メタデータ
| 項目 |
値 |
| Designation |
12P/Pons-Brooks |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2024-04-21T03:08:52.180800Z |
| Orbit solution date (soln_date, UTC) |
2026-01-08T08:25:35Z |
| Obs used |
8059 |
| NEO |
Yes |
| M1 |
5.000 |
| K1 |
15.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2023-09-24.0000000 |
| e |
0.95456124 |
| q (au) |
0.780861 |
| a (au) |
17.184915 |
| i (deg) |
74.190910 |
| Ω (om, deg) |
255.855351 |
| ω (w, deg) |
198.987999 |
| M (ma, deg) |
357.092810 |
等級
散乱 + 全体線形
$$
M_a = (5.193 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
5.193 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.880 |
| k |
0.991 |
| 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 |
| 2020-06-10 |
2023-07-20 |
+7.5133 |
-5.467 |
| 2023-07-20 |
2023-08-30 |
-32.4270 |
+17.092 |
| 2023-08-30 |
2023-12-18 |
+0.8594 |
-0.954 |
| 2023-12-18 |
2024-04-20 |
-0.0616 |
+0.065 |
| 2024-04-21 |
2024-06-16 |
+0.4640 |
-0.450 |
| 2024-06-16 |
2024-10-11 |
-8.2592 |
+0.843 |
| 2024-10-11 |
2025-06-07 |
+15.5927 |
-9.537 |
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) |
| 2026-05-12 00:00 |
16:48:02.31 |
-37:06:00.5 |
HIP 82272 |
11.51 |
| 2026-05-12 12:00 |
16:47:43.94 |
-37:05:17.2 |
HIP 82272 |
14.54 |
| 2026-05-13 00:00 |
16:47:25.51 |
-37:04:33.1 |
HIP 82272 |
17.85 |
| 2026-05-13 12:00 |
16:47:07.02 |
-37:03:48.3 |
HIP 82272 |
21.32 |
| 2026-05-14 00:00 |
16:46:48.47 |
-37:03:02.7 |
HIP 82026 |
23.96 |
| 2026-05-14 12:00 |
16:46:29.87 |
-37:02:16.4 |
HIP 82026 |
21.97 |
| 2026-05-15 00:00 |
16:46:11.22 |
-37:01:29.2 |
HIP 82026 |
20.50 |
| 2026-05-15 12:00 |
16:45:52.51 |
-37:00:41.3 |
HIP 82026 |
19.67 |
| 2026-05-16 00:00 |
16:45:33.76 |
-36:59:52.6 |
HIP 82026 |
19.58 |
| 2026-05-16 12:00 |
16:45:14.96 |
-36:59:03.1 |
HIP 82026 |
20.23 |
| 2026-05-17 00:00 |
16:44:56.12 |
-36:58:12.8 |
HIP 82026 |
21.57 |
| 2026-05-17 12:00 |
16:44:37.24 |
-36:57:21.8 |
HIP 81921 |
20.54 |
| 2026-05-18 00:00 |
16:44:18.32 |
-36:56:30.0 |
HIP 81921 |
18.58 |
| 2026-05-18 12:00 |
16:43:59.37 |
-36:55:37.5 |
HIP 81921 |
17.27 |
| 2026-05-19 00:00 |
16:43:40.38 |
-36:54:44.1 |
HIP 81921 |
16.78 |
| 2026-05-19 12:00 |
16:43:21.36 |
-36:53:50.1 |
HIP 81803 |
15.10 |
| 2026-05-20 00:00 |
16:43:02.31 |
-36:52:55.2 |
HIP 81803 |
13.56 |
| 2026-05-20 12:00 |
16:42:43.24 |
-36:51:59.6 |
HIP 81803 |
13.06 |
| 2026-05-21 00:00 |
16:42:24.14 |
-36:51:03.2 |
HIP 81803 |
13.73 |
| 2026-05-21 12:00 |
16:42:05.02 |
-36:50:06.1 |
HIP 81682 |
15.40 |
| 2026-05-22 00:00 |
16:41:45.88 |
-36:49:08.2 |
HIP 81682 |
12.08 |
| 2026-05-22 12:00 |
16:41:26.72 |
-36:48:09.6 |
HIP 81682 |
9.25 |
| 2026-05-23 00:00 |
16:41:07.55 |
-36:47:10.3 |
HIP 81682 |
7.51 |
| 2026-05-23 12:00 |
16:40:48.36 |
-36:46:10.2 |
HIP 81682 |
7.66 |
| 2026-05-24 00:00 |
16:40:29.17 |
-36:45:09.3 |
HIP 81682 |
9.61 |
| 2026-05-24 12:00 |
16:40:09.96 |
-36:44:07.8 |
HIP 81682 |
12.55 |
| 2026-05-25 00:00 |
16:39:50.75 |
-36:43:05.5 |
HIP 81495 |
15.72 |
| 2026-05-25 12:00 |
16:39:31.54 |
-36:42:02.5 |
HIP 81475 |
12.69 |
| 2026-05-26 00:00 |
16:39:12.32 |
-36:40:58.7 |
HIP 81475 |
9.17 |
| 2026-05-26 12:00 |
16:38:53.11 |
-36:39:54.3 |
HIP 81475 |
6.26 |
| 2026-05-27 00:00 |
16:38:33.90 |
-36:38:49.1 |
HIP 81475 |
5.13 |
| 2026-05-27 12:00 |
16:38:14.69 |
-36:37:43.3 |
HIP 81475 |
6.75 |
| 2026-05-28 00:00 |
16:37:55.49 |
-36:36:36.7 |
HIP 81475 |
9.86 |
| 2026-05-28 12:00 |
16:37:36.29 |
-36:35:29.5 |
HIP 81475 |
13.45 |
| 2026-05-29 00:00 |
16:37:17.11 |
-36:34:21.5 |
HIP 81475 |
17.24 |
| 2026-05-29 12:00 |
16:36:57.94 |
-36:33:12.9 |
HIP 81475 |
21.11 |
| 2026-05-30 00:00 |
16:36:38.79 |
-36:32:03.6 |
HIP 81403 |
22.73 |
| 2026-05-30 12:00 |
16:36:19.66 |
-36:30:53.6 |
HIP 81403 |
23.89 |
| 2026-05-31 00:00 |
16:36:00.54 |
-36:29:42.9 |
HIP 81403 |
25.63 |
| 2026-05-31 12:00 |
16:35:41.45 |
-36:28:31.6 |
HIP 81197 |
25.83 |
| 2026-06-01 00:00 |
16:35:22.37 |
-36:27:19.6 |
HIP 81197 |
23.88 |
| 2026-06-01 12:00 |
16:35:03.33 |
-36:26:07.0 |
HIP 81197 |
22.47 |
| 2026-06-02 00:00 |
16:34:44.31 |
-36:24:53.7 |
HIP 81197 |
21.72 |