Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Thursday, 11 September 2025

‹ 10.09.2025 2025 12.09.2025 ›

Photosphere sunspot drawing and RDS evaluation

11.09.2025 photosphere drawing

High-resolution scan (3230 px)

Time
06:40 UT
Observer
Korhan YELKENCİ
g
5
f
31
R
81
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · CAI – 4Group 1 · CAI – 4 Group 2 · BXI – 8Group 2 · BXI – 8 Group 3 · AX_ – 3Group 3 · AX_ – 3 Group 4 · HS_ – 2Group 4 · HS_ – 2 Group 5 · DAI – 14Group 5 · DAI – 14
RDS data file (.gzd) 
[Gözlem]
Tarih=11.09.2025
Saat=06:40
Gözlemci=Korhan YELKENCİ
KontrolEden=Süleyman FİŞEK
Durumaçısı=23.38
Enlemaçısı=7.24
Boylamaçısı=332.27
Boylamfark=3
GKalite=3
GDurum=K.T
Kuzeyaçısı=-0.2
Sırano=20343
AyRasatNo=9
RasatÖnceki=10.09.2025
RasatSonraki=12.09.2025

[Leke Grupları]
Grupsayısı=5:3:2
LekeSayısı=31:15:16
RölatifSayı=81:45:36
01=CAI 04 +28.288 +78.826 051.960 13.626 0000 0 +29.578 +83.517 +26.997 +74.135 +29.365 +83.317 +27.197 +74.335
02=BXI 08 +07.140 +55.211 027.481 26.220 0000 0 +08.442 +57.677 +05.839 +52.746 +08.201 +57.406 +06.390 +53.100
03=AX_ 03 +25.142 +30.467 002.737 +0.000 0000 0 +25.551 +31.514 +24.734 +29.421 +25.142 +31.130 +25.142 +29.920
04=HS_ 02 -13.207 +39.880 011.358 +0.000 0000 0 -11.841 +40.630 -14.573 +37.546 -13.207 +40.922 -13.207 +38.838
05=DAI 14 -14.109 +28.246 000.516 23.233 0000 0 -11.766 +33.484 -16.452 +23.900 -11.966 +33.263 -16.252 +23.209
20250911.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 →

2025/20250911_ky · KY · 8 frames · 171.4 MB · 07:00:29–07:03:59 UT

07:02:59 UT · 30 ms 07:01:59 UT · 30 ms 07:03:29 UT · 60 ms · over-exposed 07:00:29 UT · 30 ms 07:02:29 UT · 60 ms 07:00:59 UT · 60 ms 07:03:59 UT 07:01:29 UT

Coronado H-α animations from frame sequences

No Coronado observation for this day.