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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 13:17:53.43 | +66:39:31.7 | HIP 64961 | 32.72 |
| 2026-05-12 12:00 | 13:17:42.75 | +66:39:01.4 | HIP 64961 | 33.42 |
| 2026-05-13 00:00 | 13:17:32.14 | +66:38:30.4 | HIP 64760 | 32.70 |
| 2026-05-13 12:00 | 13:17:21.59 | +66:37:58.8 | HIP 64760 | 31.97 |
| 2026-05-14 00:00 | 13:17:11.12 | +66:37:26.6 | HIP 64760 | 31.25 |
| 2026-05-14 12:00 | 13:17:00.71 | +66:36:53.8 | HIP 64760 | 30.55 |
| 2026-05-15 00:00 | 13:16:50.37 | +66:36:20.3 | HIP 64760 | 29.87 |
| 2026-05-15 12:00 | 13:16:40.11 | +66:35:46.2 | HIP 64760 | 29.21 |
| 2026-05-16 00:00 | 13:16:29.92 | +66:35:11.5 | HIP 64760 | 28.57 |
| 2026-05-16 12:00 | 13:16:19.81 | +66:34:36.1 | HIP 64760 | 27.96 |
| 2026-05-17 00:00 | 13:16:09.77 | +66:34:00.2 | HIP 64760 | 27.38 |
| 2026-05-17 12:00 | 13:15:59.80 | +66:33:23.7 | HIP 64760 | 26.82 |
| 2026-05-18 00:00 | 13:15:49.91 | +66:32:46.6 | HIP 64760 | 26.29 |
| 2026-05-18 12:00 | 13:15:40.10 | +66:32:08.9 | HIP 64760 | 25.80 |
| 2026-05-19 00:00 | 13:15:30.37 | +66:31:30.5 | HIP 64760 | 25.34 |
| 2026-05-19 12:00 | 13:15:20.71 | +66:30:51.7 | HIP 64760 | 24.91 |
| 2026-05-20 00:00 | 13:15:11.14 | +66:30:12.2 | HIP 64760 | 24.52 |
| 2026-05-20 12:00 | 13:15:01.64 | +66:29:32.2 | HIP 64760 | 24.17 |
| 2026-05-21 00:00 | 13:14:52.23 | +66:28:51.6 | HIP 64760 | 23.86 |
| 2026-05-21 12:00 | 13:14:42.90 | +66:28:10.4 | HIP 64760 | 23.59 |
| 2026-05-22 00:00 | 13:14:33.65 | +66:27:28.7 | HIP 64760 | 23.36 |
| 2026-05-22 12:00 | 13:14:24.48 | +66:26:46.4 | HIP 64760 | 23.18 |
| 2026-05-23 00:00 | 13:14:15.39 | +66:26:03.6 | HIP 64760 | 23.04 |
| 2026-05-23 12:00 | 13:14:06.39 | +66:25:20.2 | HIP 64760 | 22.95 |
| 2026-05-24 00:00 | 13:13:57.48 | +66:24:36.3 | HIP 64760 | 22.91 |
| 2026-05-24 12:00 | 13:13:48.65 | +66:23:51.9 | HIP 64760 | 22.91 |
| 2026-05-25 00:00 | 13:13:39.90 | +66:23:06.9 | HIP 64760 | 22.96 |
| 2026-05-25 12:00 | 13:13:31.25 | +66:22:21.4 | HIP 64760 | 23.05 |
| 2026-05-26 00:00 | 13:13:22.68 | +66:21:35.4 | HIP 64760 | 23.19 |
| 2026-05-26 12:00 | 13:13:14.19 | +66:20:48.9 | HIP 64760 | 23.38 |
| 2026-05-27 00:00 | 13:13:05.79 | +66:20:01.9 | HIP 64760 | 23.61 |
| 2026-05-27 12:00 | 13:12:57.49 | +66:19:14.3 | HIP 64760 | 23.88 |
| 2026-05-28 00:00 | 13:12:49.27 | +66:18:26.3 | HIP 64760 | 24.19 |
| 2026-05-28 12:00 | 13:12:41.13 | +66:17:37.8 | HIP 64760 | 24.55 |
| 2026-05-29 00:00 | 13:12:33.09 | +66:16:48.8 | HIP 64760 | 24.93 |
| 2026-05-29 12:00 | 13:12:25.14 | +66:15:59.3 | HIP 64760 | 25.36 |
| 2026-05-30 00:00 | 13:12:17.28 | +66:15:09.3 | HIP 64760 | 25.82 |
| 2026-05-30 12:00 | 13:12:09.51 | +66:14:18.9 | HIP 64760 | 26.31 |
| 2026-05-31 00:00 | 13:12:01.83 | +66:13:27.9 | HIP 64760 | 26.83 |
| 2026-05-31 12:00 | 13:11:54.24 | +66:12:36.6 | HIP 64760 | 27.38 |
| 2026-06-01 00:00 | 13:11:46.75 | +66:11:44.7 | HIP 64760 | 27.96 |
| 2026-06-01 12:00 | 13:11:39.34 | +66:10:52.4 | HIP 64760 | 28.56 |
| 2026-06-02 00:00 | 13:11:32.03 | +66:09:59.7 | HIP 64760 | 29.19 |