メタデータ
| 項目 |
値 |
| Designation |
P/2018 P4 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-11-07T08:17:57.094080Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:46Z |
| Obs used |
116 |
| NEO |
- |
| M1 |
11.600 |
| K1 |
10.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-08-08T12:01:59.232000Z |
| Discovery magnitude (MPC) |
20.60 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) |
2018-09-13.0000000 |
| e |
0.44931114 |
| q (au) |
3.666142 |
| a (au) |
6.657375 |
| i (deg) |
23.112765 |
| Ω (om, deg) |
353.110347 |
| ω (w, deg) |
8.115551 |
| M (ma, deg) |
356.824339 |
等級
散乱 + 全体線形
$$
M_a = (8.263 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.263 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.852 |
| k |
0.999 |
| 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) |
| 2026-07-29 00:00 |
11:19:54.34 |
+04:13:40.8 |
HIP 55327 |
12.35 |
| 2026-07-29 12:00 |
11:20:03.88 |
+04:12:22.7 |
HIP 55327 |
14.14 |
| 2026-07-30 00:00 |
11:20:13.47 |
+04:11:04.2 |
HIP 55327 |
16.20 |
| 2026-07-30 12:00 |
11:20:23.10 |
+04:09:45.5 |
HIP 55467 |
17.87 |
| 2026-07-31 00:00 |
11:20:32.79 |
+04:08:26.5 |
HIP 55467 |
15.77 |
| 2026-07-31 12:00 |
11:20:42.52 |
+04:07:07.1 |
HIP 55467 |
13.90 |
| 2026-08-01 00:00 |
11:20:52.29 |
+04:05:47.5 |
HIP 55467 |
12.36 |
| 2026-08-01 12:00 |
11:21:02.12 |
+04:04:27.6 |
HIP 55460 |
10.65 |
| 2026-08-02 00:00 |
11:21:11.98 |
+04:03:07.4 |
HIP 55460 |
8.12 |
| 2026-08-02 12:00 |
11:21:21.90 |
+04:01:46.9 |
HIP 55460 |
5.83 |
| 2026-08-03 00:00 |
11:21:31.86 |
+04:00:26.1 |
HIP 55460 |
4.24 |
| 2026-08-03 12:00 |
11:21:41.86 |
+03:59:05.1 |
HIP 55460 |
4.23 |
| 2026-08-04 00:00 |
11:21:51.91 |
+03:57:43.8 |
HIP 55460 |
5.84 |
| 2026-08-04 12:00 |
11:22:02.00 |
+03:56:22.2 |
HIP 55460 |
8.16 |
| 2026-08-05 00:00 |
11:22:12.13 |
+03:55:00.3 |
HIP 55460 |
10.76 |
| 2026-08-05 12:00 |
11:22:22.31 |
+03:53:38.1 |
HIP 55460 |
13.48 |
| 2026-08-06 00:00 |
11:22:32.53 |
+03:52:15.7 |
HIP 55460 |
16.27 |
| 2026-08-06 12:00 |
11:22:42.79 |
+03:50:53.1 |
HIP 55574 |
18.09 |
| 2026-08-07 00:00 |
11:22:53.09 |
+03:49:30.1 |
HIP 55574 |
18.93 |
| 2026-08-07 12:00 |
11:23:03.43 |
+03:48:06.9 |
HIP 55638 |
16.31 |
| 2026-08-08 00:00 |
11:23:13.82 |
+03:46:43.5 |
HIP 55638 |
13.47 |
| 2026-08-08 12:00 |
11:23:24.24 |
+03:45:19.7 |
HIP 55638 |
10.69 |
| 2026-08-09 00:00 |
11:23:34.71 |
+03:43:55.8 |
HIP 55638 |
8.01 |
| 2026-08-09 12:00 |
11:23:45.21 |
+03:42:31.5 |
HIP 55638 |
5.62 |
| 2026-08-10 00:00 |
11:23:55.75 |
+03:41:07.1 |
HIP 55638 |
4.09 |
| 2026-08-10 12:00 |
11:24:06.33 |
+03:39:42.4 |
HIP 55638 |
4.43 |
| 2026-08-11 00:00 |
11:24:16.95 |
+03:38:17.4 |
HIP 55638 |
6.37 |
| 2026-08-11 12:00 |
11:24:27.60 |
+03:36:52.2 |
HIP 55638 |
8.93 |
| 2026-08-12 00:00 |
11:24:38.29 |
+03:35:26.8 |
HIP 55638 |
11.72 |
| 2026-08-12 12:00 |
11:24:49.02 |
+03:34:01.1 |
HIP 55638 |
14.61 |
| 2026-08-13 00:00 |
11:24:59.78 |
+03:32:35.3 |
HIP 55638 |
17.56 |
| 2026-08-13 12:00 |
11:25:10.58 |
+03:31:09.1 |
HIP 55769 |
14.93 |
| 2026-08-14 00:00 |
11:25:21.41 |
+03:29:42.8 |
HIP 55769 |
12.48 |
| 2026-08-14 12:00 |
11:25:32.27 |
+03:28:16.3 |
HIP 55769 |
10.35 |
| 2026-08-15 00:00 |
11:25:43.17 |
+03:26:49.5 |
HIP 55769 |
8.80 |
| 2026-08-15 12:00 |
11:25:54.10 |
+03:25:22.5 |
HIP 55769 |
8.16 |
| 2026-08-16 00:00 |
11:26:05.07 |
+03:23:55.3 |
HIP 55769 |
8.66 |
| 2026-08-16 12:00 |
11:26:16.06 |
+03:22:27.9 |
HIP 55769 |
10.13 |
| 2026-08-17 00:00 |
11:26:27.09 |
+03:21:00.3 |
HIP 55769 |
12.24 |
| 2026-08-17 12:00 |
11:26:38.14 |
+03:19:32.5 |
HIP 55769 |
14.72 |
| 2026-08-18 00:00 |
11:26:49.23 |
+03:18:04.5 |
HIP 55846 |
17.34 |
| 2026-08-18 12:00 |
11:27:00.34 |
+03:16:36.3 |
HIP 55846 |
16.26 |
| 2026-08-19 00:00 |
11:27:11.49 |
+03:15:08.0 |
HIP 55846 |
15.74 |