Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Monthly Sunspot Classification and Coordinates

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September 2025 Monthly report →

Each group: class – number of spots (B, ΔL). NS: No sunspot.

DrawingDayRClassification and Coordinates
02 159 AX_ – 1 (18, 86.3W), AX_ – 1 (10, 86.3W), AX_ – 2 (19, 30.9W), CAI – 6 (5, 25.2W), HS_ – 1 (17, 23.0E), HS_ – 1 (9, 26.3E), FAI – 6 (30, 47.4E), AX_ – 2 (7, 65.2E), EAC – 14 (-19, 40.7W), HS_ – 1 (-21, 26.9W), CAI – 3 (-15, 20.4W), HS_ – 1 (-14, 81.8E)
03 136 CAO – 10 (4, 42.8W), AX_ – 2 (18, 07.9E), HS_ – 1 (9, 10.7E), FAI – 9 (29, 31.3E), DAI – 6 (8, 48.3E), EAI – 14 (-18, 57.7W), HS_ – 1 (-20, 42.3W), CAO – 2 (-15, 36.4W), HS_ – 1 (-14, 63.4E)
04 170 CAI – 10 (4, 54.6W), AX_ – 2 (17, 02.9W), HS_ – 1 (9, 00.6W), AX_ – 2 (11, 17.4E), FAI – 33 (29, 20.3E), DAI – 6 (9, 37.2E), FAC – 11 (-18, 69.6W), HS_ – 1 (-21, 53.8W), DAI – 3 (-15, 46.9W), HS_ – 1 (-14, 53.5E)
05 125 HS_ – 1 (3, 64.4W), HS_ – 1 (9, 12.7W), BXI – 7 (11, 05.4E), FAI – 26 (30, 07.7E), CAI – 13 (8, 24.9E), FAI – 6 (-18, 65.8W), HS_ – 1 (-13, 41.0E)
07 80 HS_ – 1 (9, 40.3W), CAI – 14 (28, 22.5W), DSI – 3 (8, 02.4W), HS_ – 1 (-14, 13.4E), DAI – 11 (-13, 24.5E)
08 112 HS_ – 1 (9, 53.2W), BXI – 5 (10, 37.7W), CAI – 15 (29, 35.2W), HS_ – 1 (8, 18.0W), AX_ – 2 (10, 02.5W), HS_ – 2 (-13, 00.5E), DAI – 16 (-13, 11.2E)
09 89 HS_ – 1 (9, 69.1W), BXO – 2 (10, 51.7W), CSI – 8 (29, 49.6W), CSI – 6 (7, 30.2W), AX_ – 1 (16, 04.4E), FHC – 11 (-14, 06.4W)
10 82 ?__ – 1 (9, 78.6W), HS_ – 1 (28, 65.8W), BXI – 7 (7, 43.4W), AX_ – 1 (25, 19.2W), HS_ – 1 (-13, 26.6W), DSC – 11 (-13, 16.1W)
11 81 CAI – 4 (28, 78.8W), BXI – 8 (7, 55.2W), AX_ – 3 (25, 30.5W), HS_ – 2 (-13, 39.9W), DAI – 14 (-14, 28.2W)
12 55 AX_ – 1 (22, 17.7E), DSC – 5 (11, 72.2E), HH_ – 1 (-14, 53.5W), ESO – 8 (-14, 42.6W)
14 67 BXI – 5 (15, 62.4W), AX_ – 2 (26, 08.6E), DAC – 6 (10, 44.9E), DAI – 3 (-13, 76.6W), HS_ – 1 (-14, 80.8E)
15 73 DHO – 2 (14, 78.8W), CSO – 5 (26, 07.3W), DSC – 10 (11, 31.7E), AX_ – 2 (4, 63.6E), DHO – 4 (-15, 68.5E)
16 128 CAI – 3 (26, 18.0W), DAI – 7 (10, 18.9E), AX_ – 2 (10, 27.2E), AX_ – 3 (13, 32.1E), CAI – 3 (5, 54.0E), BXI – 8 (-17, 24.6E), AX_ – 2 (-10, 55.7E), DAI – 7 (-15, 57.5E), AX_ – 3 (-16, 74.6E)
