Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Saturday, 18 July 2026

‹ 17.07.2026 2026 19.07.2026 ›

Photosphere sunspot drawing and RDS evaluation

18.07.2026 photosphere drawing

High-resolution scan (3227 px)

Time
11:30 UT
Observer
Burçin TANIK
g
3
f
4
R
34
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · HK_ – 2Group 1 · HK_ – 2 Group 2 · AX_ – 1Group 2 · AX_ – 1 Group 3 · AX_ – 1Group 3 · AX_ – 1
RDS data file (.gzd) 
[Gözlem]
Tarih=18.07.2026
Saat=11:30
Gözlemci=Burçin TANIK
KontrolEden=Olcay PLEVNE
Durumaçısı=5.13
Enlemaçısı=4.63
Boylamaçısı=199.07
Boylamfark=0
GKalite=3
GDurum=G.T
Kuzeyaçısı=-0.6
Sırano=20515
AyRasatNo=15
RasatÖnceki=17.07.2026
RasatSonraki=19.07.2026

[Leke Grupları]
Grupsayısı=3:0:3
LekeSayısı=4:0:4
RölatifSayı=34:0:34
01=HK_ 02 -05.870 -06.238 192.832 +0.000 0000 0 -04.580 -05.179 -07.159 -07.296 -05.870 -05.679 -05.870 -06.797
02=AX_ 01 -07.135 -07.649 191.421 -1.000 0000 0 -07.135 -07.649 -07.135 -07.649
03=AX_ 01 -10.761 -41.521 157.549 -1.000 0000 0 -10.761 -41.521 -10.761 -41.521
20260718.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 →

2026/20260718_bto · BTO · 3 frames · 64.3 MB · 11:38:07–11:41:53 UT

11:41:53 UT · 20 ms 11:38:07 UT · 30 ms 11:40:19 UT · 60 ms · over-exposed

Coronado H-α animations from frame sequences

No Coronado observation for this day.