メタデータ
| 項目 |
値 |
| Designation |
39P/Oterma |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2023-04-09T06:48:51.543360Z |
| Orbit solution date (soln_date, UTC) |
2024-01-16T15:22:33Z |
| Obs used |
287 |
| NEO |
- |
| M1 |
6.800 |
| K1 |
14.750 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2014-12-03.0000000 |
| e |
0.22841232 |
| q (au) |
5.712314 |
| a (au) |
7.403325 |
| i (deg) |
1.478237 |
| Ω (om, deg) |
303.635589 |
| ω (w, deg) |
89.704331 |
| M (ma, deg) |
210.802445 |
等級
散乱 + 全体線形
$$
M_a = (7.853 + 5.174\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
7.853 |
| n |
5.174 |
| 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 |
| 2019-02-11 |
2022-08-03 |
-95.1181 |
+75.118 |
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) |
| 2026-09-20 00:00 |
08:45:50.43 |
+17:37:09.5 |
HIP 43079 |
11.90 |
| 2026-09-20 12:00 |
08:46:07.98 |
+17:35:56.8 |
HIP 43079 |
8.04 |
| 2026-09-21 00:00 |
08:46:25.44 |
+17:34:44.3 |
HIP 43079 |
5.08 |
| 2026-09-21 12:00 |
08:46:42.81 |
+17:33:32.0 |
HIP 43079 |
4.93 |
| 2026-09-22 00:00 |
08:47:00.10 |
+17:32:19.9 |
HIP 43079 |
7.74 |
| 2026-09-22 12:00 |
08:47:17.31 |
+17:31:08.1 |
HIP 43079 |
11.48 |
| 2026-09-23 00:00 |
08:47:34.43 |
+17:29:56.4 |
HIP 43206 |
9.85 |
| 2026-09-23 12:00 |
08:47:51.47 |
+17:28:44.9 |
HIP 43206 |
6.18 |
| 2026-09-24 00:00 |
08:48:08.42 |
+17:27:33.7 |
HIP 43206 |
3.90 |
| 2026-09-24 12:00 |
08:48:25.28 |
+17:26:22.7 |
HIP 43206 |
5.25 |
| 2026-09-25 00:00 |
08:48:42.05 |
+17:25:12.0 |
HIP 43206 |
8.65 |
| 2026-09-25 12:00 |
08:48:58.74 |
+17:24:01.4 |
HIP 43206 |
12.50 |
| 2026-09-26 00:00 |
08:49:15.33 |
+17:22:51.1 |
HIP 43206 |
16.48 |
| 2026-09-26 12:00 |
08:49:31.84 |
+17:21:41.1 |
HIP 43206 |
20.49 |
| 2026-09-27 00:00 |
08:49:48.26 |
+17:20:31.2 |
HIP 43412 |
21.48 |
| 2026-09-27 12:00 |
08:50:04.58 |
+17:19:21.7 |
HIP 43412 |
18.74 |
| 2026-09-28 00:00 |
08:50:20.82 |
+17:18:12.4 |
HIP 43412 |
16.55 |
| 2026-09-28 12:00 |
08:50:36.96 |
+17:17:03.3 |
HIP 43412 |
15.16 |
| 2026-09-29 00:00 |
08:50:53.01 |
+17:15:54.5 |
HIP 43412 |
14.76 |
| 2026-09-29 12:00 |
08:51:08.96 |
+17:14:46.0 |
HIP 43412 |
15.41 |
| 2026-09-30 00:00 |
08:51:24.83 |
+17:13:37.7 |
HIP 43412 |
16.99 |
| 2026-09-30 12:00 |
08:51:40.59 |
+17:12:29.7 |
HIP 43412 |
19.24 |
| 2026-10-01 00:00 |
08:51:56.26 |
+17:11:22.0 |
HIP 43635 |
21.04 |
| 2026-10-01 12:00 |
08:52:11.84 |
+17:10:14.6 |
HIP 43635 |
18.64 |
| 2026-10-02 00:00 |
08:52:27.32 |
+17:09:07.4 |
HIP 43635 |
16.81 |
| 2026-10-02 12:00 |
08:52:42.70 |
+17:08:00.6 |
HIP 43635 |
15.75 |
| 2026-10-03 00:00 |
08:52:57.98 |
+17:06:54.0 |
HIP 43635 |
15.58 |
| 2026-10-03 12:00 |
08:53:13.17 |
+17:05:47.8 |
HIP 43635 |
16.32 |
| 2026-10-04 00:00 |
08:53:28.25 |
+17:04:41.8 |
HIP 43635 |
17.85 |
| 2026-10-04 12:00 |
08:53:43.24 |
+17:03:36.2 |
HIP 43635 |
19.96 |
| 2026-10-05 00:00 |
08:53:58.12 |
+17:02:30.8 |
HIP 43635 |
22.48 |
| 2026-10-05 12:00 |
08:54:12.90 |
+17:01:25.8 |
HIP 43811 |
20.84 |
| 2026-10-06 00:00 |
08:54:27.58 |
+17:00:21.2 |
HIP 43811 |
18.91 |
| 2026-10-06 12:00 |
08:54:42.15 |
+16:59:16.8 |
HIP 43811 |
17.54 |
| 2026-10-07 00:00 |
08:54:56.62 |
+16:58:12.8 |
HIP 43811 |
16.87 |
| 2026-10-07 12:00 |
08:55:10.98 |
+16:57:09.1 |
HIP 43811 |
16.96 |
| 2026-10-08 00:00 |
08:55:25.24 |
+16:56:05.8 |
HIP 43811 |
17.79 |
| 2026-10-08 12:00 |
08:55:39.39 |
+16:55:02.9 |
HIP 43811 |
19.24 |
| 2026-10-09 00:00 |
08:55:53.43 |
+16:54:00.2 |
HIP 43811 |
21.17 |
| 2026-10-09 12:00 |
08:56:07.37 |
+16:52:58.0 |
HIP 43957 |
21.39 |
| 2026-10-10 00:00 |
08:56:21.19 |
+16:51:56.1 |
HIP 43957 |
20.14 |
| 2026-10-10 12:00 |
08:56:34.91 |
+16:50:54.6 |
HIP 43957 |
19.44 |
| 2026-10-11 00:00 |
08:56:48.52 |
+16:49:53.4 |
HIP 43957 |
19.33 |