メタデータ
| 項目 |
値 |
| Designation |
P/2018 A5 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2017-09-23T19:44:28.916160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:40Z |
| Obs used |
36 |
| NEO |
- |
| M1 |
17.700 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-12-11.0000000 |
| e |
0.52304780 |
| q (au) |
2.693821 |
| a (au) |
5.647990 |
| i (deg) |
23.577029 |
| Ω (om, deg) |
87.829721 |
| ω (w, deg) |
359.679511 |
| M (ma, deg) |
5.740433 |
等級
散乱 + 全体線形
$$
M_a = (17.815 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
17.815 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-1.000 |
| k |
0.999 |
| δ90 |
1.000 |
| 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 |
19:13:14.31 |
-32:18:41.5 |
HIP 94595 |
23.44 |
| 2026-07-29 12:00 |
19:13:00.64 |
-32:19:14.1 |
HIP 94595 |
26.11 |
| 2026-07-30 00:00 |
19:12:47.04 |
-32:19:46.0 |
HIP 94217 |
25.29 |
| 2026-07-30 12:00 |
19:12:33.49 |
-32:20:17.5 |
HIP 94217 |
22.39 |
| 2026-07-31 00:00 |
19:12:20.01 |
-32:20:48.4 |
HIP 94217 |
19.49 |
| 2026-07-31 12:00 |
19:12:06.59 |
-32:21:18.7 |
HIP 94217 |
16.62 |
| 2026-08-01 00:00 |
19:11:53.24 |
-32:21:48.5 |
HIP 94217 |
13.76 |
| 2026-08-01 12:00 |
19:11:39.96 |
-32:22:17.8 |
HIP 94217 |
10.91 |
| 2026-08-02 00:00 |
19:11:26.75 |
-32:22:46.5 |
HIP 94217 |
8.09 |
| 2026-08-02 12:00 |
19:11:13.60 |
-32:23:14.7 |
HIP 94217 |
5.29 |
| 2026-08-03 00:00 |
19:11:00.53 |
-32:23:42.4 |
HIP 94217 |
2.53 |
| 2026-08-03 12:00 |
19:10:47.54 |
-32:24:09.5 |
HIP 94217 |
0.68 |
| 2026-08-04 00:00 |
19:10:34.62 |
-32:24:36.1 |
HIP 94217 |
3.14 |
| 2026-08-04 12:00 |
19:10:21.77 |
-32:25:02.1 |
HIP 94217 |
5.86 |
| 2026-08-05 00:00 |
19:10:09.01 |
-32:25:27.6 |
HIP 94217 |
8.58 |
| 2026-08-05 12:00 |
19:09:56.33 |
-32:25:52.6 |
HIP 94217 |
11.28 |
| 2026-08-06 00:00 |
19:09:43.73 |
-32:26:17.0 |
HIP 94217 |
13.97 |
| 2026-08-06 12:00 |
19:09:31.21 |
-32:26:40.9 |
HIP 94217 |
16.63 |
| 2026-08-07 00:00 |
19:09:18.78 |
-32:27:04.2 |
HIP 93981 |
15.48 |
| 2026-08-07 12:00 |
19:09:06.43 |
-32:27:27.0 |
HIP 93981 |
12.85 |
| 2026-08-08 00:00 |
19:08:54.18 |
-32:27:49.3 |
HIP 93981 |
10.25 |
| 2026-08-08 12:00 |
19:08:42.01 |
-32:28:11.1 |
HIP 93981 |
7.67 |
| 2026-08-09 00:00 |
19:08:29.94 |
-32:28:32.3 |
HIP 93981 |
5.13 |
| 2026-08-09 12:00 |
19:08:17.96 |
-32:28:53.0 |
HIP 93981 |
2.67 |
| 2026-08-10 00:00 |
19:08:06.07 |
-32:29:13.1 |
HIP 93981 |
0.96 |
| 2026-08-10 12:00 |
19:07:54.28 |
-32:29:32.8 |
HIP 93964 |
1.48 |
| 2026-08-11 00:00 |
19:07:42.59 |
-32:29:51.9 |
HIP 93964 |
3.35 |
| 2026-08-11 12:00 |
19:07:31.00 |
-32:30:10.4 |
HIP 93964 |
5.69 |
| 2026-08-12 00:00 |
19:07:19.51 |
-32:30:28.5 |
HIP 93911 |
6.51 |
| 2026-08-12 12:00 |
19:07:08.12 |
-32:30:46.0 |
HIP 93911 |
7.25 |
| 2026-08-13 00:00 |
19:06:56.84 |
-32:31:03.0 |
HIP 93911 |
8.60 |
| 2026-08-13 12:00 |
19:06:45.66 |
-32:31:19.5 |
HIP 93911 |
10.33 |
| 2026-08-14 00:00 |
19:06:34.59 |
-32:31:35.5 |
HIP 93911 |
12.24 |
| 2026-08-14 12:00 |
19:06:23.63 |
-32:31:50.9 |
HIP 93911 |
14.27 |
| 2026-08-15 00:00 |
19:06:12.78 |
-32:32:05.9 |
HIP 93911 |
16.35 |
| 2026-08-15 12:00 |
19:06:02.03 |
-32:32:20.3 |
HIP 93911 |
18.45 |
| 2026-08-16 00:00 |
19:05:51.41 |
-32:32:34.3 |
HIP 93911 |
20.57 |
| 2026-08-16 12:00 |
19:05:40.89 |
-32:32:47.7 |
HIP 93911 |
22.69 |
| 2026-08-17 00:00 |
19:05:30.49 |
-32:33:00.6 |
HIP 93911 |
24.81 |
| 2026-08-17 12:00 |
19:05:20.20 |
-32:33:13.0 |
HIP 93911 |
26.91 |
| 2026-08-18 00:00 |
19:05:10.04 |
-32:33:25.0 |
HIP 93742 |
27.71 |
| 2026-08-18 12:00 |
19:04:59.99 |
-32:33:36.4 |
HIP 93742 |
27.73 |
| 2026-08-19 00:00 |
19:04:50.06 |
-32:33:47.3 |
HIP 93742 |
27.92 |