Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Tuesday, 22 April 2025

‹ 21.04.2025 2025 23.04.2025 ›

Photosphere sunspot drawing and RDS evaluation

22.04.2025 photosphere drawing

High-resolution scan (3218 px)

Time
11:00 UT
Observer
Olcay PLEVNE
g
6
f
39
R
99
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · DAI – 13Group 1 · DAI – 13 Group 2 · BXI – 2Group 2 · BXI – 2 Group 3 · DAI – 11Group 3 · DAI – 11 Group 4 · CSI – 6Group 4 · CSI – 6 Group 5 · BXI – 4Group 5 · BXI – 4 Group 6 · HS_ – 3Group 6 · HS_ – 3
RDS data file (.gzd) 
[Gözlem]
Tarih=22.04.2025
Saat=11:00
Gözlemci=Olcay PLEVNE
KontrolEden=Burçin TANIK
Durumaçısı=-25.34
Enlemaçısı=-4.99
Boylamaçısı=47.88
Boylamfark=1
GKalite=3
GDurum=K.T
Kuzeyaçısı=0.0
Sırano=20229
AyRasatNo=13
RasatÖnceki=21.04.2025
RasatSonraki=23.04.2025

[Leke Grupları]
Grupsayısı=6:1:5
LekeSayısı=39:13:26
RölatifSayı=99:23:76
01=DAI 13 +11.110 -03.747 044.133 +0.000 0000 0 +12.948 +02.200 +09.740 -09.513 +11.110 +01.820 +11.110 -09.313
02=BXI 02 -13.842 +54.601 102.481 +0.000 0000 0 -11.992 +55.164 -15.693 +54.370 -13.842 +54.498 -13.842 +54.704
03=DAI 11 -02.434 +21.566 069.446 +0.000 0000 0 +00.222 +24.000 -05.900 +19.133 -02.434 +23.800 -02.434 +19.333
04=CSI 06 -07.857 -18.508 029.372 +0.000 0000 0 -06.616 -15.711 -09.980 -21.306 -07.857 -15.911 -07.857 -21.106
05=BXI 04 -12.830 -48.518 359.362 +0.000 0000 0 -11.236 -46.286 -12.929 -50.750 -12.830 -46.486 -12.830 -50.550
06=HS_ 03 -25.159 -57.843 350.370 +0.000 0000 0 -23.917 -55.449 -26.400 -60.237 -25.159 -55.949 -25.159 -59.737
20250422.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 →

2025/20250422_op · OP · 4 frames · 85.7 MB · 11:20:41–11:23:51 UT

11:22:23 UT · 30 ms 11:20:41 UT · 30 ms 11:23:51 UT · 60 ms · over-exposed 11:23:05 UT · 60 ms · over-exposed

Coronado H-α animations from frame sequences

No Coronado observation for this day.