メタデータ
| 項目 |
値 |
| Designation |
400P/PANSTARRS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-02-09T22:37:16.553280Z |
| Orbit solution date (soln_date, UTC) |
2024-10-05T23:12:48Z |
| Obs used |
414 |
| NEO |
- |
| M1 |
13.800 |
| K1 |
12.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-09-10T09:07:24.096000Z |
| Discovery magnitude (MPC) |
19.20 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2020-02-27.0000000 |
| e |
0.40901297 |
| q (au) |
2.104108 |
| a (au) |
3.560329 |
| i (deg) |
10.926393 |
| Ω (om, deg) |
176.405371 |
| ω (w, deg) |
238.711384 |
| M (ma, deg) |
308.805563 |
等級
散乱 + 全体線形
$$
M_a = (11.776 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
11.776 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
1.000 |
| 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 |
| 2020-06-01 |
2020-08-29 |
+19.2128 |
-6.748 |
| 2020-08-29 |
2021-02-07 |
+8.6813 |
-3.045 |
| 2021-02-10 |
2022-02-24 |
+1.7883 |
-1.680 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
19:52:14.21 |
-08:07:32.3 |
HIP 97966 |
36.02 |
| 2026-07-29 12:00 |
19:51:51.91 |
-08:09:20.6 |
HIP 97600 |
35.85 |
| 2026-07-30 00:00 |
19:51:29.66 |
-08:11:09.8 |
HIP 97600 |
30.96 |
| 2026-07-30 12:00 |
19:51:07.46 |
-08:13:00.1 |
HIP 97600 |
26.44 |
| 2026-07-31 00:00 |
19:50:45.31 |
-08:14:51.3 |
HIP 97600 |
22.49 |
| 2026-07-31 12:00 |
19:50:23.23 |
-08:16:43.6 |
HIP 97600 |
19.47 |
| 2026-08-01 00:00 |
19:50:01.21 |
-08:18:36.7 |
HIP 97600 |
17.84 |
| 2026-08-01 12:00 |
19:49:39.25 |
-08:20:30.9 |
HIP 97600 |
17.98 |
| 2026-08-02 00:00 |
19:49:17.37 |
-08:22:25.9 |
HIP 97600 |
19.83 |
| 2026-08-02 12:00 |
19:48:55.57 |
-08:24:21.9 |
HIP 97488 |
22.02 |
| 2026-08-03 00:00 |
19:48:33.85 |
-08:26:18.8 |
HIP 97488 |
24.38 |
| 2026-08-03 12:00 |
19:48:12.22 |
-08:28:16.5 |
HIP 97350 |
24.84 |
| 2026-08-04 00:00 |
19:47:50.68 |
-08:30:15.1 |
HIP 97350 |
23.58 |
| 2026-08-04 12:00 |
19:47:29.23 |
-08:32:14.5 |
HIP 97350 |
23.66 |
| 2026-08-05 00:00 |
19:47:07.89 |
-08:34:14.7 |
HIP 97350 |
25.08 |
| 2026-08-05 12:00 |
19:46:46.65 |
-08:36:15.8 |
HIP 97173 |
25.74 |
| 2026-08-06 00:00 |
19:46:25.52 |
-08:38:17.6 |
HIP 97173 |
20.45 |
| 2026-08-06 12:00 |
19:46:04.50 |
-08:40:20.2 |
HIP 97173 |
15.41 |
| 2026-08-07 00:00 |
19:45:43.61 |
-08:42:23.5 |
HIP 97173 |
10.94 |
| 2026-08-07 12:00 |
19:45:22.84 |
-08:44:27.6 |
HIP 97173 |
8.02 |
| 2026-08-08 00:00 |
19:45:02.19 |
-08:46:32.4 |
HIP 97173 |
8.39 |
| 2026-08-08 12:00 |
19:44:41.68 |
-08:48:37.8 |
HIP 97173 |
11.71 |
| 2026-08-09 00:00 |
19:44:21.31 |
-08:50:44.0 |
HIP 97173 |
16.23 |
| 2026-08-09 12:00 |
19:44:01.08 |
-08:52:50.7 |
HIP 97065 |
13.02 |
| 2026-08-10 00:00 |
19:43:41.00 |
-08:54:58.1 |
HIP 97065 |
9.22 |
| 2026-08-10 12:00 |
19:43:21.07 |
-08:57:06.1 |
HIP 97065 |
7.65 |
| 2026-08-11 00:00 |
19:43:01.29 |
-08:59:14.7 |
HIP 97065 |
9.42 |
| 2026-08-11 12:00 |
19:42:41.68 |
-09:01:23.9 |
HIP 97065 |
13.22 |
| 2026-08-12 00:00 |
19:42:22.23 |
-09:03:33.6 |
HIP 96917 |
9.36 |
| 2026-08-12 12:00 |
19:42:02.95 |
-09:05:43.8 |
HIP 96917 |
5.88 |
| 2026-08-13 00:00 |
19:41:43.84 |
-09:07:54.5 |
HIP 96917 |
5.98 |
| 2026-08-13 12:00 |
19:41:24.91 |
-09:10:05.7 |
HIP 96917 |
9.50 |
| 2026-08-14 00:00 |
19:41:06.17 |
-09:12:17.3 |
HIP 96917 |
14.02 |
| 2026-08-14 12:00 |
19:40:47.61 |
-09:14:29.4 |
HIP 96917 |
18.80 |
| 2026-08-15 00:00 |
19:40:29.24 |
-09:16:41.9 |
HIP 96917 |
23.67 |
| 2026-08-15 12:00 |
19:40:11.06 |
-09:18:54.8 |
HIP 96917 |
28.55 |
| 2026-08-16 00:00 |
19:39:53.09 |
-09:21:08.0 |
HIP 96917 |
33.42 |
| 2026-08-16 12:00 |
19:39:35.31 |
-09:23:21.6 |
HIP 96917 |
38.26 |
| 2026-08-17 00:00 |
19:39:17.74 |
-09:25:35.6 |
HIP 96917 |
43.08 |
| 2026-08-17 12:00 |
19:39:00.38 |
-09:27:49.8 |
HIP 96435 |
39.77 |
| 2026-08-18 00:00 |
19:38:43.24 |
-09:30:04.3 |
HIP 96435 |
36.26 |
| 2026-08-18 12:00 |
19:38:26.31 |
-09:32:19.1 |
HIP 96435 |
33.12 |
| 2026-08-19 00:00 |
19:38:09.59 |
-09:34:34.1 |
HIP 96435 |
30.46 |