メタデータ
| 項目 |
値 |
| Designation |
117P/Helin-Roman-Alu 1 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2014-03-27T04:27:16.583040Z |
| Orbit solution date (soln_date, UTC) |
2026-03-09T08:47:52Z |
| Obs used |
6500 |
| NEO |
- |
| M1 |
5.700 |
| K1 |
15.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2014-02-26.0000000 |
| e |
0.25383563 |
| q (au) |
3.056348 |
| a (au) |
4.096078 |
| i (deg) |
8.697534 |
| Ω (om, deg) |
58.898113 |
| ω (w, deg) |
222.686727 |
| M (ma, deg) |
356.530072 |
等級
散乱 + 全体線形
$$
M_a = (4.689 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
4.689 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.922 |
| k |
1.000 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
05:13:42.69 |
+27:28:05.4 |
HIP 24370 |
13.70 |
| 2026-03-26 12:00 |
05:13:58.59 |
+27:28:15.4 |
HIP 24370 |
14.17 |
| 2026-03-27 00:00 |
05:14:14.64 |
+27:28:25.6 |
HIP 24370 |
15.48 |
| 2026-03-27 12:00 |
05:14:30.86 |
+27:28:36.0 |
HIP 24370 |
17.45 |
| 2026-03-28 00:00 |
05:14:47.23 |
+27:28:46.5 |
HIP 24370 |
19.91 |
| 2026-03-28 12:00 |
05:15:03.75 |
+27:28:57.0 |
HIP 24370 |
22.72 |
| 2026-03-29 00:00 |
05:15:20.44 |
+27:29:07.8 |
HIP 24546 |
22.94 |
| 2026-03-29 12:00 |
05:15:37.27 |
+27:29:18.6 |
HIP 24546 |
22.07 |
| 2026-03-30 00:00 |
05:15:54.26 |
+27:29:29.6 |
HIP 24546 |
21.82 |
| 2026-03-30 12:00 |
05:16:11.40 |
+27:29:40.6 |
HIP 24579 |
21.66 |
| 2026-03-31 00:00 |
05:16:28.68 |
+27:29:51.8 |
HIP 24647 |
19.76 |
| 2026-03-31 12:00 |
05:16:46.12 |
+27:30:03.1 |
HIP 24647 |
17.62 |
| 2026-04-01 00:00 |
05:17:03.71 |
+27:30:14.4 |
HIP 24647 |
16.13 |
| 2026-04-01 12:00 |
05:17:21.44 |
+27:30:25.9 |
HIP 24647 |
15.49 |
| 2026-04-02 00:00 |
05:17:39.32 |
+27:30:37.5 |
HIP 24647 |
15.85 |
| 2026-04-02 12:00 |
05:17:57.34 |
+27:30:49.2 |
HIP 24647 |
17.15 |
| 2026-04-03 00:00 |
05:18:15.51 |
+27:31:00.9 |
HIP 24647 |
19.23 |
| 2026-04-03 12:00 |
05:18:33.82 |
+27:31:12.8 |
HIP 24647 |
21.88 |
| 2026-04-04 00:00 |
05:18:52.27 |
+27:31:24.7 |
HIP 24896 |
18.84 |
| 2026-04-04 12:00 |
05:19:10.86 |
+27:31:36.7 |
HIP 24896 |
15.04 |
| 2026-04-05 00:00 |
05:19:29.59 |
+27:31:48.8 |
HIP 24896 |
11.43 |
| 2026-04-05 12:00 |
05:19:48.46 |
+27:32:00.9 |
HIP 24896 |
8.34 |
| 2026-04-06 00:00 |
05:20:07.47 |
+27:32:13.2 |
HIP 24896 |
6.59 |
| 2026-04-06 12:00 |
05:20:26.62 |
+27:32:25.5 |
HIP 24896 |
7.28 |
| 2026-04-07 00:00 |
05:20:45.90 |
+27:32:37.8 |
HIP 24896 |
9.96 |
| 2026-04-07 12:00 |
05:21:05.32 |
+27:32:50.2 |
HIP 24896 |
13.51 |
| 2026-04-08 00:00 |
05:21:24.87 |
+27:33:02.7 |
HIP 24896 |
17.44 |
| 2026-04-08 12:00 |
05:21:44.55 |
+27:33:15.2 |
HIP 24896 |
21.55 |
| 2026-04-09 00:00 |
05:22:04.37 |
+27:33:27.8 |
HIP 24896 |
25.77 |
| 2026-04-09 12:00 |
05:22:24.32 |
+27:33:40.4 |
HIP 24896 |
30.08 |
| 2026-04-10 00:00 |
05:22:44.40 |
+27:33:53.1 |
HIP 25159 |
31.16 |
| 2026-04-10 12:00 |
05:23:04.61 |
+27:34:05.8 |
HIP 25159 |
31.17 |
| 2026-04-11 00:00 |
05:23:24.94 |
+27:34:18.5 |
HIP 25159 |
31.82 |
| 2026-04-11 12:00 |
05:23:45.41 |
+27:34:31.3 |
HIP 25159 |
33.10 |
| 2026-04-12 00:00 |
05:24:06.00 |
+27:34:44.1 |
HIP 25159 |
34.94 |
| 2026-04-12 12:00 |
05:24:26.71 |
+27:34:56.9 |
HIP 25484 |
34.29 |
| 2026-04-13 00:00 |
05:24:47.55 |
+27:35:09.8 |
HIP 25484 |
29.67 |
| 2026-04-13 12:00 |
05:25:08.52 |
+27:35:22.6 |
HIP 25484 |
25.02 |
| 2026-04-14 00:00 |
05:25:29.61 |
+27:35:35.5 |
HIP 25484 |
20.34 |
| 2026-04-14 12:00 |
05:25:50.82 |
+27:35:48.4 |
HIP 25484 |
15.64 |
| 2026-04-15 00:00 |
05:26:12.15 |
+27:36:01.3 |
HIP 25484 |
10.91 |
| 2026-04-15 12:00 |
05:26:33.60 |
+27:36:14.2 |
HIP 25484 |
6.15 |
| 2026-04-16 00:00 |
05:26:55.17 |
+27:36:27.2 |
HIP 25484 |
1.37 |