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
$$ M_a = (11.695 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 11.695 |
| 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 | +0.7784 | -0.530 |
| 2013-11-13 | 2013-11-28 | +7.8926 | -0.124 |
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 | 07:18:19.10 | +37:04:51.9 | HIP 35225 | 20.60 |
| 2026-05-12 12:00 | 07:18:21.54 | +37:04:36.2 | HIP 35225 | 21.15 |
| 2026-05-13 00:00 | 07:18:24.02 | +37:04:20.4 | HIP 35225 | 21.71 |
| 2026-05-13 12:00 | 07:18:26.53 | +37:04:04.7 | HIP 35225 | 22.28 |
| 2026-05-14 00:00 | 07:18:29.07 | +37:03:49.1 | HIP 35225 | 22.85 |
| 2026-05-14 12:00 | 07:18:31.64 | +37:03:33.4 | HIP 35225 | 23.42 |
| 2026-05-15 00:00 | 07:18:34.23 | +37:03:17.8 | HIP 35225 | 24.00 |
| 2026-05-15 12:00 | 07:18:36.86 | +37:03:02.2 | HIP 35477 | 24.28 |
| 2026-05-16 00:00 | 07:18:39.52 | +37:02:46.6 | HIP 35477 | 23.84 |
| 2026-05-16 12:00 | 07:18:42.20 | +37:02:31.0 | HIP 35477 | 23.41 |
| 2026-05-17 00:00 | 07:18:44.92 | +37:02:15.5 | HIP 35477 | 22.99 |
| 2026-05-17 12:00 | 07:18:47.66 | +37:02:00.0 | HIP 35477 | 22.57 |
| 2026-05-18 00:00 | 07:18:50.43 | +37:01:44.5 | HIP 35477 | 22.15 |
| 2026-05-18 12:00 | 07:18:53.23 | +37:01:29.1 | HIP 35477 | 21.75 |
| 2026-05-19 00:00 | 07:18:56.05 | +37:01:13.7 | HIP 35477 | 21.36 |
| 2026-05-19 12:00 | 07:18:58.91 | +37:00:58.3 | HIP 35477 | 20.97 |
| 2026-05-20 00:00 | 07:19:01.79 | +37:00:43.0 | HIP 35477 | 20.60 |
| 2026-05-20 12:00 | 07:19:04.70 | +37:00:27.7 | HIP 35477 | 20.24 |
| 2026-05-21 00:00 | 07:19:07.63 | +37:00:12.4 | HIP 35477 | 19.89 |
| 2026-05-21 12:00 | 07:19:10.60 | +36:59:57.2 | HIP 35477 | 19.56 |
| 2026-05-22 00:00 | 07:19:13.58 | +36:59:42.0 | HIP 35477 | 19.25 |
| 2026-05-22 12:00 | 07:19:16.60 | +36:59:26.8 | HIP 35477 | 18.95 |
| 2026-05-23 00:00 | 07:19:19.64 | +36:59:11.7 | HIP 35477 | 18.67 |
| 2026-05-23 12:00 | 07:19:22.70 | +36:58:56.7 | HIP 35477 | 18.41 |
| 2026-05-24 00:00 | 07:19:25.79 | +36:58:41.6 | HIP 35477 | 18.17 |
| 2026-05-24 12:00 | 07:19:28.91 | +36:58:26.6 | HIP 35477 | 17.95 |
| 2026-05-25 00:00 | 07:19:32.05 | +36:58:11.7 | HIP 35477 | 17.76 |
| 2026-05-25 12:00 | 07:19:35.22 | +36:57:56.8 | HIP 35477 | 17.60 |
| 2026-05-26 00:00 | 07:19:38.40 | +36:57:41.9 | HIP 35477 | 17.46 |
| 2026-05-26 12:00 | 07:19:41.62 | +36:57:27.1 | HIP 35477 | 17.34 |
| 2026-05-27 00:00 | 07:19:44.86 | +36:57:12.3 | HIP 35477 | 17.26 |
| 2026-05-27 12:00 | 07:19:48.12 | +36:56:57.6 | HIP 35477 | 17.21 |
| 2026-05-28 00:00 | 07:19:51.40 | +36:56:42.9 | HIP 35477 | 17.18 |
| 2026-05-28 12:00 | 07:19:54.71 | +36:56:28.3 | HIP 35477 | 17.19 |
| 2026-05-29 00:00 | 07:19:58.04 | +36:56:13.7 | HIP 35477 | 17.23 |
| 2026-05-29 12:00 | 07:20:01.39 | +36:55:59.2 | HIP 35477 | 17.30 |
| 2026-05-30 00:00 | 07:20:04.77 | +36:55:44.7 | HIP 35477 | 17.41 |
| 2026-05-30 12:00 | 07:20:08.16 | +36:55:30.3 | HIP 35477 | 17.54 |
| 2026-05-31 00:00 | 07:20:11.58 | +36:55:15.9 | HIP 35477 | 17.71 |
| 2026-05-31 12:00 | 07:20:15.02 | +36:55:01.6 | HIP 35477 | 17.91 |
| 2026-06-01 00:00 | 07:20:18.49 | +36:54:47.3 | HIP 35477 | 18.13 |
| 2026-06-01 12:00 | 07:20:21.97 | +36:54:33.1 | HIP 35477 | 18.39 |
| 2026-06-02 00:00 | 07:20:25.47 | +36:54:18.9 | HIP 35477 | 18.68 |