C/2017 S3 (PANSTARRS)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2017 S3 (PANSTARRS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2018-08-15T22:45:39.003840Z |
| Orbit solution date (soln_date, UTC) | 2021-04-16T12:04:16Z |
| Obs used | 986 |
| NEO | - |
| M1 | 13.200 |
| K1 | 8.250 |
| PC | - |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2018-04-27.0000000 |
| e | 1.00007796 |
| q (au) | 0.208446 |
| a (au) | -2673.667700 |
| i (deg) | 99.038653 |
| Ω (om, deg) | 171.042492 |
| ω (w, deg) | 255.892231 |
| M (ma, deg) | -0.000791 |
等級
散乱 + 全体線形
$$ M_a = (9.352 + 4.553\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 9.352 |
| n | 4.553 |
| gf | 0.800 |
| gb | -0.500 |
| k | 1.000 |
| δ90 | 1.000 |
| 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 |
|---|---|---|---|
| 2017-08-17 | 2018-06-23 | -3.2015 | +2.122 |
| 2018-06-23 | 2018-07-06 | +31.4848 | -3.170 |
| 2018-07-06 | 2018-07-15 | -12.2246 | +0.039 |
| 2018-07-15 | 2018-07-21 | +4.0302 | -0.473 |
| 2018-07-21 | 2018-08-03 | -20.0442 | -1.795 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 13:08:16.57 | +64:02:14.1 | HIP 64402 | 24.51 |
| 2026-07-29 12:00 | 13:08:20.18 | +64:01:03.8 | HIP 64402 | 24.02 |
| 2026-07-30 00:00 | 13:08:23.87 | +63:59:53.5 | HIP 64402 | 23.57 |
| 2026-07-30 12:00 | 13:08:27.65 | +63:58:43.4 | HIP 64402 | 23.17 |
| 2026-07-31 00:00 | 13:08:31.50 | +63:57:33.5 | HIP 64402 | 22.82 |
| 2026-07-31 12:00 | 13:08:35.43 | +63:56:23.7 | HIP 64402 | 22.53 |
| 2026-08-01 00:00 | 13:08:39.44 | +63:55:14.0 | HIP 64402 | 22.29 |
| 2026-08-01 12:00 | 13:08:43.53 | +63:54:04.5 | HIP 64402 | 22.10 |
| 2026-08-02 00:00 | 13:08:47.70 | +63:52:55.1 | HIP 64402 | 21.98 |
| 2026-08-02 12:00 | 13:08:51.95 | +63:51:45.9 | HIP 64402 | 21.92 |
| 2026-08-03 00:00 | 13:08:56.27 | +63:50:36.8 | HIP 64402 | 21.92 |
| 2026-08-03 12:00 | 13:09:00.68 | +63:49:28.0 | HIP 64402 | 21.98 |
| 2026-08-04 00:00 | 13:09:05.16 | +63:48:19.2 | HIP 64402 | 22.10 |
| 2026-08-04 12:00 | 13:09:09.71 | +63:47:10.7 | HIP 64402 | 22.28 |
| 2026-08-05 00:00 | 13:09:14.34 | +63:46:02.3 | HIP 64402 | 22.51 |
| 2026-08-05 12:00 | 13:09:19.05 | +63:44:54.2 | HIP 64402 | 22.81 |
| 2026-08-06 00:00 | 13:09:23.83 | +63:43:46.2 | HIP 64402 | 23.16 |
| 2026-08-06 12:00 | 13:09:28.69 | +63:42:38.4 | HIP 64402 | 23.56 |
| 2026-08-07 00:00 | 13:09:33.63 | +63:41:30.8 | HIP 64402 | 24.02 |
| 2026-08-07 12:00 | 13:09:38.63 | +63:40:23.4 | HIP 64402 | 24.52 |
| 2026-08-08 00:00 | 13:09:43.71 | +63:39:16.2 | HIP 64402 | 25.06 |
| 2026-08-08 12:00 | 13:09:48.87 | +63:38:09.2 | HIP 64402 | 25.65 |
| 2026-08-09 00:00 | 13:09:54.10 | +63:37:02.4 | HIP 64402 | 26.28 |
| 2026-08-09 12:00 | 13:09:59.40 | +63:35:55.8 | HIP 64402 | 26.94 |
| 2026-08-10 00:00 | 13:10:04.77 | +63:34:49.5 | HIP 64347 | 27.50 |
| 2026-08-10 12:00 | 13:10:10.21 | +63:33:43.4 | HIP 64347 | 26.26 |
| 2026-08-11 00:00 | 13:10:15.73 | +63:32:37.5 | HIP 64347 | 25.02 |
| 2026-08-11 12:00 | 13:10:21.32 | +63:31:31.9 | HIP 64347 | 23.79 |
| 2026-08-12 00:00 | 13:10:26.97 | +63:30:26.4 | HIP 64347 | 22.57 |
| 2026-08-12 12:00 | 13:10:32.70 | +63:29:21.3 | HIP 64347 | 21.35 |
| 2026-08-13 00:00 | 13:10:38.50 | +63:28:16.4 | HIP 64347 | 20.14 |
| 2026-08-13 12:00 | 13:10:44.36 | +63:27:11.7 | HIP 64347 | 18.93 |
| 2026-08-14 00:00 | 13:10:50.30 | +63:26:07.3 | HIP 64347 | 17.74 |
| 2026-08-14 12:00 | 13:10:56.30 | +63:25:03.1 | HIP 64347 | 16.56 |
| 2026-08-15 00:00 | 13:11:02.37 | +63:23:59.3 | HIP 64347 | 15.40 |
| 2026-08-15 12:00 | 13:11:08.50 | +63:22:55.6 | HIP 64347 | 14.25 |
| 2026-08-16 00:00 | 13:11:14.71 | +63:21:52.3 | HIP 64347 | 13.14 |
| 2026-08-16 12:00 | 13:11:20.97 | +63:20:49.2 | HIP 64347 | 12.05 |
| 2026-08-17 00:00 | 13:11:27.31 | +63:19:46.5 | HIP 64347 | 11.01 |
| 2026-08-17 12:00 | 13:11:33.71 | +63:18:44.0 | HIP 64347 | 10.03 |
| 2026-08-18 00:00 | 13:11:40.17 | +63:17:41.8 | HIP 64347 | 9.13 |
| 2026-08-18 12:00 | 13:11:46.69 | +63:16:39.9 | HIP 64347 | 8.33 |
| 2026-08-19 00:00 | 13:11:53.28 | +63:15:38.2 | HIP 64347 | 7.66 |