Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Solar Images Wednesday, 20 August 2025

‹ 19.08.2025 2025 21.08.2025 ›

Photosphere sunspot drawing and RDS evaluation

20.08.2025 photosphere drawing

High-resolution scan (3231 px)

Time
10:00 UT
Observer
Ergün EGE
g
6
f
12
R
72
Seeing
3 / 5

Sunspot groups and observation details →

Sunspot groups (from the drawing)

Group 1 · AX_ – 1Group 1 · AX_ – 1 Group 2 · BXO – 2Group 2 · BXO – 2 Group 3 · AX_ – 1Group 3 · AX_ – 1 Group 4 · HS_ – 1Group 4 · HS_ – 1 Group 5 · DAC – 6Group 5 · DAC – 6 Group 6 · HS_ – 1Group 6 · HS_ – 1
RDS data file (.gzd) 
[Gözlem]
Tarih=20.08.2025
Saat=10:00
Gözlemci=Ergün EGE
KontrolEden=Burçin TANIK
Durumaçısı=17.81
Enlemaçısı=6.87
Boylamaçısı=261.05
Boylamfark=1
GKalite=3
GDurum=
Kuzeyaçısı=-0.5
Sırano=20327
AyRasatNo=15
RasatÖnceki=19.08.2025
RasatSonraki=21.08.2025

[Leke Grupları]
Grupsayısı=6:4:2
LekeSayısı=12:5:7
RölatifSayı=72:45:27
01=AX_ 01 +09.496 +13.735 274.785 +0.000 0000 0 +09.733 +13.950 +09.259 +13.519 +09.496 +13.450 +09.496 +14.190
02=BXO 02 +07.535 -41.240 219.810 +0.000 0000 0 +07.832 -39.651 +07.239 -42.828 +07.535 -40.152 +07.535 -42.329
03=AX_ 01 +18.210 -65.105 195.945 +0.000 0000 0 +18.299 -64.530 +17.742 -65.680 +18.210 -65.300 +18.210 -65.180
04=HS_ 01 +10.224 -85.745 175.305 +0.000 0000 0 +11.939 -83.740 +08.510 -87.750 +10.224 -84.240 +10.224 -87.250
05=DAC 06 -17.989 -03.422 257.628 +0.000 0000 0 -17.311 -00.903 -18.667 -05.940 -17.989 -01.403 -17.989 -05.441
06=HS_ 01 -08.404 -52.119 208.931 +0.000 0000 0 -07.840 -51.270 -08.967 -52.967 -08.404 -51.771 -08.404 -52.467
20250820.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 →

2025/20250820 · · 8 frames · 171.4 MB · 10:05:10–10:24:20 UT

10:22:15 UT · 40 ms 10:10:11 UT · 50 ms · over-exposed 10:22:51 UT · 50 ms · over-exposed 10:05:10 UT · 40 ms 10:20:33 UT · 60 ms · over-exposed 10:23:27 UT · 60 ms · over-exposed 10:24:20 UT · 70 ms · over-exposed 10:21:38 UT · 70 ms · over-exposed

Coronado H-α animations from frame sequences

No Coronado observation for this day.