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) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 10:31:52.34 | +46:21:04.1 | HIP 51599 | 11.90 |
| 2026-09-20 12:00 | 10:31:59.84 | +46:20:45.6 | HIP 51599 | 11.64 |
| 2026-09-21 00:00 | 10:32:07.31 | +46:20:27.7 | HIP 51599 | 11.51 |
| 2026-09-21 12:00 | 10:32:14.75 | +46:20:10.3 | HIP 51599 | 11.53 |
| 2026-09-22 00:00 | 10:32:22.16 | +46:19:53.5 | HIP 51599 | 11.69 |
| 2026-09-22 12:00 | 10:32:29.54 | +46:19:37.4 | HIP 51599 | 11.98 |
| 2026-09-23 00:00 | 10:32:36.88 | +46:19:21.7 | HIP 51599 | 12.38 |
| 2026-09-23 12:00 | 10:32:44.20 | +46:19:06.7 | HIP 51599 | 12.90 |
| 2026-09-24 00:00 | 10:32:51.48 | +46:18:52.3 | HIP 51715 | 13.25 |
| 2026-09-24 12:00 | 10:32:58.73 | +46:18:38.4 | HIP 51715 | 12.05 |
| 2026-09-25 00:00 | 10:33:05.94 | +46:18:25.2 | HIP 51715 | 10.89 |
| 2026-09-25 12:00 | 10:33:13.12 | +46:18:12.5 | HIP 51715 | 9.75 |
| 2026-09-26 00:00 | 10:33:20.27 | +46:18:00.4 | HIP 51715 | 8.67 |
| 2026-09-26 12:00 | 10:33:27.38 | +46:17:48.8 | HIP 51715 | 7.64 |
| 2026-09-27 00:00 | 10:33:34.45 | +46:17:37.9 | HIP 51715 | 6.70 |
| 2026-09-27 12:00 | 10:33:41.49 | +46:17:27.6 | HIP 51715 | 5.89 |
| 2026-09-28 00:00 | 10:33:48.50 | +46:17:17.8 | HIP 51715 | 5.25 |
| 2026-09-28 12:00 | 10:33:55.46 | +46:17:08.6 | HIP 51715 | 4.85 |
| 2026-09-29 00:00 | 10:34:02.39 | +46:17:00.1 | HIP 51715 | 4.74 |
| 2026-09-29 12:00 | 10:34:09.28 | +46:16:52.1 | HIP 51715 | 4.94 |
| 2026-09-30 00:00 | 10:34:16.13 | +46:16:44.7 | HIP 51715 | 5.41 |
| 2026-09-30 12:00 | 10:34:22.95 | +46:16:37.9 | HIP 51715 | 6.09 |
| 2026-10-01 00:00 | 10:34:29.72 | +46:16:31.7 | HIP 51715 | 6.90 |
| 2026-10-01 12:00 | 10:34:36.45 | +46:16:26.0 | HIP 51715 | 7.80 |
| 2026-10-02 00:00 | 10:34:43.15 | +46:16:21.0 | HIP 51715 | 8.77 |
| 2026-10-02 12:00 | 10:34:49.80 | +46:16:16.6 | HIP 51824 | 9.12 |
| 2026-10-03 00:00 | 10:34:56.41 | +46:16:12.7 | HIP 51841 | 8.56 |
| 2026-10-03 12:00 | 10:35:02.98 | +46:16:09.5 | HIP 51841 | 7.80 |
| 2026-10-04 00:00 | 10:35:09.50 | +46:16:06.9 | HIP 51841 | 7.15 |
| 2026-10-04 12:00 | 10:35:15.99 | +46:16:04.8 | HIP 51841 | 6.65 |
| 2026-10-05 00:00 | 10:35:22.42 | +46:16:03.4 | HIP 51841 | 6.32 |
| 2026-10-05 12:00 | 10:35:28.82 | +46:16:02.5 | HIP 51841 | 6.18 |
| 2026-10-06 00:00 | 10:35:35.17 | +46:16:02.3 | HIP 51841 | 6.25 |
| 2026-10-06 12:00 | 10:35:41.47 | +46:16:02.6 | HIP 51841 | 6.51 |
| 2026-10-07 00:00 | 10:35:47.73 | +46:16:03.6 | HIP 51841 | 6.95 |
| 2026-10-07 12:00 | 10:35:53.94 | +46:16:05.1 | HIP 51841 | 7.51 |
| 2026-10-08 00:00 | 10:36:00.10 | +46:16:07.3 | HIP 51841 | 8.19 |
| 2026-10-08 12:00 | 10:36:06.22 | +46:16:10.0 | HIP 51841 | 8.94 |
| 2026-10-09 00:00 | 10:36:12.29 | +46:16:13.4 | HIP 51841 | 9.75 |
| 2026-10-09 12:00 | 10:36:18.31 | +46:16:17.4 | HIP 51841 | 10.60 |
| 2026-10-10 00:00 | 10:36:24.27 | +46:16:21.9 | HIP 51841 | 11.48 |
| 2026-10-10 12:00 | 10:36:30.19 | +46:16:27.1 | HIP 51841 | 12.38 |
| 2026-10-11 00:00 | 10:36:36.06 | +46:16:32.9 | HIP 51841 | 13.30 |