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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 10:09:35.15 | +51:28:50.9 | HIP 49708 | 18.27 |
| 2026-05-12 12:00 | 10:09:31.80 | +51:27:24.5 | HIP 49708 | 19.45 |
| 2026-05-13 00:00 | 10:09:28.55 | +51:25:57.9 | HIP 49708 | 20.69 |
| 2026-05-13 12:00 | 10:09:25.41 | +51:24:31.0 | HIP 49708 | 21.97 |
| 2026-05-14 00:00 | 10:09:22.37 | +51:23:03.9 | HIP 49798 | 22.78 |
| 2026-05-14 12:00 | 10:09:19.44 | +51:21:36.5 | HIP 49798 | 21.47 |
| 2026-05-15 00:00 | 10:09:16.61 | +51:20:08.9 | HIP 49798 | 20.18 |
| 2026-05-15 12:00 | 10:09:13.88 | +51:18:41.0 | HIP 49798 | 18.92 |
| 2026-05-16 00:00 | 10:09:11.26 | +51:17:12.9 | HIP 49798 | 17.69 |
| 2026-05-16 12:00 | 10:09:08.74 | +51:15:44.6 | HIP 49798 | 16.50 |
| 2026-05-17 00:00 | 10:09:06.33 | +51:14:16.1 | HIP 49798 | 15.36 |
| 2026-05-17 12:00 | 10:09:04.02 | +51:12:47.4 | HIP 49798 | 14.28 |
| 2026-05-18 00:00 | 10:09:01.81 | +51:11:18.4 | HIP 49798 | 13.28 |
| 2026-05-18 12:00 | 10:08:59.70 | +51:09:49.3 | HIP 49798 | 12.36 |
| 2026-05-19 00:00 | 10:08:57.69 | +51:08:20.0 | HIP 49798 | 11.56 |
| 2026-05-19 12:00 | 10:08:55.79 | +51:06:50.5 | HIP 49798 | 10.90 |
| 2026-05-20 00:00 | 10:08:53.99 | +51:05:20.8 | HIP 49798 | 10.41 |
| 2026-05-20 12:00 | 10:08:52.29 | +51:03:50.9 | HIP 49798 | 10.11 |
| 2026-05-21 00:00 | 10:08:50.69 | +51:02:20.9 | HIP 49798 | 10.02 |
| 2026-05-21 12:00 | 10:08:49.19 | +51:00:50.8 | HIP 49798 | 10.14 |
| 2026-05-22 00:00 | 10:08:47.78 | +50:59:20.4 | HIP 49798 | 10.47 |
| 2026-05-22 12:00 | 10:08:46.48 | +50:57:50.0 | HIP 49727 | 9.22 |
| 2026-05-23 00:00 | 10:08:45.28 | +50:56:19.4 | HIP 49727 | 7.92 |
| 2026-05-23 12:00 | 10:08:44.17 | +50:54:48.6 | HIP 49727 | 6.71 |
| 2026-05-24 00:00 | 10:08:43.17 | +50:53:17.7 | HIP 49727 | 5.64 |
| 2026-05-24 12:00 | 10:08:42.26 | +50:51:46.7 | HIP 49727 | 4.81 |
| 2026-05-25 00:00 | 10:08:41.44 | +50:50:15.6 | HIP 49727 | 4.35 |
| 2026-05-25 12:00 | 10:08:40.73 | +50:48:44.4 | HIP 49727 | 4.38 |
| 2026-05-26 00:00 | 10:08:40.11 | +50:47:13.0 | HIP 49727 | 4.90 |
| 2026-05-26 12:00 | 10:08:39.58 | +50:45:41.6 | HIP 49727 | 5.78 |
| 2026-05-27 00:00 | 10:08:39.15 | +50:44:10.0 | HIP 49727 | 6.88 |
| 2026-05-27 12:00 | 10:08:38.82 | +50:42:38.4 | HIP 49727 | 8.11 |
| 2026-05-28 00:00 | 10:08:38.58 | +50:41:06.6 | HIP 49727 | 9.42 |
| 2026-05-28 12:00 | 10:08:38.43 | +50:39:34.8 | HIP 49727 | 10.79 |
| 2026-05-29 00:00 | 10:08:38.38 | +50:38:02.9 | HIP 49727 | 12.19 |
| 2026-05-29 12:00 | 10:08:38.42 | +50:36:31.0 | HIP 49727 | 13.61 |
| 2026-05-30 00:00 | 10:08:38.55 | +50:34:58.9 | HIP 49727 | 15.05 |
| 2026-05-30 12:00 | 10:08:38.78 | +50:33:26.8 | HIP 49727 | 16.51 |
| 2026-05-31 00:00 | 10:08:39.10 | +50:31:54.7 | HIP 49727 | 17.97 |
| 2026-05-31 12:00 | 10:08:39.50 | +50:30:22.4 | HIP 49727 | 19.45 |
| 2026-06-01 00:00 | 10:08:40.00 | +50:28:50.2 | HIP 49727 | 20.93 |
| 2026-06-01 12:00 | 10:08:40.59 | +50:27:17.9 | HIP 49727 | 22.41 |
| 2026-06-02 00:00 | 10:08:41.27 | +50:25:45.5 | HIP 49727 | 23.91 |