Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Tuesday, 18 August 2026

‹ 17.08.2026 2026 20.08.2026 ›

Photosphere sunspot drawing and RDS evaluation

18.08.2026 photosphere drawing

High-resolution scan (3230 px)

Time
07:57 UT
Observer
Melike ERYILMAZ
g
3
f
28
R
58
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · FHC – 9Group 1 · FHC – 9 Group 2 · EKC – 14Group 2 · EKC – 14 Group 3 · CKI – 5Group 3 · CKI – 5
RDS data file (.gzd) 
[Gözlem]
Tarih=18.08.2026
Saat=07:57
Gözlemci=Melike ERYILMAZ
KontrolEden=Melike ERYILMAZ
Durumaçısı=17.06
Enlemaçısı=6.78
Boylamaçısı=151.07
Boylamfark=2
GKalite=3
GDurum=K.T
Kuzeyaçısı=-0.9
Sırano=20544
AyRasatNo=17
RasatÖnceki=17.08.2026
RasatSonraki=20.08.2026

[Leke Grupları]
Grupsayısı=3:3:0
LekeSayısı=28:28:0
RölatifSayı=58:58:0
01=FHC 09 +11.617 +63.882 214.952 +0.000 0000 0 +13.441 +72.360 +09.793 +55.404 +11.617 +72.160 +11.617 +55.604
02=EKC 14 +03.704 +43.405 194.475 +0.000 0000 0 +06.171 +49.638 +01.237 +37.172 +03.704 +49.438 +03.704 +37.372
03=CKI 05 +08.302 +10.602 161.673 +0.000 0000 0 +09.883 +13.814 +06.721 +07.391 +08.302 +13.614 +08.302 +07.591
20260818.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 →

2026/20260818_me · ME · 6 frames · 128.6 MB · 08:04:45–08:07:15 UT

08:07:15 UT · 30 ms 08:05:15 UT · 30 ms 08:06:15 UT · 30 ms 08:06:45 UT · 60 ms · over-exposed 08:05:45 UT · 60 ms · over-exposed 08:04:45 UT · 60 ms · over-exposed

Coronado H-α animations from frame sequences

No Coronado observation for this day.