17 127 AX_ – 1 (26, 35.0W), DSC – 13 (10, 06.4E), AX_ – 1 (14, 17.2E), DHI – 5 (5, 39.1E), HH_ – 1 (11, 77.5E), DSC – 16 (-17, 09.1E), EHO – 5 (-15, 43.3E), CRI – 5 (-15, 59.7E)
18 132 AX_ – 1 (25, 48.7W), DSC – 14 (10, 09.1W), CSI – 2 (5, 22.1E), HH_ – 1 (12, 61.5E), DKC – 20 (-16, 06.7W), HH_ – 5 (-13, 23.7E), BXO – 2 (-16, 33.2E), BXI – 7 (-15, 43.9E)
19 134 HR_ – 2 (26, 60.4W), DSI – 8 (10, 20.3W), CSO – 5 (4, 13.4E), HS_ – 2 (10, 50.8E), DAC – 21 (-18, 17.2W), HA_ – 2 (-15, 14.6E), AX_ – 3 (-17, 23.4E), CRI – 11 (-16, 31.5E)
20 178 CRO – 2 (27, 70.6W), DSC – 7 (12, 33.4W), CSO – 5 (4, 00.7W), CKI – 9 (10, 37.8E), AX_ – 1 (-15, 68.3W), ESC – 19 (-18, 30.4W), CHO – 8 (-13, 00.9E), AX_ – 1 (-17, 10.2E), DSI – 13 (-14, 17.6E), DHO – 2 (-17, 77.0E), HH_ – 1 (-8, 81.0E)
21 202 CSI – 6 (11, 48.8W), AX_ – 1 (15, 38.5W), HS_ – 2 (4, 17.2W), DHI – 7 (10, 22.9E), HH_ – 1 (4, 77.2E), DKC – 16 (-18, 47.2W), AX_ – 2 (-24, 13.3W), CKI – 17 (-15, 12.4W), AX_ – 2 (-19, 02.6W), DSI – 11 (-13, 01.2E), AX_ – 1 (-16, 05.7E), DSO – 2 (-17, 62.8E), DSI – 4 (-9, 67.8E)
22 202 CSO – 2 (12, 63.7W), HS_ – 1 (4, 31.8W), CHI – 6 (11, 08.4E), AX_ – 2 (8, 25.2E), HS_ – 1 (5, 62.5E), EHI – 11 (-17, 62.2W), AX_ – 1 (-23, 28.9W), CKI – 17 (-15, 27.2W), AX_ – 1 (-18, 17.3W), CSO – 3 (-13, 15.9W), AX_ – 3 (-12, 10.3W), AX_ – 5 (-17, 07.8W), DSO – 3 (-17, 47.9E), DSC – 6 (-10, 53.7E)
23 190 HS_ – 1 (11, 73.9W), HS_ – 1 (4, 42.3W), HH_ – 4 (11, 02.2W), BXI – 6 (8, 15.7E), AX_ – 1 (5, 51.0E), EHO – 7 (-19, 72.9W), CHI – 10 (-15, 37.4W), CSO – 8 (-13, 25.1W), CRI – 4 (-4, 21.9W), AX_ – 3 (-17, 18.1W), DSO – 4 (-18, 38.1E), DSI – 9 (-10, 42.9E), DSO – 2 (-11, 70.5E)
24 128 HS_ – 1 (4, 57.9W), CAO – 2 (10, 15.8W), HS_ – 1 (4, 37.2E), CAI – 8 (-15, 51.2W), CAI – 10 (-3, 36.2W), CAI – 8 (-18, 24.3E), DAC – 12 (-10, 29.8E), DSI – 6 (-11, 54.4E)
25 160 HS_ – 1 (4, 69.7W), HH_ – 2 (11, 27.8W), HS_ – 2 (5, 29.7E), CHO – 5 (-16, 63.8W), AX_ – 1 (-23, 63.6W), CSO – 2 (-13, 55.9W), DSI – 4 (-4, 49.6W), CSO – 2 (-7, 39.6W), CRI – 5 (-17, 14.9E), DSC – 12 (-10, 17.5E), HS_ – 1 (-12, 40.6E), CRO – 3 (-15, 49.4E)
30 170 AX_ – 3 (16, 11.2W), AX_ – 3 (11, 08.1W), DAC – 24 (11, 23.1E), CAI – 11 (6, 31.4E), CAI – 8 (19, 32.8E), HS_ – 1 (28, 33.3E), HS_ – 3 (-9, 51.8W), DAC – 37 (-11, 29.3W)