C/2020 V2 (ZTF)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2020 V2 (ZTF) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2023-05-08T13:21:29.376000Z |
| Orbit solution date (soln_date, UTC) | 2025-09-30T13:39:21Z |
| Obs used | 5767 |
| NEO | - |
| M1 | 8.700 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2020-11-02T12:42:20.160000Z |
| Discovery magnitude (MPC) | 19.04 r |
| Discovery observatory (MPC) | I41 · Palomar Mountain–ZTF |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2022-10-07.0000000 |
| e | 1.00089953 |
| q (au) | 2.227960 |
| a (au) | -2476.803384 |
| i (deg) | 131.611042 |
| Ω (om, deg) | 212.371235 |
| ω (w, deg) | 162.424317 |
| M (ma, deg) | -0.001708 |
等級
散乱 + 全体線形
$$ M_a = (8.951 + 2.985\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 8.951 |
| n | 2.985 |
| gf | 1.000 |
| gb | -0.726 |
| k | 0.800 |
| δ90 | 10.000 |
| 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 |
|---|---|---|---|
| 2020-04-18 | 2022-11-29 | +2.8905 | -2.125 |
| 2022-11-29 | 2023-04-18 | +1.1777 | -1.001 |
| 2023-06-12 | 2023-08-25 | +25.9574 | -10.877 |
| 2023-08-25 | 2024-05-20 | -2.9823 | +1.312 |
| 2024-05-20 | 2025-10-26 | +0.5312 | -0.877 |
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) |
|---|---|---|---|---|
| 2026-06-01 00:00 | 19:51:11.65 | -71:47:25.0 | HIP 97644 | 2.47 |
| 2026-06-01 12:00 | 19:50:35.42 | -71:49:20.3 | HIP 97644 | 3.12 |
| 2026-06-02 00:00 | 19:49:58.84 | -71:51:14.4 | HIP 97644 | 6.06 |
| 2026-06-02 12:00 | 19:49:21.91 | -71:53:07.4 | HIP 97644 | 9.34 |
| 2026-06-03 00:00 | 19:48:44.63 | -71:54:59.2 | HIP 97644 | 12.70 |
| 2026-06-03 12:00 | 19:48:07.01 | -71:56:49.7 | HIP 97644 | 16.11 |
| 2026-06-04 00:00 | 19:47:29.04 | -71:58:39.0 | HIP 97644 | 19.53 |
| 2026-06-04 12:00 | 19:46:50.74 | -72:00:27.1 | HIP 97027 | 19.02 |
| 2026-06-05 00:00 | 19:46:12.10 | -72:02:13.9 | HIP 97027 | 17.29 |
| 2026-06-05 12:00 | 19:45:33.13 | -72:03:59.4 | HIP 96968 | 16.10 |
| 2026-06-06 00:00 | 19:44:53.82 | -72:05:43.6 | HIP 96968 | 12.62 |
| 2026-06-06 12:00 | 19:44:14.19 | -72:07:26.5 | HIP 96968 | 9.15 |
| 2026-06-07 00:00 | 19:43:34.23 | -72:09:08.0 | HIP 96968 | 5.69 |
| 2026-06-07 12:00 | 19:42:53.95 | -72:10:48.2 | HIP 96968 | 2.37 |
| 2026-06-08 00:00 | 19:42:13.35 | -72:12:26.9 | HIP 96968 | 1.87 |
| 2026-06-08 12:00 | 19:41:32.44 | -72:14:04.3 | HIP 96968 | 5.12 |
| 2026-06-09 00:00 | 19:40:51.22 | -72:15:40.2 | HIP 96764 | 4.80 |
| 2026-06-09 12:00 | 19:40:09.69 | -72:17:14.7 | HIP 96764 | 2.08 |
| 2026-06-10 00:00 | 19:39:27.86 | -72:18:47.8 | HIP 96764 | 3.27 |
| 2026-06-10 12:00 | 19:38:45.73 | -72:20:19.3 | HIP 96764 | 6.50 |
| 2026-06-11 00:00 | 19:38:03.30 | -72:21:49.4 | HIP 96764 | 9.95 |
| 2026-06-11 12:00 | 19:37:20.59 | -72:23:18.0 | HIP 96764 | 13.46 |
| 2026-06-12 00:00 | 19:36:37.59 | -72:24:45.0 | HIP 96764 | 17.00 |
| 2026-06-12 12:00 | 19:35:54.31 | -72:26:10.5 | HIP 96764 | 20.55 |
| 2026-06-13 00:00 | 19:35:10.75 | -72:27:34.4 | HIP 96289 | 20.28 |
| 2026-06-13 12:00 | 19:34:26.92 | -72:28:56.7 | HIP 96289 | 18.82 |
| 2026-06-14 00:00 | 19:33:42.82 | -72:30:17.4 | HIP 96289 | 17.99 |
| 2026-06-14 12:00 | 19:32:58.47 | -72:31:36.5 | HIP 96289 | 17.86 |
| 2026-06-15 00:00 | 19:32:13.86 | -72:32:54.0 | HIP 96289 | 18.47 |
| 2026-06-15 12:00 | 19:31:29.00 | -72:34:09.9 | HIP 95712 | 17.90 |
| 2026-06-16 00:00 | 19:30:43.89 | -72:35:24.0 | HIP 95712 | 15.84 |
| 2026-06-16 12:00 | 19:29:58.55 | -72:36:36.5 | HIP 95712 | 14.37 |
| 2026-06-17 00:00 | 19:29:12.98 | -72:37:47.3 | HIP 95712 | 13.70 |
| 2026-06-17 12:00 | 19:28:27.18 | -72:38:56.4 | HIP 95712 | 13.93 |
| 2026-06-18 00:00 | 19:27:41.16 | -72:40:03.8 | HIP 95712 | 15.04 |
| 2026-06-18 12:00 | 19:26:54.92 | -72:41:09.4 | HIP 95704 | 16.80 |
| 2026-06-19 00:00 | 19:26:08.48 | -72:42:13.3 | HIP 95704 | 19.08 |
| 2026-06-19 12:00 | 19:25:21.84 | -72:43:15.5 | HIP 95100 | 21.02 |
| 2026-06-20 00:00 | 19:24:35.00 | -72:44:15.8 | HIP 95100 | 18.01 |
| 2026-06-20 12:00 | 19:23:47.98 | -72:45:14.4 | HIP 95100 | 15.26 |
| 2026-06-21 00:00 | 19:23:00.77 | -72:46:11.3 | HIP 95100 | 12.92 |
| 2026-06-21 12:00 | 19:22:13.39 | -72:47:06.3 | HIP 95100 | 11.27 |
| 2026-06-22 00:00 | 19:21:25.84 | -72:47:59.5 | HIP 95100 | 10.62 |