ϑ҈ꗗ (List of Observers) - 2021-22 Apparition
| Observer | Location | Telescope | Days | | Disks | Maps | Animations | Others | Measurements |
| Akutsu, Tomio | Ibaraki, Japan | 45cm Refl./35cm SC | 61 | | 460 | | | | | 4 | 209 |
| Akutsu, Hiroaki | Hokkaido, Japan | 28cm Refl. | 6 | | 32 | | | | | | | 75 |
| Asada, Hideto | Kyoto, Japan | 31cm Refl. | 35 | | 89 | | | | | | | | |
| Adachi, Makoto | Shiga, Japan | 36cm/60cm Refl./20cm SC | 113 | * | 322 | | | | | | | | |
| Ishibashi, Tsutomu | Kanagawa, Japan | 31cm/10cm Refl. | 100 | | 262 | | | | | | | 1212 |
| Ito, Satoshi | Aichi, Japan | 30cm/25cm Refl. | 115 | | 211 | | | | | | | 1762 |
| Einaga, Hideo | Hyogo, Japan | 30cm Refl. | 4 | | 6 | 1 | | | | | 98 |
| Ohsugi, Tadao | Ishikawa, Japan | 30cm Refl. | 27 | | 28 | | | | | | | 262 |
| Ota, Satoshi | Okinawa, Japan | 30cm Refl. | 22 | | 45 | | | | | | | 467 |
| Okamura, Osamu | Hyogo, Japan | 28cm SC | 16 | | 45 | | | | | | | 92 |
| Ozaki, Kimikazu | Aichi, Japan | 44cm Refl. | 93 | | 561 | | | | | | | 60 |
| Oyamada, Hiroyuki | Tokyo, Japan | 28cm SC/20cm Refl. | 30 | | 76 | | | | | | | 26 |
| Kanno, Seiichi | Yamagata, Japan | 30cm Refl. | 17 | | 109 | | | | | | | 12 |
| Kumamori, Teruaki | Osaka, Japan | 35cm SC | 95 | | 150 | | | | | | | 2133 |
| Suzuki, Kunihiko | Kanagawa, Japan | 19cm Refl. | 164 | | 356 | | | 1 | | | 3270 |
| Suzuki, Takashi | Tokyo, Japan | 18cm MC | 24 | | 36 | | | | | | | | |
| Nakai, Kenji | Hiroshima, Japan | 28cm SC | 5 | | 7 | | | | | | | | |
| Hatanaka, Akitoshi | Mie, Japan | 40cm Refl. | 10 | | 23 | | | | | 1 | 26 |
| Hirabayashi, Isamu | Tokyo, Japan | 25cm Refl. | 1 | | 2 | | | | | | | | |
| Horiuchi, Tadashi | Kyoto, Japan | 40cm Refl. | 12 | | 24 | | | | | | | 188 |
| Horikawa, Kuniaki | Kanagawa, Japan | 30cm Refl. | 166 | * | 309 | | | | | | | 1029 |
| Mishina, Toshiro | Kanagawa, Japan | 20cm Refl. | 38 | | 95 | | | | | | | | |
| Miyazaki, Isao | Okinawa, Japan | 40cm Refl. | 211 | | 1440 | | | | | | | 9004 |
| Yoneyama, Seiichi | Kanagawa, Japan | 32cm/25cm Refl. | 40 | | 158 | | | | | | | | |
| Abel, Paul | UK | 31cm Refl. | 11 | * | 13 | | | | | | | | |
| Carvalho, Fabio | Brazil | 40cm Refl. | 3 | | 4 | | | | | | | 84 |
| Delcroix, Marc | France | 32cm Refl. | 11 | | 33 | | | 2 | | | 110 |
| Fattinnanzi, Cristian | Italy | 36cm Refl. | 2 | | 3 | | | | | | | 101 |
| Foster, Clyde | South Africa | 35cm SC | 159 | | 597 | | | 2 | | | 4592 |
| Go, Christopher | Philippines | 35cm SC | 65 | | 251 | | | 1 | | | 2015 |
| Lamy, George | USA | 35cm SC | 7 | | 10 | | | | | | | 249 |
| Olivetti, Tiziano | Thailand | 50cm Refl. | 26 | | 82 | | | | | | | 1075 |
| Pellier, Christophe | France | 31cm/25cm Refl. | 17 | | 101 | 6 | | | 1 | 118 |
| Wesley, Anthony | Australia | 33cm Refl. | 19 | | 24 | | | 2 | | | 255 |
| Total | | | | | 5964 | 7 | 8 | 6 | 28524 |
|
| * | visual observation |