Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Thursday, 31 July 2025

‹ 30.07.2025 2025 01.08.2025 ›

Photosphere sunspot drawing and RDS evaluation

31.07.2025 photosphere drawing

High-resolution scan (3229 px)

Time
07:20 UT
Observer
Ergün EGE
g
11
f
58
R
168
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · HS_ – 1Group 1 · HS_ – 1 Group 2 · CRI – 8Group 2 · CRI – 8 Group 3 · BXI – 10Group 3 · BXI – 10 Group 4 · CSO – 3Group 4 · CSO – 3 Group 5 · DSO – 9Group 5 · DSO – 9 Group 6 · HS_ – 2Group 6 · HS_ – 2 Group 7 · HA_ – 2Group 7 · HA_ – 2 Group 8 · CRI – 15Group 8 · CRI – 15 Group 9 · HS_ – 1Group 9 · HS_ – 1 Group 10 · AX_ – 1Group 10 · AX_ – 1
RDS data file (.gzd) 
[Gözlem]
Tarih=31.07.2025
Saat=07:20
Gözlemci=Ergün EGE
KontrolEden=Burçin TANIK
Durumaçısı=10.6
Enlemaçısı=5.73
Boylamaçısı=166.94
Boylamfark=3
GKalite=3
GDurum=B.A
Kuzeyaçısı=-0.4
Sırano=20312
AyRasatNo=25
RasatÖnceki=30.07.2025
RasatSonraki=01.08.2025

[Leke Grupları]
Grupsayısı=11:4:7
LekeSayısı=58:22:36
RölatifSayı=168:62:106
01=HS_ 01 +15.789 +80.539 247.479 -1.000 0000 0 +16.641 +82.368 +14.937 +78.711
02=CRI 08 +23.796 +27.629 194.569 +0.000 0000 0 +24.875 +30.242 +22.717 +25.150 +23.796 +30.420 +23.796 +25.215
03=BXI 10 +10.570 -01.421 165.519 +0.000 0000 0 +11.290 +00.657 +08.823 -03.500 +10.570 +00.457 +10.570 -03.300
04=CSO 03 +12.607 -68.784 098.156 +0.000 0000 0 +14.900 -65.534 +11.124 -72.340 +12.607 -65.734 +12.607 -71.834
05=DSO 09 -28.787 +47.632 214.572 +0.000 0000 0 -27.630 +54.820 -30.511 +41.182 -28.787 +53.882 -28.787 +41.382
06=HS_ 02 -13.460 +38.420 205.360 -1.000 0000 0 -12.330 +39.718 -14.590 +37.123
07=HA_ 02 -19.946 +28.219 195.159 -1.000 0000 0 -19.226 +29.120 -20.667 +27.426
08=CRI 15 -10.121 +24.439 191.379 +0.000 0000 0 -07.456 +29.403 -12.786 +19.476 -10.121 +29.203 -10.121 +19.676
09=HS_ 01 -12.402 -30.855 136.850 -1.000 0000 0 -11.620 -29.898 -13.184 -31.811
10=AX_ 01 -17.712 -33.170 133.770 +0.000 0000 0 -17.338 -32.943 -18.850 -33.397 -17.712 -33.443 -17.712 -32.897
11=DRO 06 -12.104 -38.276 128.664 -1.000 0000 0 -11.466 -33.776 -12.743 -42.775
20250731.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 →

2025/20250731 · · 8 frames · 171.4 MB · 07:28:11–07:44:55 UT

07:38:19 UT · 40 ms 07:28:11 UT · 40 ms 07:43:35 UT · 50 ms 07:31:26 UT · 50 ms · over-exposed 07:44:20 UT · 60 ms · over-exposed 07:44:55 UT · 70 ms · over-exposed 07:36:16 UT · 60 ms · over-exposed 07:37:41 UT · 70 ms · over-exposed

Coronado H-α animations from frame sequences

No Coronado observation for this day.