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
$$
M_a = (5.999 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
5.999 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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 |
-97.1894 |
+76.977 |
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) |
| 2026-03-26 00:00 |
06:53:58.63 |
+22:47:07.7 |
HIP 33097 |
5.11 |
| 2026-03-26 12:00 |
06:54:04.33 |
+22:46:57.1 |
HIP 33097 |
6.41 |
| 2026-03-27 00:00 |
06:54:10.19 |
+22:46:46.2 |
HIP 33097 |
7.75 |
| 2026-03-27 12:00 |
06:54:16.22 |
+22:46:35.1 |
HIP 33097 |
9.14 |
| 2026-03-28 00:00 |
06:54:22.40 |
+22:46:23.8 |
HIP 33097 |
10.56 |
| 2026-03-28 12:00 |
06:54:28.75 |
+22:46:12.3 |
HIP 33097 |
12.03 |
| 2026-03-29 00:00 |
06:54:35.25 |
+22:46:00.6 |
HIP 33097 |
13.54 |
| 2026-03-29 12:00 |
06:54:41.92 |
+22:45:48.7 |
HIP 33251 |
13.25 |
| 2026-03-30 00:00 |
06:54:48.74 |
+22:45:36.5 |
HIP 33251 |
12.52 |
| 2026-03-30 12:00 |
06:54:55.72 |
+22:45:24.1 |
HIP 33251 |
11.95 |
| 2026-03-31 00:00 |
06:55:02.85 |
+22:45:11.5 |
HIP 33251 |
11.58 |
| 2026-03-31 12:00 |
06:55:10.14 |
+22:44:58.7 |
HIP 33251 |
11.43 |
| 2026-04-01 00:00 |
06:55:17.59 |
+22:44:45.7 |
HIP 33251 |
11.55 |
| 2026-04-01 12:00 |
06:55:25.19 |
+22:44:32.5 |
HIP 33251 |
11.92 |
| 2026-04-02 00:00 |
06:55:32.94 |
+22:44:19.0 |
HIP 33251 |
12.56 |
| 2026-04-02 12:00 |
06:55:40.85 |
+22:44:05.3 |
HIP 33251 |
13.42 |
| 2026-04-03 00:00 |
06:55:48.91 |
+22:43:51.4 |
HIP 33251 |
14.49 |
| 2026-04-03 12:00 |
06:55:57.12 |
+22:43:37.3 |
HIP 33251 |
15.74 |
| 2026-04-04 00:00 |
06:56:05.48 |
+22:43:23.0 |
HIP 33251 |
17.14 |
| 2026-04-04 12:00 |
06:56:13.99 |
+22:43:08.4 |
HIP 33251 |
18.66 |
| 2026-04-05 00:00 |
06:56:22.65 |
+22:42:53.7 |
HIP 33251 |
20.29 |
| 2026-04-05 12:00 |
06:56:31.46 |
+22:42:38.7 |
HIP 33497 |
20.44 |
| 2026-04-06 00:00 |
06:56:40.42 |
+22:42:23.5 |
HIP 33497 |
18.88 |
| 2026-04-06 12:00 |
06:56:49.53 |
+22:42:08.0 |
HIP 33497 |
17.40 |
| 2026-04-07 00:00 |
06:56:58.78 |
+22:41:52.4 |
HIP 33497 |
16.05 |
| 2026-04-07 12:00 |
06:57:08.18 |
+22:41:36.5 |
HIP 33497 |
14.86 |
| 2026-04-08 00:00 |
06:57:17.73 |
+22:41:20.4 |
HIP 33497 |
13.91 |
| 2026-04-08 12:00 |
06:57:27.42 |
+22:41:04.0 |
HIP 33497 |
13.25 |
| 2026-04-09 00:00 |
06:57:37.25 |
+22:40:47.4 |
HIP 33497 |
12.96 |
| 2026-04-09 12:00 |
06:57:47.23 |
+22:40:30.7 |
HIP 33497 |
13.06 |
| 2026-04-10 00:00 |
06:57:57.35 |
+22:40:13.6 |
HIP 33537 |
12.15 |
| 2026-04-10 12:00 |
06:58:07.62 |
+22:39:56.4 |
HIP 33537 |
11.44 |
| 2026-04-11 00:00 |
06:58:18.02 |
+22:39:38.9 |
HIP 33537 |
11.20 |
| 2026-04-11 12:00 |
06:58:28.57 |
+22:39:21.2 |
HIP 33537 |
11.49 |
| 2026-04-12 00:00 |
06:58:39.26 |
+22:39:03.2 |
HIP 33537 |
12.29 |
| 2026-04-12 12:00 |
06:58:50.08 |
+22:38:45.1 |
HIP 33537 |
13.52 |
| 2026-04-13 00:00 |
06:59:01.05 |
+22:38:26.6 |
HIP 33537 |
15.09 |
| 2026-04-13 12:00 |
06:59:12.15 |
+22:38:08.0 |
HIP 33537 |
16.93 |
| 2026-04-14 00:00 |
06:59:23.39 |
+22:37:49.1 |
HIP 33537 |
18.97 |
| 2026-04-14 12:00 |
06:59:34.77 |
+22:37:30.0 |
HIP 33537 |
21.17 |
| 2026-04-15 00:00 |
06:59:46.28 |
+22:37:10.6 |
HIP 33656 |
22.64 |
| 2026-04-15 12:00 |
06:59:57.93 |
+22:36:51.0 |
HIP 33656 |
22.88 |
| 2026-04-16 00:00 |
07:00:09.71 |
+22:36:31.2 |
HIP 33656 |
23.45 |