C/2012 S1 (ISON)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2012 S1 (ISON) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2013-11-28T18:20:55.495680Z |
| Orbit solution date (soln_date, UTC) | 2025-11-21T13:42:48Z |
| Obs used | 6684 |
| NEO | - |
| M1 | 10.400 |
| K1 | 4.500 |
| PC | - |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2013-05-01.0000000 |
| e | 1.00000509 |
| q (au) | 0.012467 |
| a (au) | -2446.893404 |
| i (deg) | 62.162896 |
| Ω (om, deg) | 295.686541 |
| ω (w, deg) | 345.541197 |
| M (ma, deg) | -0.001724 |
等級
散乱 + 全体線形
$$ M_a = (11.693 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 11.693 |
| n | 2.000 |
| gf | 1.000 |
| gb | -0.791 |
| k | 0.951 |
| δ90 | 10.000 |
| 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 |
|---|---|---|---|
| 2011-09-30 | 2013-11-13 | +0.7860 | -0.537 |
| 2013-11-13 | 2013-11-28 | +7.8658 | -0.141 |
| 2013-12-04 | 2013-12-16 | +2.1648 | +1.197 |
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) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 07:22:07.30 | +37:40:55.2 | HIP 35662 | 7.29 |
| 2026-02-03 12:00 | 07:22:02.86 | +37:40:55.3 | HIP 35662 | 6.43 |
| 2026-02-04 00:00 | 07:21:58.43 | +37:40:55.3 | HIP 35662 | 5.57 |
| 2026-02-04 12:00 | 07:21:54.03 | +37:40:55.2 | HIP 35662 | 4.72 |
| 2026-02-05 00:00 | 07:21:49.64 | +37:40:54.8 | HIP 35662 | 3.88 |
| 2026-02-05 12:00 | 07:21:45.28 | +37:40:54.3 | HIP 35662 | 3.06 |
| 2026-02-06 00:00 | 07:21:40.94 | +37:40:53.7 | HIP 35662 | 2.28 |
| 2026-02-06 12:00 | 07:21:36.62 | +37:40:52.9 | HIP 35662 | 1.58 |
| 2026-02-07 00:00 | 07:21:32.32 | +37:40:51.9 | HIP 35662 | 1.12 |
| 2026-02-07 12:00 | 07:21:28.05 | +37:40:50.7 | HIP 35662 | 1.20 |
| 2026-02-08 00:00 | 07:21:23.80 | +37:40:49.4 | HIP 35662 | 1.75 |
| 2026-02-08 12:00 | 07:21:19.57 | +37:40:48.0 | HIP 35662 | 2.46 |
| 2026-02-09 00:00 | 07:21:15.36 | +37:40:46.3 | HIP 35662 | 3.23 |
| 2026-02-09 12:00 | 07:21:11.18 | +37:40:44.5 | HIP 35662 | 4.02 |
| 2026-02-10 00:00 | 07:21:07.03 | +37:40:42.6 | HIP 35662 | 4.81 |
| 2026-02-10 12:00 | 07:21:02.89 | +37:40:40.5 | HIP 35662 | 5.61 |
| 2026-02-11 00:00 | 07:20:58.79 | +37:40:38.2 | HIP 35662 | 6.41 |
| 2026-02-11 12:00 | 07:20:54.71 | +37:40:35.7 | HIP 35662 | 7.21 |
| 2026-02-12 00:00 | 07:20:50.65 | +37:40:33.2 | HIP 35662 | 8.00 |
| 2026-02-12 12:00 | 07:20:46.62 | +37:40:30.4 | HIP 35662 | 8.79 |
| 2026-02-13 00:00 | 07:20:42.61 | +37:40:27.5 | HIP 35662 | 9.58 |
| 2026-02-13 12:00 | 07:20:38.64 | +37:40:24.4 | HIP 35662 | 10.36 |
| 2026-02-14 00:00 | 07:20:34.69 | +37:40:21.2 | HIP 35662 | 11.14 |
| 2026-02-14 12:00 | 07:20:30.76 | +37:40:17.8 | HIP 35662 | 11.91 |
| 2026-02-15 00:00 | 07:20:26.87 | +37:40:14.3 | HIP 35662 | 12.68 |
| 2026-02-15 12:00 | 07:20:23.00 | +37:40:10.6 | HIP 35662 | 13.44 |
| 2026-02-16 00:00 | 07:20:19.16 | +37:40:06.7 | HIP 35662 | 14.20 |
| 2026-02-16 12:00 | 07:20:15.35 | +37:40:02.7 | HIP 35662 | 14.95 |
| 2026-02-17 00:00 | 07:20:11.57 | +37:39:58.5 | HIP 35662 | 15.70 |
| 2026-02-17 12:00 | 07:20:07.81 | +37:39:54.2 | HIP 35662 | 16.44 |
| 2026-02-18 00:00 | 07:20:04.09 | +37:39:49.8 | HIP 35662 | 17.18 |
| 2026-02-18 12:00 | 07:20:00.40 | +37:39:45.1 | HIP 35662 | 17.91 |
| 2026-02-19 00:00 | 07:19:56.73 | +37:39:40.4 | HIP 35662 | 18.64 |
| 2026-02-19 12:00 | 07:19:53.10 | +37:39:35.4 | HIP 35662 | 19.36 |
| 2026-02-20 00:00 | 07:19:49.50 | +37:39:30.4 | HIP 35662 | 20.07 |
| 2026-02-20 12:00 | 07:19:45.93 | +37:39:25.1 | HIP 35662 | 20.78 |
| 2026-02-21 00:00 | 07:19:42.39 | +37:39:19.8 | HIP 35662 | 21.48 |
| 2026-02-21 12:00 | 07:19:38.88 | +37:39:14.2 | HIP 35662 | 22.18 |
| 2026-02-22 00:00 | 07:19:35.40 | +37:39:08.6 | HIP 35662 | 22.87 |
| 2026-02-22 12:00 | 07:19:31.96 | +37:39:02.8 | HIP 35662 | 23.55 |
| 2026-02-23 00:00 | 07:19:28.54 | +37:38:56.8 | HIP 35662 | 24.23 |
| 2026-02-23 12:00 | 07:19:25.16 | +37:38:50.7 | HIP 35662 | 24.90 |
| 2026-02-24 00:00 | 07:19:21.82 | +37:38:44.5 | HIP 35276 | 25.08 |