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 | 5.474 |
| 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) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 10:17:40.34 | +47:43:25.4 | HIP 50366 | 25.77 |
| 2026-07-29 12:00 | 10:17:47.90 | +47:42:14.9 | HIP 50366 | 25.02 |
| 2026-07-30 00:00 | 10:17:55.49 | +47:41:04.7 | HIP 50366 | 24.37 |
| 2026-07-30 12:00 | 10:18:03.10 | +47:39:54.9 | HIP 50366 | 23.83 |
| 2026-07-31 00:00 | 10:18:10.75 | +47:38:45.5 | HIP 50366 | 23.43 |
| 2026-07-31 12:00 | 10:18:18.42 | +47:37:36.5 | HIP 50366 | 23.15 |
| 2026-08-01 00:00 | 10:18:26.11 | +47:36:27.9 | HIP 50366 | 23.01 |
| 2026-08-01 12:00 | 10:18:33.83 | +47:35:19.6 | HIP 50366 | 23.01 |
| 2026-08-02 00:00 | 10:18:41.57 | +47:34:11.8 | HIP 50366 | 23.14 |
| 2026-08-02 12:00 | 10:18:49.34 | +47:33:04.3 | HIP 50366 | 23.41 |
| 2026-08-03 00:00 | 10:18:57.13 | +47:31:57.2 | HIP 50366 | 23.81 |
| 2026-08-03 12:00 | 10:19:04.95 | +47:30:50.5 | HIP 50366 | 24.34 |
| 2026-08-04 00:00 | 10:19:12.78 | +47:29:44.2 | HIP 50366 | 24.98 |
| 2026-08-04 12:00 | 10:19:20.64 | +47:28:38.4 | HIP 50366 | 25.73 |
| 2026-08-05 00:00 | 10:19:28.53 | +47:27:32.9 | HIP 50366 | 26.57 |
| 2026-08-05 12:00 | 10:19:36.43 | +47:26:27.8 | HIP 50366 | 27.50 |
| 2026-08-06 00:00 | 10:19:44.35 | +47:25:23.2 | HIP 50366 | 28.52 |
| 2026-08-06 12:00 | 10:19:52.29 | +47:24:18.9 | HIP 50366 | 29.60 |
| 2026-08-07 00:00 | 10:20:00.26 | +47:23:15.1 | HIP 50366 | 30.75 |
| 2026-08-07 12:00 | 10:20:08.24 | +47:22:11.6 | HIP 50366 | 31.95 |
| 2026-08-08 00:00 | 10:20:16.24 | +47:21:08.6 | HIP 50366 | 33.21 |
| 2026-08-08 12:00 | 10:20:24.26 | +47:20:06.1 | HIP 50727 | 32.07 |
| 2026-08-09 00:00 | 10:20:32.29 | +47:19:03.9 | HIP 50727 | 30.65 |
| 2026-08-09 12:00 | 10:20:40.35 | +47:18:02.2 | HIP 50727 | 29.27 |
| 2026-08-10 00:00 | 10:20:48.41 | +47:17:00.9 | HIP 50727 | 27.93 |
| 2026-08-10 12:00 | 10:20:56.50 | +47:16:00.0 | HIP 50727 | 26.64 |
| 2026-08-11 00:00 | 10:21:04.60 | +47:14:59.6 | HIP 50727 | 25.41 |
| 2026-08-11 12:00 | 10:21:12.71 | +47:13:59.6 | HIP 50876 | 23.73 |
| 2026-08-12 00:00 | 10:21:20.84 | +47:13:00.1 | HIP 50876 | 22.06 |
| 2026-08-12 12:00 | 10:21:28.98 | +47:12:01.0 | HIP 50876 | 20.39 |
| 2026-08-13 00:00 | 10:21:37.14 | +47:11:02.3 | HIP 50876 | 18.73 |
| 2026-08-13 12:00 | 10:21:45.30 | +47:10:04.1 | HIP 50876 | 17.08 |
| 2026-08-14 00:00 | 10:21:53.48 | +47:09:06.4 | HIP 50876 | 15.43 |
| 2026-08-14 12:00 | 10:22:01.67 | +47:08:09.1 | HIP 50876 | 13.80 |
| 2026-08-15 00:00 | 10:22:09.87 | +47:07:12.3 | HIP 50876 | 12.18 |
| 2026-08-15 12:00 | 10:22:18.08 | +47:06:15.9 | HIP 50876 | 10.58 |
| 2026-08-16 00:00 | 10:22:26.29 | +47:05:20.0 | HIP 50876 | 9.01 |
| 2026-08-16 12:00 | 10:22:34.52 | +47:04:24.6 | HIP 50876 | 7.48 |
| 2026-08-17 00:00 | 10:22:42.75 | +47:03:29.6 | HIP 50876 | 6.04 |
| 2026-08-17 12:00 | 10:22:51.00 | +47:02:35.1 | HIP 50876 | 4.75 |
| 2026-08-18 00:00 | 10:22:59.24 | +47:01:41.0 | HIP 50876 | 3.76 |
| 2026-08-18 12:00 | 10:23:07.50 | +47:00:47.5 | HIP 50876 | 3.36 |
| 2026-08-19 00:00 | 10:23:15.76 | +46:59:54.4 | HIP 50876 | 3.73 |