メタデータ
| 項目 |
値 |
| Designation |
2P/Encke |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2023-10-22T12:13:02.507520Z |
| Orbit solution date (soln_date, UTC) |
2026-09-21T09:56:43Z |
| Obs used |
800 |
| NEO |
Yes |
| M1 |
15.700 |
| 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) |
2023-04-28.0000000 |
| e |
0.84702790 |
| q (au) |
0.339482 |
| a (au) |
2.219243 |
| i (deg) |
11.342270 |
| Ω (om, deg) |
334.045469 |
| ω (w, deg) |
187.263043 |
| M (ma, deg) |
307.080292 |
等級
散乱 + 全体線形
$$
M_a = (17.234 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
17.234 |
| n |
2.000 |
| gf |
0.996 |
| gb |
-0.802 |
| k |
0.948 |
| δ90 |
9.999 |
| 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
ファインディングチャート
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
01:10:10.14 |
+20:28:55.4 |
HIP 5310 |
34.75 |
| 2026-09-20 12:00 |
01:09:24.95 |
+20:28:45.0 |
HIP 5310 |
25.81 |
| 2026-09-21 00:00 |
01:08:38.98 |
+20:28:30.0 |
HIP 5285 |
15.55 |
| 2026-09-21 12:00 |
01:07:52.24 |
+20:28:10.5 |
HIP 5285 |
6.67 |
| 2026-09-22 00:00 |
01:07:04.72 |
+20:27:46.4 |
HIP 5285 |
9.51 |
| 2026-09-22 12:00 |
01:06:16.42 |
+20:27:17.5 |
HIP 5285 |
19.80 |
| 2026-09-23 00:00 |
01:05:27.34 |
+20:26:43.9 |
HIP 5248 |
29.33 |
| 2026-09-23 12:00 |
01:04:37.48 |
+20:26:05.3 |
HIP 4927 |
28.19 |
| 2026-09-24 00:00 |
01:03:46.85 |
+20:25:21.9 |
HIP 4927 |
20.99 |
| 2026-09-24 12:00 |
01:02:55.45 |
+20:24:33.4 |
HIP 4927 |
19.18 |
| 2026-09-25 00:00 |
01:02:03.27 |
+20:23:39.8 |
HIP 4715 |
21.98 |
| 2026-09-25 12:00 |
01:01:10.32 |
+20:22:41.1 |
HIP 4715 |
10.10 |
| 2026-09-26 00:00 |
01:00:16.60 |
+20:21:37.1 |
HIP 4715 |
5.62 |
| 2026-09-26 12:00 |
00:59:22.12 |
+20:20:27.7 |
HIP 4596 |
14.20 |
| 2026-09-27 00:00 |
00:58:26.88 |
+20:19:13.0 |
HIP 4596 |
14.54 |
| 2026-09-27 12:00 |
00:57:30.87 |
+20:17:52.7 |
HIP 4596 |
23.85 |
| 2026-09-28 00:00 |
00:56:34.11 |
+20:16:26.9 |
HIP 4316 |
18.71 |
| 2026-09-28 12:00 |
00:55:36.61 |
+20:14:55.4 |
HIP 4316 |
6.05 |
| 2026-09-29 00:00 |
00:54:38.35 |
+20:13:18.3 |
HIP 4316 |
9.77 |
| 2026-09-29 12:00 |
00:53:39.36 |
+20:11:35.3 |
HIP 4243 |
9.77 |
| 2026-09-30 00:00 |
00:52:39.63 |
+20:09:46.5 |
HIP 4243 |
21.62 |
| 2026-09-30 12:00 |
00:51:39.17 |
+20:07:51.7 |
HIP 4061 |
27.56 |
| 2026-10-01 00:00 |
00:50:37.99 |
+20:05:51.0 |
HIP 3855 |
19.13 |
| 2026-10-01 12:00 |
00:49:36.09 |
+20:03:44.2 |
HIP 3855 |
4.48 |
| 2026-10-02 00:00 |
00:48:33.50 |
+20:01:31.2 |
HIP 3855 |
10.47 |
| 2026-10-02 12:00 |
00:47:30.20 |
+19:59:12.0 |
HIP 3636 |
18.38 |
| 2026-10-03 00:00 |
00:46:26.21 |
+19:56:46.6 |
HIP 3636 |
16.20 |
| 2026-10-03 12:00 |
00:45:21.55 |
+19:54:14.9 |
HIP 3636 |
25.68 |
| 2026-10-04 00:00 |
00:44:16.22 |
+19:51:36.8 |
HIP 3502 |
35.82 |
| 2026-10-04 12:00 |
00:43:10.23 |
+19:48:52.3 |
HIP 3272 |
28.38 |
| 2026-10-05 00:00 |
00:42:03.60 |
+19:46:01.3 |
HIP 3272 |
22.79 |
| 2026-10-05 12:00 |
00:40:56.33 |
+19:43:03.8 |
HIP 3244 |
19.61 |
| 2026-10-06 00:00 |
00:39:48.44 |
+19:39:59.8 |
HIP 3014 |
20.66 |
| 2026-10-06 12:00 |
00:38:39.95 |
+19:36:49.1 |
HIP 3014 |
7.04 |
| 2026-10-07 00:00 |
00:37:30.87 |
+19:33:31.9 |
HIP 3014 |
14.75 |
| 2026-10-07 12:00 |
00:36:21.21 |
+19:30:08.0 |
HIP 3014 |
30.77 |
| 2026-10-08 00:00 |
00:35:10.99 |
+19:26:37.5 |
HIP 2730 |
32.88 |
| 2026-10-08 12:00 |
00:34:00.22 |
+19:23:00.2 |
HIP 2730 |
31.60 |
| 2026-10-09 00:00 |
00:32:48.92 |
+19:19:16.3 |
HIP 2502 |
18.21 |
| 2026-10-09 12:00 |
00:31:37.11 |
+19:15:25.7 |
HIP 2502 |
13.58 |
| 2026-10-10 00:00 |
00:30:24.81 |
+19:11:28.4 |
HIP 2412 |
8.77 |
| 2026-10-10 12:00 |
00:29:12.03 |
+19:07:24.4 |
HIP 2316 |
7.24 |
| 2026-10-11 00:00 |
00:27:58.79 |
+19:03:13.7 |
HIP 2316 |
22.20 |