Istanbul University Faculty of Science

SOLAR OBSERVATIONS

Istanbul University Observatory · Sunspot observations since 1950

Observatory

Sunspot Records 1950–2007

13,360 / 15,663 sheets usable

Years usable / all sheets

19502 / 9 1951253 / 266 1952270 / 291 1953287 / 303 1954286 / 292 1955284 / 299 1956270 / 299 1957262 / 299 1958264 / 307 1959231 / 280 1960235 / 271 1961233 / 261 1962210 / 254 1963194 / 258 1964246 / 274 1965245 / 280 1966224 / 261 1967244 / 297 1968241 / 278 1969224 / 266 1970262 / 291 1971274 / 283 1972231 / 251 1973263 / 303 1974279 / 292 1975280 / 302 1976257 / 287 1977246 / 275 1978239 / 271 1979209 / 285 1980207 / 256 1981248 / 288 1982254 / 301 1983229 / 295 1984260 / 290 1985271 / 292 1986262 / 278 1987221 / 254 1988215 / 272 1989187 / 209 1990168 / 293 1991217 / 252 1992222 / 273 1993241 / 265 1994257 / 283 1995266 / 275 1996111 / 235 1997218 / 237 1998211 / 248 1999181 / 265 2000173 / 272 2001203 / 276 200282 / 279 2003239 / 252 2004266 / 280 2005216 / 236 2006221 / 238 2007269 / 284

