado H-α animations from frame sequences

No Coronado observation for this day.