C/2020 R7 (ATLAS)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2020 R7 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2022-09-16T06:03:23.394240Z |
| Orbit solution date (soln_date, UTC) | 2024-08-11T00:12:15Z |
| Obs used | 1812 |
| NEO | - |
| M1 | 11.500 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2020-09-15T14:23:18.614400Z |
| Discovery magnitude (MPC) | 19.00 o |
| Discovery observatory (MPC) | T08 · ATLAS-MLO, Mauna Loa |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2023-02-02.0000000 |
| e | 1.00021432 |
| q (au) | 2.956013 |
| a (au) | -13792.591193 |
| i (deg) | 114.893954 |
| Ω (om, deg) | 268.282599 |
| ω (w, deg) | 347.841392 |
| M (ma, deg) | 0.000084 |
等級
散乱 + 全体線形
$$ M_a = (9.379 + 2.863\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 9.379 |
| n | 2.863 |
| gf | 0.980 |
| gb | -1.000 |
| k | 0.999 |
| δ90 | 9.998 |
| 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 |
|---|---|---|---|
| 2019-12-03 | 2020-09-23 | +20.8410 | -18.349 |
| 2020-09-23 | 2021-08-10 | +4.7347 | -4.468 |
| 2021-08-10 | 2022-03-31 | -0.0032 | -1.068 |
| 2022-03-31 | 2022-09-15 | -12.9278 | +5.677 |
| 2022-09-19 | 2024-07-31 | +4.7248 | -2.800 |
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) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 13:54:21.00 | +66:27:35.3 | HIP 67977 | 21.29 |
| 2026-02-03 12:00 | 13:54:08.46 | +66:30:51.9 | HIP 67977 | 24.78 |
| 2026-02-04 00:00 | 13:53:55.63 | +66:34:08.2 | HIP 68076 | 26.56 |
| 2026-02-04 12:00 | 13:53:42.52 | +66:37:24.0 | HIP 68076 | 24.62 |
| 2026-02-05 00:00 | 13:53:29.12 | +66:40:39.4 | HIP 68076 | 23.08 |
| 2026-02-05 12:00 | 13:53:15.43 | +66:43:54.3 | HIP 68076 | 22.03 |
| 2026-02-06 00:00 | 13:53:01.44 | +66:47:08.8 | HIP 68076 | 21.53 |
| 2026-02-06 12:00 | 13:52:47.17 | +66:50:22.8 | HIP 68076 | 21.62 |
| 2026-02-07 00:00 | 13:52:32.61 | +66:53:36.3 | HIP 68076 | 22.30 |
| 2026-02-07 12:00 | 13:52:17.75 | +66:56:49.3 | HIP 68076 | 23.52 |
| 2026-02-08 00:00 | 13:52:02.60 | +67:00:01.7 | HIP 68076 | 25.20 |
| 2026-02-08 12:00 | 13:51:47.15 | +67:03:13.6 | HIP 68076 | 27.25 |
| 2026-02-09 00:00 | 13:51:31.41 | +67:06:24.9 | HIP 67273 | 29.50 |
| 2026-02-09 12:00 | 13:51:15.37 | +67:09:35.6 | HIP 67273 | 26.52 |
| 2026-02-10 00:00 | 13:50:59.04 | +67:12:45.6 | HIP 67273 | 23.68 |
| 2026-02-10 12:00 | 13:50:42.41 | +67:15:55.1 | HIP 67273 | 21.03 |
| 2026-02-11 00:00 | 13:50:25.48 | +67:19:03.9 | HIP 67273 | 18.66 |
| 2026-02-11 12:00 | 13:50:08.25 | +67:22:12.0 | HIP 67273 | 16.69 |
| 2026-02-12 00:00 | 13:49:50.72 | +67:25:19.4 | HIP 67273 | 15.28 |
| 2026-02-12 12:00 | 13:49:32.90 | +67:28:26.1 | HIP 67273 | 14.59 |
| 2026-02-13 00:00 | 13:49:14.78 | +67:31:32.1 | HIP 67273 | 14.73 |
| 2026-02-13 12:00 | 13:48:56.35 | +67:34:37.3 | HIP 67273 | 15.66 |
| 2026-02-14 00:00 | 13:48:37.63 | +67:37:41.7 | HIP 67273 | 17.27 |
| 2026-02-14 12:00 | 13:48:18.61 | +67:40:45.3 | HIP 67273 | 19.39 |
| 2026-02-15 00:00 | 13:47:59.28 | +67:43:48.1 | HIP 67273 | 21.87 |
| 2026-02-15 12:00 | 13:47:39.66 | +67:46:50.1 | HIP 67273 | 24.60 |
| 2026-02-16 00:00 | 13:47:19.73 | +67:49:51.2 | HIP 67273 | 27.51 |
| 2026-02-16 12:00 | 13:46:59.51 | +67:52:51.4 | HIP 67273 | 30.54 |
| 2026-02-17 00:00 | 13:46:38.99 | +67:55:50.8 | HIP 67589 | 33.48 |
| 2026-02-17 12:00 | 13:46:18.16 | +67:58:49.2 | HIP 67058 | 30.70 |
| 2026-02-18 00:00 | 13:45:57.04 | +68:01:46.7 | HIP 67058 | 27.28 |
| 2026-02-18 12:00 | 13:45:35.62 | +68:04:43.2 | HIP 67058 | 23.90 |
| 2026-02-19 00:00 | 13:45:13.90 | +68:07:38.7 | HIP 67058 | 20.59 |
| 2026-02-19 12:00 | 13:44:51.88 | +68:10:33.2 | HIP 67058 | 17.40 |
| 2026-02-20 00:00 | 13:44:29.57 | +68:13:26.8 | HIP 67058 | 14.39 |
| 2026-02-20 12:00 | 13:44:06.96 | +68:16:19.2 | HIP 67058 | 11.70 |
| 2026-02-21 00:00 | 13:43:44.05 | +68:19:10.7 | HIP 67058 | 9.62 |
| 2026-02-21 12:00 | 13:43:20.85 | +68:22:01.0 | HIP 67058 | 8.60 |
| 2026-02-22 00:00 | 13:42:57.36 | +68:24:50.2 | HIP 67058 | 9.00 |
| 2026-02-22 12:00 | 13:42:33.57 | +68:27:38.4 | HIP 67058 | 10.66 |
| 2026-02-23 00:00 | 13:42:09.49 | +68:30:25.4 | HIP 67058 | 13.12 |
| 2026-02-23 12:00 | 13:41:45.12 | +68:33:11.2 | HIP 67058 | 16.00 |
| 2026-02-24 00:00 | 13:41:20.46 | +68:35:55.9 | HIP 67058 | 19.12 |