Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Friday, 17 July 2026

‹ 15.07.2026 2026 18.07.2026 ›

Photosphere sunspot drawing and RDS evaluation

17.07.2026 photosphere drawing

High-resolution scan (3230 px)

Time
07:50 UT
Observer
Melike ERYILMAZ
g
4
f
9
R
49
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · AX_ – 1Group 1 · AX_ – 1 Group 2 · HS_ – 5Group 2 · HS_ – 5 Group 3 · AX_ – 1Group 3 · AX_ – 1 Group 4 · AX_ – 2Group 4 · AX_ – 2
RDS data file (.gzd) 
[Gözlem]
Tarih=17.07.2026
Saat=07:50
Gözlemci=Melike ERYILMAZ
KontrolEden=Burçin TANIK
Durumaçısı=4.62
Enlemaçısı=4.52
Boylamaçısı=214.33
Boylamfark=2
GKalite=3
GDurum=K.T
Kuzeyaçısı=-0.3
Sırano=20514
AyRasatNo=14
RasatÖnceki=15.07.2026
RasatSonraki=18.07.2026

[Leke Grupları]
Grupsayısı=4:1:3
LekeSayısı=9:1:8
RölatifSayı=49:11:38
01=AX_ 01 +15.154 -14.344 199.986 -1.000 0000 0 +15.154 -14.344 +15.154 -14.344
02=HS_ 05 -05.696 -22.398 191.932 +0.000 0000 0 -03.232 -20.928 -08.160 -23.868 -05.696 -21.428 -05.696 -23.368
03=AX_ 01 -09.228 -29.840 184.490 -1.000 0000 0 -09.228 -29.840 -09.228 -29.840
04=AX_ 02 -10.866 -58.882 155.448 +0.000 0000 0 -10.139 -57.924 -11.592 -59.840 -10.866 -58.424 -10.866 -59.340
20260717.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 →

2026/20260717_me · ME · 6 frames · 128.6 MB · 08:07:50–08:10:20 UT

08:08:20 UT · 30 ms 08:09:20 UT · 30 ms 08:10:20 UT · 30 ms 08:08:50 UT · 60 ms · over-exposed 08:07:50 UT · 60 ms · over-exposed 08:09:50 UT · 60 ms · over-exposed

Coronado H-α animations from frame sequences

No Coronado observation for this day.