C/2021 S3 (PANSTARRS)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2021 S3 (PANSTARRS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2024-02-14T17:02:56.019840Z |
| Orbit solution date (soln_date, UTC) | 2026-07-28T14:12:16Z |
| Obs used | 4867 |
| NEO | - |
| M1 | 10.700 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2021-09-24T13:27:42.969600Z |
| Discovery magnitude (MPC) | 20.17 i |
| Discovery observatory (MPC) | F52 · Pan-STARRS 2, Haleakala |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2024-03-19.0000000 |
| e | 1.00024547 |
| q (au) | 1.320205 |
| a (au) | -5378.325711 |
| i (deg) | 58.532818 |
| Ω (om, deg) | 215.620806 |
| ω (w, deg) | 6.853898 |
| M (ma, deg) | 0.000083 |
等級
散乱 + 全体線形
$$ M_a = (9.812 + 3.233\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 9.812 |
| n | 3.233 |
| gf | 0.991 |
| gb | -0.915 |
| k | 0.980 |
| δ90 | 9.884 |
| パラメータ | 記号 | 範囲 | 説明 |
|---|---|---|---|
| 太陽・地球距離が1 AUのときの絶対等級 | H0 | -5 to 20 | 彗星の固有の明るさ |
| 測光スロープパラメータ | n | 2 to 6 | 太陽距離に対する明るさ変化率 |
| 前方散乱非対称係数 | gf |
0.8 to 1 | 前方散乱の強さ |
| 後方散乱非対称係数 | gb |
-1 to -0.5 | 後方散乱の強さ |
| 分配係数 | k | 0.8 to 1 | 前方/後方散乱の寄与比 |
| ダスト/ガス明るさ比 | δ90 | 1 to 10 | ダスト散乱とガス放射の相対寄与 |
参考: EPSC-DPS2025-160
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) | 終了日 (UTC) | a | b |
|---|---|---|---|
| 2020-12-06 | 2023-05-02 | +6.6906 | -5.821 |
| 2023-05-02 | 2024-02-14 | -0.5527 | -1.219 |
| 2024-02-14 | 2024-11-13 | +1.6110 | -0.826 |
| 2024-11-13 | 2025-12-27 | +6.1193 | -3.554 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
ファインディングチャート
天体暦
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 23:58:03.87 | +37:27:41.1 | HIP 118297 | 27.76 |
| 2026-09-20 12:00 | 23:57:50.82 | +37:26:19.8 | HIP 118297 | 30.53 |
| 2026-09-21 00:00 | 23:57:37.77 | +37:24:57.3 | HIP 118297 | 33.34 |
| 2026-09-21 12:00 | 23:57:24.74 | +37:23:33.7 | HIP 117890 | 33.34 |
| 2026-09-22 00:00 | 23:57:11.71 | +37:22:09.0 | HIP 117890 | 31.53 |
| 2026-09-22 12:00 | 23:56:58.70 | +37:20:43.1 | HIP 117890 | 29.92 |
| 2026-09-23 00:00 | 23:56:45.70 | +37:19:16.1 | HIP 117890 | 28.52 |
| 2026-09-23 12:00 | 23:56:32.72 | +37:17:48.1 | HIP 117890 | 27.39 |
| 2026-09-24 00:00 | 23:56:19.76 | +37:16:18.9 | HIP 117890 | 26.56 |
| 2026-09-24 12:00 | 23:56:06.81 | +37:14:48.6 | HIP 117890 | 26.06 |
| 2026-09-25 00:00 | 23:55:53.88 | +37:13:17.3 | HIP 117890 | 25.91 |
| 2026-09-25 12:00 | 23:55:40.97 | +37:11:44.8 | HIP 117890 | 26.12 |
| 2026-09-26 00:00 | 23:55:28.09 | +37:10:11.3 | HIP 117890 | 26.69 |
| 2026-09-26 12:00 | 23:55:15.23 | +37:08:36.7 | HIP 117890 | 27.58 |
| 2026-09-27 00:00 | 23:55:02.39 | +37:07:01.1 | HIP 117762 | 26.98 |
| 2026-09-27 12:00 | 23:54:49.58 | +37:05:24.4 | HIP 117762 | 24.03 |
| 2026-09-28 00:00 | 23:54:36.80 | +37:03:46.7 | HIP 117762 | 21.09 |
| 2026-09-28 12:00 | 23:54:24.05 | +37:02:08.0 | HIP 117762 | 18.18 |
| 2026-09-29 00:00 | 23:54:11.33 | +37:00:28.2 | HIP 117762 | 15.32 |
| 2026-09-29 12:00 | 23:53:58.65 | +36:58:47.4 | HIP 117762 | 12.54 |
| 2026-09-30 00:00 | 23:53:45.99 | +36:57:05.6 | HIP 117762 | 9.93 |
| 2026-09-30 12:00 | 23:53:33.38 | +36:55:22.9 | HIP 117762 | 7.64 |
| 2026-10-01 00:00 | 23:53:20.80 | +36:53:39.1 | HIP 117762 | 6.08 |
| 2026-10-01 12:00 | 23:53:08.25 | +36:51:54.3 | HIP 117762 | 5.87 |
| 2026-10-02 00:00 | 23:52:55.75 | +36:50:08.6 | HIP 117762 | 7.13 |
| 2026-10-02 12:00 | 23:52:43.29 | +36:48:21.9 | HIP 117762 | 9.28 |
| 2026-10-03 00:00 | 23:52:30.87 | +36:46:34.3 | HIP 117762 | 11.85 |
| 2026-10-03 12:00 | 23:52:18.50 | +36:44:45.7 | HIP 117762 | 14.62 |
| 2026-10-04 00:00 | 23:52:06.17 | +36:42:56.2 | HIP 117762 | 17.49 |
| 2026-10-04 12:00 | 23:51:53.88 | +36:41:05.8 | HIP 117693 | 19.94 |
| 2026-10-05 00:00 | 23:51:41.65 | +36:39:14.4 | HIP 117693 | 18.64 |
| 2026-10-05 12:00 | 23:51:29.47 | +36:37:22.2 | HIP 117693 | 17.76 |
| 2026-10-06 00:00 | 23:51:17.33 | +36:35:29.0 | HIP 117693 | 17.39 |
| 2026-10-06 12:00 | 23:51:05.25 | +36:33:35.0 | HIP 117693 | 17.53 |
| 2026-10-07 00:00 | 23:50:53.23 | +36:31:40.1 | HIP 117503 | 15.77 |
| 2026-10-07 12:00 | 23:50:41.25 | +36:29:44.4 | HIP 117503 | 12.84 |
| 2026-10-08 00:00 | 23:50:29.34 | +36:27:47.8 | HIP 117503 | 9.99 |
| 2026-10-08 12:00 | 23:50:17.48 | +36:25:50.3 | HIP 117503 | 7.35 |
| 2026-10-09 00:00 | 23:50:05.69 | +36:23:52.1 | HIP 117503 | 5.24 |
| 2026-10-09 12:00 | 23:49:53.95 | +36:21:53.0 | HIP 117503 | 4.48 |
| 2026-10-10 00:00 | 23:49:42.28 | +36:19:53.1 | HIP 117503 | 5.64 |
| 2026-10-10 12:00 | 23:49:30.67 | +36:17:52.5 | HIP 117503 | 7.92 |
| 2026-10-11 00:00 | 23:49:19.13 | +36:15:51.0 | HIP 117426 | 8.84 |