C/2019 K7 (Smith)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2019 K7 (Smith) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2020-06-16T23:22:59.520000Z |
| Orbit solution date (soln_date, UTC) | 2024-07-30T14:57:24Z |
| Obs used | 2719 |
| NEO | - |
| M1 | 10.100 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2019-05-30T13:34:05.376000Z |
| Discovery magnitude (MPC) | 17.70 c |
| Discovery observatory (MPC) | T05 · ATLAS-HKO, Haleakala |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2021-01-12.0000000 |
| e | 0.99998658 |
| q (au) | 4.475189 |
| a (au) | 333367.353622 |
| i (deg) | 103.541946 |
| Ω (om, deg) | 307.929065 |
| ω (w, deg) | 27.308050 |
| M (ma, deg) | 0.000001 |
等級
散乱 + 全体線形
$$ M_a = (10.047 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 10.047 |
| n | 2.000 |
| gf | 0.906 |
| gb | -0.650 |
| k | 0.965 |
| δ90 | 5.472 |
| 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 |
|---|---|---|---|
| 2017-10-08 | 2020-06-15 | +3.9313 | -2.529 |
| 2020-06-17 | 2021-04-08 | -4.3932 | +2.795 |
| 2021-04-08 | 2024-04-04 | +0.2227 | -0.255 |
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 | 10:47:29.83 | +52:52:07.4 | HIP 52826 | 7.32 |
| 2026-02-03 12:00 | 10:47:15.73 | +52:53:00.7 | HIP 52826 | 9.49 |
| 2026-02-04 00:00 | 10:47:01.57 | +52:53:53.4 | HIP 52826 | 11.72 |
| 2026-02-04 12:00 | 10:46:47.36 | +52:54:45.3 | HIP 52826 | 13.97 |
| 2026-02-05 00:00 | 10:46:33.09 | +52:55:36.5 | HIP 52826 | 16.24 |
| 2026-02-05 12:00 | 10:46:18.77 | +52:56:27.0 | HIP 52826 | 18.53 |
| 2026-02-06 00:00 | 10:46:04.40 | +52:57:16.8 | HIP 52826 | 20.81 |
| 2026-02-06 12:00 | 10:45:49.98 | +52:58:05.8 | HIP 52480 | 21.50 |
| 2026-02-07 00:00 | 10:45:35.51 | +52:58:54.0 | HIP 52480 | 19.21 |
| 2026-02-07 12:00 | 10:45:20.99 | +52:59:41.5 | HIP 52480 | 16.93 |
| 2026-02-08 00:00 | 10:45:06.43 | +53:00:28.3 | HIP 52480 | 14.66 |
| 2026-02-08 12:00 | 10:44:51.82 | +53:01:14.3 | HIP 52480 | 12.42 |
| 2026-02-09 00:00 | 10:44:37.16 | +53:01:59.5 | HIP 52480 | 10.22 |
| 2026-02-09 12:00 | 10:44:22.47 | +53:02:44.0 | HIP 52480 | 8.10 |
| 2026-02-10 00:00 | 10:44:07.73 | +53:03:27.6 | HIP 52480 | 6.14 |
| 2026-02-10 12:00 | 10:43:52.95 | +53:04:10.5 | HIP 52480 | 4.56 |
| 2026-02-11 00:00 | 10:43:38.14 | +53:04:52.6 | HIP 52480 | 3.85 |
| 2026-02-11 12:00 | 10:43:23.29 | +53:05:33.9 | HIP 52480 | 4.45 |
| 2026-02-12 00:00 | 10:43:08.40 | +53:06:14.3 | HIP 52480 | 5.98 |
| 2026-02-12 12:00 | 10:42:53.48 | +53:06:54.0 | HIP 52480 | 7.92 |
| 2026-02-13 00:00 | 10:42:38.52 | +53:07:32.8 | HIP 52480 | 10.04 |
| 2026-02-13 12:00 | 10:42:23.53 | +53:08:10.9 | HIP 52480 | 12.24 |
| 2026-02-14 00:00 | 10:42:08.52 | +53:08:48.0 | HIP 52309 | 13.02 |
| 2026-02-14 12:00 | 10:41:53.47 | +53:09:24.4 | HIP 52309 | 12.38 |
| 2026-02-15 00:00 | 10:41:38.40 | +53:10:00.0 | HIP 52309 | 12.16 |
| 2026-02-15 12:00 | 10:41:23.30 | +53:10:34.6 | HIP 52309 | 12.37 |
| 2026-02-16 00:00 | 10:41:08.18 | +53:11:08.4 | HIP 52309 | 12.98 |
| 2026-02-16 12:00 | 10:40:53.03 | +53:11:41.4 | HIP 52309 | 13.96 |
| 2026-02-17 00:00 | 10:40:37.86 | +53:12:13.5 | HIP 52309 | 15.22 |
| 2026-02-17 12:00 | 10:40:22.68 | +53:12:44.7 | HIP 52309 | 16.71 |
| 2026-02-18 00:00 | 10:40:07.47 | +53:13:15.1 | HIP 52309 | 18.36 |
| 2026-02-18 12:00 | 10:39:52.25 | +53:13:44.6 | HIP 52041 | 16.84 |
| 2026-02-19 00:00 | 10:39:37.01 | +53:14:13.3 | HIP 52041 | 14.61 |
| 2026-02-19 12:00 | 10:39:21.76 | +53:14:41.0 | HIP 52041 | 12.40 |
| 2026-02-20 00:00 | 10:39:06.50 | +53:15:07.9 | HIP 52041 | 10.26 |
| 2026-02-20 12:00 | 10:38:51.23 | +53:15:33.9 | HIP 52041 | 8.20 |
| 2026-02-21 00:00 | 10:38:35.95 | +53:15:59.0 | HIP 52041 | 6.32 |
| 2026-02-21 12:00 | 10:38:20.66 | +53:16:23.2 | HIP 52041 | 4.84 |
| 2026-02-22 00:00 | 10:38:05.36 | +53:16:46.5 | HIP 52041 | 4.19 |
| 2026-02-22 12:00 | 10:37:50.06 | +53:17:08.9 | HIP 52041 | 4.72 |
| 2026-02-23 00:00 | 10:37:34.76 | +53:17:30.5 | HIP 52041 | 6.14 |
| 2026-02-23 12:00 | 10:37:19.46 | +53:17:51.1 | HIP 52041 | 7.98 |
| 2026-02-24 00:00 | 10:37:04.15 | +53:18:10.8 | HIP 52041 | 10.01 |