Sheets of 1973 303 sheets · 263 usable · mean R 50.4

DrawingDategfRReading
01.01.1973 21232 counts consistent, some coordinates doubtful
02.01.1973 31040 all checks consistent
03.01.1973 43070 counts consistent, some coordinates doubtful
09.01.1973 733103 all checks consistent
12.01.1973 2525 all checks consistent
13.01.1973 1313 all checks consistent
15.01.1973 2424 all checks consistent
16.01.1973 1313 all checks consistent
17.01.1973 1212 all checks consistent
19.01.1973 41151 all checks consistent
24.01.1973 3434 counts consistent, some coordinates doubtful
25.01.1973 2323 all checks consistent
28.01.1973 2222 all checks consistent
31.01.1973 1111 all checks consistent
01.02.1973 2222 all checks consistent
03.02.1973 1616 all checks consistent
05.02.1973 3636 counts consistent, some coordinates doubtful
06.02.1973 ——— reading could not be verified
07.02.1973 3535 all checks consistent
08.02.1973 2424 all checks consistent
09.02.1973 41252 all checks consistent
10.02.1973 5959 all checks consistent
11.02.1973 62181 all checks consistent
14.02.1973 ——— reading could not be verified
15.02.1973 734104 counts consistent, some coordinates doubtful
16.02.1973 828108 all checks consistent
18.02.1973 31343 counts consistent, some coordinates doubtful
19.02.1973 1616 all checks consistent
20.02.1973 41555 all checks consistent
22.02.1973 31040 all checks consistent
25.02.1973 41656 all checks consistent
26.02.1973 31949 all checks consistent
01.03.1973 33969 all checks consistent
02.03.1973 34979 all checks consistent
03.03.1973 3939 all checks consistent
04.03.1973 ——— reading could not be verified
05.03.1973 ——— reading could not be verified
06.03.1973 21131 all checks consistent
07.03.1973 41858 all checks consistent
08.03.1973 ——— reading could not be verified
09.03.1973 42969 all checks consistent
10.03.1973 ——— reading could not be verified
12.03.1973 576126 all checks consistent
13.03.1973 44787 all checks consistent
14.03.1973 44585 all checks consistent
19.03.1973 ——— reading could not be verified
21.03.1973 11424 all checks consistent
22.03.1973 22545 all checks consistent
23.03.1973 32151 all checks consistent
24.03.1973 21737 all checks consistent
25.03.1973 21636 all checks consistent
26.03.1973 21131 all checks consistent
27.03.1973 31242 counts consistent, some coordinates doubtful
28.03.1973 31242 all checks consistent
29.03.1973 32656 all checks consistent
30.03.1973 33969 all checks consistent
31.03.1973 43070 all checks consistent
01.04.1973 44686 all checks consistent
02.04.1973 45898 all checks consistent
03.04.1973 687147 all checks consistent
04.04.1973 52979 all checks consistent
05.04.1973 53989 all checks consistent
08.04.1973 749119 all checks consistent
09.04.1973 784154 all checks consistent
10.04.1973 681141 counts consistent, some coordinates doubtful
12.04.1973 22343 all checks consistent
13.04.1973 24262 all checks consistent
14.04.1973 12737 all checks consistent
15.04.1973 22141 all checks consistent
16.04.1973 31242 all checks consistent
17.04.1973 1212 all checks consistent
18.04.1973 1414 all checks consistent
20.04.1973 22949 all checks consistent
21.04.1973 23151 all checks consistent
22.04.1973 34272 counts consistent, some coordinates doubtful
23.04.1973 562112 counts consistent, some coordinates doubtful
24.04.1973 45292 all checks consistent
25.04.1973 44282 all checks consistent
28.04.1973 43777 all checks consistent
29.04.1973 32252 all checks consistent
30.04.1973 62484 all checks consistent
01.05.1973 3838 all checks consistent
02.05.1973 31545 all checks consistent
03.05.1973 32656 all checks consistent
04.05.1973 54090 counts consistent, some coordinates doubtful
05.05.1973 44181 all checks consistent
06.05.1973 ——— reading could not be verified
07.05.1973 482122 all checks consistent
08.05.1973 27797 counts consistent, some coordinates doubtful
09.05.1973 ——— reading could not be verified
10.05.1973 22141 all checks consistent
11.05.1973 ——— reading could not be verified
12.05.1973 ——— reading could not be verified
13.05.1973 ——— reading could not be verified
14.05.1973 1111 all checks consistent
15.05.1973 31040 all checks consistent
16.05.1973 31444 all checks consistent
17.05.1973 32656 all checks consistent
18.05.1973 42060 all checks consistent
19.05.1973 32151 all checks consistent
20.05.1973 53383 all checks consistent
21.05.1973 33767 all checks consistent
22.05.1973 54898 all checks consistent
23.05.1973 42464 all checks consistent
24.05.1973 54191 all checks consistent
25.05.1973 ——— reading could not be verified
26.05.1973 31545 all checks consistent
27.05.1973 52171 all checks consistent
28.05.1973 ——— reading could not be verified
29.05.1973 ——— reading could not be verified
30.05.1973 ——— reading could not be verified
31.05.1973 3838 all checks consistent
01.06.1973 1414 all checks consistent
02.06.1973 1111 all checks consistent
03.06.1973 1515 all checks consistent
04.06.1973 2626 all checks consistent
05.06.1973 000 all checks consistent
06.06.1973 2929 all checks consistent
07.06.1973 41151 all checks consistent
08.06.1973 ——— reading could not be verified
09.06.1973 21232 all checks consistent
10.06.1973 41353 all checks consistent
12.06.1973 63999 all checks consistent
13.06.1973 44585 all checks consistent
14.06.1973 52878 counts consistent, some coordinates doubtful
15.06.1973 43474 all checks consistent
16.06.1973 ——— reading could not be verified
17.06.1973 ——— reading could not be verified
18.06.1973 22949 all checks consistent
19.06.1973 42767 all checks consistent
20.06.1973 42565 all checks consistent
21.06.1973 ——— reading could not be verified
22.06.1973 ——— reading could not be verified
23.06.1973 33565 all checks consistent
24.06.1973 34676 all checks consistent
25.06.1973 ——— reading could not be verified
26.06.1973 34878 all checks consistent
27.06.1973 32858 all checks consistent
28.06.1973 42161 all checks consistent
29.06.1973 62181 counts consistent, some coordinates doubtful
30.06.1973 31040 all checks consistent
01.07.1973 21232 all checks consistent
02.07.1973 31949 all checks consistent
03.07.1973 32757 all checks consistent
04.07.1973 21535 counts consistent, some coordinates doubtful
05.07.1973 22646 all checks consistent
06.07.1973 34979 all checks consistent
07.07.1973 43272 all checks consistent
08.07.1973 32858 all checks consistent
09.07.1973 22646 all checks consistent
