Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Sunday, 17 May 2026

‹ 16.05.2026 2026 18.05.2026 ›

Photosphere sunspot drawing and RDS evaluation

17.05.2026 photosphere drawing

High-resolution scan (3224 px)

Time
09:15 UT
Observer
Burçin TANIK
g
7
f
22
R
92
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · AX_ – 2Group 1 · AX_ – 2 Group 2 · DAO – 4Group 2 · DAO – 4 Group 3 · DAO – 9Group 3 · DAO – 9 Group 4 · HA_ – 2Group 4 · HA_ – 2 Group 5 · HA_ – 2Group 5 · HA_ – 2 Group 6 · AX_ – 2Group 6 · AX_ – 2 Group 7 · AX_ – 1Group 7 · AX_ – 1
RDS data file (.gzd) 
[Gözlem]
Tarih=17.05.2026
Saat=09:15
Gözlemci=Burçin TANIK
KontrolEden=Emre YILMAN
Durumaçısı=-20.29
Enlemaçısı=-2.43
Boylamaçısı=300.83
Boylamfark=2
GKalite=3
GDurum=G.T
Kuzeyaçısı=-0.6
Sırano=20468
AyRasatNo=10
RasatÖnceki=16.05.2026
RasatSonraki=18.05.2026

[Leke Grupları]
Grupsayısı=7:5:2
LekeSayısı=22:19:3
RölatifSayı=92:69:23
01=AX_ 02 +19.686 +73.771 014.601 +0.000 0000 0 +20.159 +74.459 +19.214 +73.840 +19.686 +73.581 +19.686 +73.962
02=DAO 04 +18.419 +27.484 328.314 +0.000 0000 0 +19.531 +29.538 +17.307 +25.430 +18.419 +29.338 +18.419 +25.630
03=DAO 09 +07.390 -22.248 278.582 +0.000 0000 0 +08.105 -19.533 +05.973 -24.964 +07.390 -19.733 +07.390 -24.764
04=HA_ 02 +04.339 -61.973 238.857 +0.000 0000 0 +05.215 -61.400 +03.463 -62.906 +04.339 -61.720 +04.339 -62.226
05=HA_ 02 +14.519 -63.997 236.833 +0.000 0000 0 +15.243 -62.914 +13.796 -65.810 +14.519 -63.490 +14.519 -64.945
06=AX_ 02 -16.530 -52.930 248.737 +0.000 0000 0 -15.533 -50.879 -16.573 -53.307 -16.530 -52.216 -16.530 -53.644
07=AX_ 01 -15.940 -68.248 232.582 -1.000 0000 0 -15.940 -68.248 -15.940 -68.248
20260517.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 →

2026/20260517_bto · BTO · 4 frames · 85.7 MB · 09:32:58–09:40:41 UT

09:40:41 UT · 20 ms 09:32:58 UT · 30 ms 09:37:03 UT · 60 ms · over-exposed 09:38:57 UT · 50 ms · over-exposed

Coronado H-α animations from frame sequences

No Coronado observation for this day.