P/2020 A4 (PANSTARRS-Lemmon)
メタデータ
| 項目 |
値 |
| Designation |
P/2020 A4 (PANSTARRS-Lemmon) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2019-11-22T17:20:48.589440Z |
| Orbit solution date (soln_date, UTC) |
2022-08-07T20:12:03Z |
| Obs used |
106 |
| NEO |
- |
| M1 |
15.600 |
| K1 |
8.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-01-01T12:06:58.176000Z |
| Discovery magnitude (MPC) |
21.40 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2020-02-03.0000000 |
| e |
0.65370445 |
| q (au) |
2.842514 |
| a (au) |
8.208347 |
| i (deg) |
24.990302 |
| Ω (om, deg) |
312.429623 |
| ω (w, deg) |
144.883054 |
| M (ma, deg) |
3.029158 |
等級
散乱 + 全体線形
$$
M_a = (17.586 + 3.081\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
17.586 |
| n |
3.081 |
| gf |
1.000 |
| gb |
-0.590 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
16:55:27.43 |
-43:38:20.6 |
HIP 82740 |
9.53 |
| 2026-02-03 12:00 |
16:55:37.24 |
-43:39:12.0 |
HIP 82740 |
11.50 |
| 2026-02-04 00:00 |
16:55:46.95 |
-43:40:03.5 |
HIP 82740 |
13.45 |
| 2026-02-04 12:00 |
16:55:56.57 |
-43:40:55.1 |
HIP 82740 |
15.39 |
| 2026-02-05 00:00 |
16:56:06.10 |
-43:41:46.8 |
HIP 82917 |
16.23 |
| 2026-02-05 12:00 |
16:56:15.54 |
-43:42:38.6 |
HIP 82917 |
14.86 |
| 2026-02-06 00:00 |
16:56:24.88 |
-43:43:30.6 |
HIP 82917 |
13.61 |
| 2026-02-06 12:00 |
16:56:34.13 |
-43:44:22.7 |
HIP 82917 |
12.52 |
| 2026-02-07 00:00 |
16:56:43.29 |
-43:45:14.9 |
HIP 82917 |
11.64 |
| 2026-02-07 12:00 |
16:56:52.35 |
-43:46:07.2 |
HIP 83011 |
10.06 |
| 2026-02-08 00:00 |
16:57:01.32 |
-43:46:59.6 |
HIP 83011 |
8.33 |
| 2026-02-08 12:00 |
16:57:10.19 |
-43:47:52.1 |
HIP 83011 |
6.68 |
| 2026-02-09 00:00 |
16:57:18.96 |
-43:48:44.7 |
HIP 83011 |
5.15 |
| 2026-02-09 12:00 |
16:57:27.64 |
-43:49:37.4 |
HIP 83011 |
3.90 |
| 2026-02-10 00:00 |
16:57:36.22 |
-43:50:30.2 |
HIP 83011 |
3.23 |
| 2026-02-10 12:00 |
16:57:44.70 |
-43:51:23.2 |
HIP 83011 |
3.46 |
| 2026-02-11 00:00 |
16:57:53.08 |
-43:52:16.2 |
HIP 83011 |
4.45 |
| 2026-02-11 12:00 |
16:58:01.37 |
-43:53:09.3 |
HIP 83011 |
5.80 |
| 2026-02-12 00:00 |
16:58:09.55 |
-43:54:02.5 |
HIP 83011 |
7.30 |
| 2026-02-12 12:00 |
16:58:17.63 |
-43:54:55.7 |
HIP 83011 |
8.88 |
| 2026-02-13 00:00 |
16:58:25.61 |
-43:55:49.1 |
HIP 83011 |
10.48 |
| 2026-02-13 12:00 |
16:58:33.48 |
-43:56:42.5 |
HIP 83011 |
12.10 |
| 2026-02-14 00:00 |
16:58:41.26 |
-43:57:36.1 |
HIP 83011 |
13.71 |
| 2026-02-14 12:00 |
16:58:48.93 |
-43:58:29.7 |
HIP 83169 |
13.11 |
| 2026-02-15 00:00 |
16:58:56.49 |
-43:59:23.3 |
HIP 83169 |
12.53 |
| 2026-02-15 12:00 |
16:59:03.96 |
-44:00:17.1 |
HIP 83169 |
12.16 |
| 2026-02-16 00:00 |
16:59:11.31 |
-44:01:10.9 |
HIP 83169 |
12.01 |
| 2026-02-16 12:00 |
16:59:18.56 |
-44:02:04.8 |
HIP 83169 |
12.08 |
| 2026-02-17 00:00 |
16:59:25.70 |
-44:02:58.7 |
HIP 83169 |
12.36 |
| 2026-02-17 12:00 |
16:59:32.74 |
-44:03:52.7 |
HIP 83169 |
12.84 |
| 2026-02-18 00:00 |
16:59:39.67 |
-44:04:46.8 |
HIP 83169 |
13.48 |
| 2026-02-18 12:00 |
16:59:46.49 |
-44:05:40.9 |
HIP 83169 |
14.26 |
| 2026-02-19 00:00 |
16:59:53.20 |
-44:06:35.0 |
HIP 83169 |
15.16 |
| 2026-02-19 12:00 |
16:59:59.80 |
-44:07:29.3 |
HIP 83169 |
16.14 |
| 2026-02-20 00:00 |
17:00:06.30 |
-44:08:23.5 |
HIP 83169 |
17.20 |
| 2026-02-20 12:00 |
17:00:12.68 |
-44:09:17.8 |
HIP 83169 |
18.31 |
| 2026-02-21 00:00 |
17:00:18.95 |
-44:10:12.1 |
HIP 83169 |
19.46 |
| 2026-02-21 12:00 |
17:00:25.11 |
-44:11:06.5 |
HIP 83169 |
20.65 |
| 2026-02-22 00:00 |
17:00:31.16 |
-44:12:00.9 |
HIP 83169 |
21.85 |
| 2026-02-22 12:00 |
17:00:37.10 |
-44:12:55.3 |
HIP 83330 |
22.49 |
| 2026-02-23 00:00 |
17:00:42.92 |
-44:13:49.8 |
HIP 83330 |
21.14 |
| 2026-02-23 12:00 |
17:00:48.64 |
-44:14:44.2 |
HIP 83330 |
19.82 |
| 2026-02-24 00:00 |
17:00:54.23 |
-44:15:38.7 |
HIP 83330 |
18.51 |