218P/LINEAR
メタデータ
| 項目 | 値 |
|---|---|
| Designation | 218P/LINEAR |
| Type | P |
| Perihelion (tp_cal, UTC) | 2015-04-23T12:22:13.497600Z |
| Orbit solution date (soln_date, UTC) | 2026-05-11T09:35:38Z |
| Obs used | 517 |
| NEO | Yes |
| M1 | 15.500 |
| K1 | 13.500 |
| PC | 0.030 |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2017-10-09.0000000 |
| e | 0.62196566 |
| q (au) | 1.170562 |
| a (au) | 3.096443 |
| i (deg) | 2.725398 |
| Ω (om, deg) | 176.027605 |
| ω (w, deg) | 59.673629 |
| M (ma, deg) | 162.705828 |
等級
散乱 + 全体線形
$$ M_a = (14.634 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 14.634 |
| n | 6.000 |
| gf | 1.000 |
| gb | -0.500 |
| k | 1.000 |
| 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 |
|---|---|---|---|
| 2023-12-21 | 2026-05-15 | -9.4317 | +1.112 |
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 | 22:56:52.81 | -06:11:56.0 | HIP 113279 | 22.31 |
| 2026-09-20 12:00 | 22:56:25.98 | -06:15:20.9 | HIP 113279 | 17.45 |
| 2026-09-21 00:00 | 22:55:59.49 | -06:18:43.3 | HIP 113279 | 14.96 |
| 2026-09-21 12:00 | 22:55:33.36 | -06:22:03.3 | HIP 113279 | 15.85 |
| 2026-09-22 00:00 | 22:55:07.58 | -06:25:20.6 | HIP 113279 | 19.56 |
| 2026-09-22 12:00 | 22:54:42.16 | -06:28:35.5 | HIP 113279 | 24.76 |
| 2026-09-23 00:00 | 22:54:17.10 | -06:31:47.7 | HIP 113150 | 27.05 |
| 2026-09-23 12:00 | 22:53:52.41 | -06:34:57.4 | HIP 113150 | 26.53 |
| 2026-09-24 00:00 | 22:53:28.10 | -06:38:04.5 | HIP 113150 | 27.74 |
| 2026-09-24 12:00 | 22:53:04.16 | -06:41:08.9 | HIP 113150 | 30.40 |
| 2026-09-25 00:00 | 22:52:40.59 | -06:44:10.6 | HIP 112796 | 33.85 |
| 2026-09-25 12:00 | 22:52:17.41 | -06:47:09.7 | HIP 112796 | 27.47 |
| 2026-09-26 00:00 | 22:51:54.61 | -06:50:06.1 | HIP 112796 | 21.25 |
| 2026-09-26 12:00 | 22:51:32.20 | -06:52:59.9 | HIP 112796 | 15.26 |
| 2026-09-27 00:00 | 22:51:10.18 | -06:55:50.9 | HIP 112796 | 9.75 |
| 2026-09-27 12:00 | 22:50:48.55 | -06:58:39.2 | HIP 112796 | 5.78 |
| 2026-09-28 00:00 | 22:50:27.31 | -07:01:24.7 | HIP 112774 | 4.45 |
| 2026-09-28 12:00 | 22:50:06.47 | -07:04:07.5 | HIP 112774 | 3.48 |
| 2026-09-29 00:00 | 22:49:46.03 | -07:06:47.6 | HIP 112774 | 8.41 |
| 2026-09-29 12:00 | 22:49:25.98 | -07:09:24.9 | HIP 112774 | 13.86 |
| 2026-09-30 00:00 | 22:49:06.34 | -07:11:59.4 | HIP 112774 | 19.30 |
| 2026-09-30 12:00 | 22:48:47.10 | -07:14:31.2 | HIP 112514 | 23.06 |
| 2026-10-01 00:00 | 22:48:28.27 | -07:17:00.2 | HIP 112514 | 17.77 |
| 2026-10-01 12:00 | 22:48:09.84 | -07:19:26.4 | HIP 112514 | 12.60 |
| 2026-10-02 00:00 | 22:47:51.82 | -07:21:49.8 | HIP 112514 | 7.55 |
| 2026-10-02 12:00 | 22:47:34.21 | -07:24:10.5 | HIP 112514 | 2.68 |
| 2026-10-03 00:00 | 22:47:17.01 | -07:26:28.3 | HIP 112514 | 2.43 |
| 2026-10-03 12:00 | 22:47:00.22 | -07:28:43.3 | HIP 112514 | 7.06 |
| 2026-10-04 00:00 | 22:46:43.85 | -07:30:55.5 | HIP 112514 | 11.66 |
| 2026-10-04 12:00 | 22:46:27.88 | -07:33:04.9 | HIP 112514 | 16.16 |
| 2026-10-05 00:00 | 22:46:12.34 | -07:35:11.5 | HIP 112514 | 20.55 |
| 2026-10-05 12:00 | 22:45:57.20 | -07:37:15.3 | HIP 112283 | 20.20 |
| 2026-10-06 00:00 | 22:45:42.48 | -07:39:16.2 | HIP 112283 | 16.70 |
| 2026-10-06 12:00 | 22:45:28.18 | -07:41:14.4 | HIP 112283 | 13.67 |
| 2026-10-07 00:00 | 22:45:14.30 | -07:43:09.7 | HIP 112283 | 11.36 |
| 2026-10-07 12:00 | 22:45:00.83 | -07:45:02.2 | HIP 112283 | 10.14 |
| 2026-10-08 00:00 | 22:44:47.78 | -07:46:51.9 | HIP 112283 | 10.28 |
| 2026-10-08 12:00 | 22:44:35.15 | -07:48:38.7 | HIP 112283 | 11.62 |
| 2026-10-09 00:00 | 22:44:22.94 | -07:50:22.8 | HIP 112283 | 13.72 |
| 2026-10-09 12:00 | 22:44:11.14 | -07:52:04.1 | HIP 112283 | 16.22 |
| 2026-10-10 00:00 | 22:43:59.76 | -07:53:42.5 | HIP 112283 | 18.90 |
| 2026-10-10 12:00 | 22:43:48.80 | -07:55:18.2 | HIP 112283 | 21.65 |
| 2026-10-11 00:00 | 22:43:38.26 | -07:56:51.0 | HIP 112168 | 23.48 |