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 |
-32.4269 |
+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) |
| 2026-09-20 00:00 |
16:10:30.26 |
-31:32:52.3 |
HIP 79198 |
8.84 |
| 2026-09-20 12:00 |
16:10:37.80 |
-31:32:11.3 |
HIP 79198 |
10.59 |
| 2026-09-21 00:00 |
16:10:45.44 |
-31:31:30.8 |
HIP 79198 |
12.35 |
| 2026-09-21 12:00 |
16:10:53.17 |
-31:30:50.7 |
HIP 79198 |
14.13 |
| 2026-09-22 00:00 |
16:11:01.00 |
-31:30:11.0 |
HIP 79198 |
15.92 |
| 2026-09-22 12:00 |
16:11:08.92 |
-31:29:31.9 |
HIP 79198 |
17.74 |
| 2026-09-23 00:00 |
16:11:16.94 |
-31:28:53.2 |
HIP 79198 |
19.56 |
| 2026-09-23 12:00 |
16:11:25.06 |
-31:28:14.9 |
HIP 79198 |
21.40 |
| 2026-09-24 00:00 |
16:11:33.26 |
-31:27:37.1 |
HIP 79198 |
23.26 |
| 2026-09-24 12:00 |
16:11:41.56 |
-31:26:59.8 |
HIP 79198 |
25.14 |
| 2026-09-25 00:00 |
16:11:49.95 |
-31:26:22.9 |
HIP 79198 |
27.03 |
| 2026-09-25 12:00 |
16:11:58.43 |
-31:25:46.4 |
HIP 79201 |
28.88 |
| 2026-09-26 00:00 |
16:12:07.00 |
-31:25:10.4 |
HIP 79201 |
30.36 |
| 2026-09-26 12:00 |
16:12:15.66 |
-31:24:34.8 |
HIP 79578 |
29.08 |
| 2026-09-27 00:00 |
16:12:24.41 |
-31:23:59.7 |
HIP 79578 |
27.83 |
| 2026-09-27 12:00 |
16:12:33.24 |
-31:23:25.0 |
HIP 79578 |
26.66 |
| 2026-09-28 00:00 |
16:12:42.17 |
-31:22:50.7 |
HIP 79578 |
25.56 |
| 2026-09-28 12:00 |
16:12:51.18 |
-31:22:16.9 |
HIP 79578 |
24.55 |
| 2026-09-29 00:00 |
16:13:00.28 |
-31:21:43.5 |
HIP 79578 |
23.66 |
| 2026-09-29 12:00 |
16:13:09.46 |
-31:21:10.6 |
HIP 79578 |
22.89 |
| 2026-09-30 00:00 |
16:13:18.73 |
-31:20:38.0 |
HIP 79578 |
22.26 |
| 2026-09-30 12:00 |
16:13:28.08 |
-31:20:05.9 |
HIP 79578 |
21.80 |
| 2026-10-01 00:00 |
16:13:37.51 |
-31:19:34.2 |
HIP 79578 |
21.51 |
| 2026-10-01 12:00 |
16:13:47.03 |
-31:19:03.0 |
HIP 79578 |
21.40 |
| 2026-10-02 00:00 |
16:13:56.63 |
-31:18:32.1 |
HIP 79578 |
21.50 |
| 2026-10-02 12:00 |
16:14:06.31 |
-31:18:01.7 |
HIP 79578 |
21.79 |
| 2026-10-03 00:00 |
16:14:16.08 |
-31:17:31.7 |
HIP 79578 |
22.27 |
| 2026-10-03 12:00 |
16:14:25.92 |
-31:17:02.1 |
HIP 79578 |
22.94 |
| 2026-10-04 00:00 |
16:14:35.84 |
-31:16:32.9 |
HIP 79578 |
23.78 |
| 2026-10-04 12:00 |
16:14:45.85 |
-31:16:04.1 |
HIP 79578 |
24.79 |
| 2026-10-05 00:00 |
16:14:55.93 |
-31:15:35.8 |
HIP 79578 |
25.94 |
| 2026-10-05 12:00 |
16:15:06.09 |
-31:15:07.8 |
HIP 79578 |
27.22 |
| 2026-10-06 00:00 |
16:15:16.32 |
-31:14:40.2 |
HIP 79578 |
28.62 |
| 2026-10-06 12:00 |
16:15:26.64 |
-31:14:13.1 |
HIP 79578 |
30.12 |
| 2026-10-07 00:00 |
16:15:37.03 |
-31:13:46.3 |
HIP 79578 |
31.71 |
| 2026-10-07 12:00 |
16:15:47.49 |
-31:13:20.0 |
HIP 79731 |
32.07 |
| 2026-10-08 00:00 |
16:15:58.03 |
-31:12:54.0 |
HIP 79731 |
31.23 |
| 2026-10-08 12:00 |
16:16:08.64 |
-31:12:28.4 |
HIP 79731 |
30.53 |
| 2026-10-09 00:00 |
16:16:19.33 |
-31:12:03.3 |
HIP 79731 |
30.01 |
| 2026-10-09 12:00 |
16:16:30.09 |
-31:11:38.5 |
HIP 79731 |
29.67 |
| 2026-10-10 00:00 |
16:16:40.92 |
-31:11:14.0 |
HIP 79731 |
29.52 |
| 2026-10-10 12:00 |
16:16:51.82 |
-31:10:50.0 |
HIP 79731 |
29.57 |
| 2026-10-11 00:00 |
16:17:02.79 |
-31:10:26.4 |
HIP 79731 |
29.82 |