10.07.1973 22242 all checks consistent
11.07.1973 2828 all checks consistent
12.07.1973 1111 all checks consistent
13.07.1973 1212 all checks consistent
14.07.1973 1313 all checks consistent
15.07.1973 1616 all checks consistent
16.07.1973 2525 all checks consistent
17.07.1973 ——— reading could not be verified
18.07.1973 41656 all checks consistent
19.07.1973 3939 all checks consistent
20.07.1973 ——— reading could not be verified
21.07.1973 1414 all checks consistent
22.07.1973 2424 all checks consistent
23.07.1973 000 all checks consistent
24.07.1973 1717 all checks consistent
25.07.1973 2323 all checks consistent
26.07.1973 1111 all checks consistent
27.07.1973 1111 all checks consistent
28.07.1973 1212 all checks consistent
29.07.1973 2424 all checks consistent
30.07.1973 21131 all checks consistent
31.07.1973 21737 all checks consistent
01.08.1973 41050 all checks consistent
02.08.1973 2626 all checks consistent
03.08.1973 2525 all checks consistent
04.08.1973 31343 all checks consistent
05.08.1973 31747 all checks consistent
06.08.1973 ——— reading could not be verified
07.08.1973 32252 all checks consistent
08.08.1973 32252 all checks consistent
09.08.1973 41959 all checks consistent
10.08.1973 31141 all checks consistent
11.08.1973 3333 all checks consistent
12.08.1973 ——— reading could not be verified
13.08.1973 000 all checks consistent
14.08.1973 000 all checks consistent
15.08.1973 ——— reading could not be verified
16.08.1973 000 all checks consistent
17.08.1973 000 all checks consistent
18.08.1973 ——— reading could not be verified
19.08.1973 1212 all checks consistent
20.08.1973 1212 all checks consistent
21.08.1973 21131 all checks consistent
22.08.1973 1818 all checks consistent
23.08.1973 1515 all checks consistent
24.08.1973 3636 all checks consistent
25.08.1973 31141 all checks consistent
26.08.1973 31343 all checks consistent
27.08.1973 41959 all checks consistent
28.08.1973 32353 all checks consistent
29.08.1973 42767 all checks consistent
30.08.1973 ——— reading could not be verified
31.08.1973 734104 all checks consistent
01.09.1973 955145 counts consistent, some coordinates doubtful
02.09.1973 ——— reading could not be verified
03.09.1973 9101191 all checks consistent
04.09.1973 ——— reading could not be verified
05.09.1973 765135 all checks consistent
06.09.1973 647107 all checks consistent
07.09.1973 557107 all checks consistent
08.09.1973 556106 all checks consistent
09.09.1973 753123 all checks consistent
10.09.1973 45191 all checks consistent
11.09.1973 33565 all checks consistent
12.09.1973 31040 all checks consistent
13.09.1973 ——— reading could not be verified
14.09.1973 2222 all checks consistent
15.09.1973 1111 all checks consistent
16.09.1973 41050 all checks consistent
17.09.1973 2727 all checks consistent
18.09.1973 21131 all checks consistent
19.09.1973 1212 all checks consistent
20.09.1973 41050 all checks consistent
21.09.1973 61777 all checks consistent
22.09.1973 72292 all checks consistent
23.09.1973 53282 all checks consistent
24.09.1973 52676 all checks consistent
25.09.1973 840120 counts consistent, some coordinates doubtful
26.09.1973 62989 all checks consistent
27.09.1973 834114 all checks consistent
28.09.1973 740110 all checks consistent
29.09.1973 944134 all checks consistent
30.09.1973 756126 counts consistent, some coordinates doubtful
01.10.1973 ——— reading could not be verified
02.10.1973 827107 all checks consistent
03.10.1973 53585 counts consistent, some coordinates doubtful
04.10.1973 42666 counts consistent, some coordinates doubtful
05.10.1973 41151 all checks consistent
07.10.1973 ——— reading could not be verified
08.10.1973 3434 counts consistent, some coordinates doubtful
09.10.1973 3939 all checks consistent
10.10.1973 1212 all checks consistent
11.10.1973 000 all checks consistent
12.10.1973 000 all checks consistent
13.10.1973 1414 all checks consistent
14.10.1973 2525 all checks consistent
15.10.1973 1414 all checks consistent
16.10.1973 3939 all checks consistent
17.10.1973 2828 all checks consistent
18.10.1973 2424 all checks consistent
19.10.1973 000 all checks consistent
20.10.1973 000 all checks consistent
21.10.1973 000 all checks consistent
22.10.1973 2424 all checks consistent
26.10.1973 53383 all checks consistent
27.10.1973 44282 all checks consistent
28.10.1973 54191 all checks consistent
29.10.1973 62787 all checks consistent
30.10.1973 62585 all checks consistent
31.10.1973 51363 all checks consistent
01.11.1973 3636 all checks consistent
02.11.1973 3939 all checks consistent
03.11.1973 3838 all checks consistent
04.11.1973 ——— reading could not be verified
05.11.1973 1111 all checks consistent
06.11.1973 000 all checks consistent
07.11.1973 000 all checks consistent
09.11.1973 000 all checks consistent
14.11.1973 1515 all checks consistent
16.11.1973 1919 all checks consistent
17.11.1973 11727 all checks consistent
18.11.1973 2828 all checks consistent
19.11.1973 ——— reading could not be verified
20.11.1973 3737 counts consistent, some coordinates doubtful
21.11.1973 2525 all checks consistent
22.11.1973 31747 counts consistent, some coordinates doubtful
23.11.1973 23151 all checks consistent
24.11.1973 33161 all checks consistent
25.11.1973 33565 all checks consistent
26.11.1973 ——— reading could not be verified
30.11.1973 45595 all checks consistent
01.12.1973 ——— reading could not be verified
04.12.1973 000 all checks consistent
06.12.1973 000 all checks consistent
07.12.1973 000 all checks consistent
08.12.1973 1111 all checks consistent
09.12.1973 1111 all checks consistent
13.12.1973 1212 all checks consistent
14.12.1973 1313 all checks consistent
15.12.1973 1111 all checks consistent
17.12.1973 31141 counts consistent, some coordinates doubtful
18.12.1973 41454 counts consistent, some coordinates doubtful
20.12.1973 22545 all checks consistent
21.12.1973 32858 counts consistent, some coordinates doubtful
22.12.1973 32252 all checks consistent
23.12.1973 42666 all checks consistent
24.12.1973 43070 all checks consistent
25.12.1973 43070 all checks consistent
26.12.1973 31141 all checks consistent
27.12.1973 2323 all checks consistent
28.12.1973 ——— reading could not be verified
29.12.1973 ——— reading could not be verified
31.12.1973 000 all checks consistent

Click a date for the group table and the drawing. “—”: the reading of the sheet could not be verified, numbers are not shown; see the drawing.