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 |
-0.923 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
07:02:46.19 |
+27:30:40.2 |
HIP 33915 |
15.74 |
| 2026-07-29 12:00 |
07:03:14.48 |
+27:30:20.5 |
HIP 33915 |
19.38 |
| 2026-07-30 00:00 |
07:03:42.74 |
+27:30:00.6 |
HIP 33915 |
24.12 |
| 2026-07-30 12:00 |
07:04:10.95 |
+27:29:40.6 |
HIP 34222 |
20.30 |
| 2026-07-31 00:00 |
07:04:39.12 |
+27:29:20.6 |
HIP 34222 |
14.05 |
| 2026-07-31 12:00 |
07:05:07.25 |
+27:29:00.4 |
HIP 34222 |
7.80 |
| 2026-08-01 00:00 |
07:05:35.33 |
+27:28:40.2 |
HIP 34222 |
1.59 |
| 2026-08-01 12:00 |
07:06:03.37 |
+27:28:19.9 |
HIP 34222 |
4.68 |
| 2026-08-02 00:00 |
07:06:31.37 |
+27:27:59.5 |
HIP 34222 |
10.89 |
| 2026-08-02 12:00 |
07:06:59.31 |
+27:27:39.1 |
HIP 34222 |
17.10 |
| 2026-08-03 00:00 |
07:07:27.22 |
+27:27:18.6 |
HIP 34222 |
23.30 |
| 2026-08-03 12:00 |
07:07:55.07 |
+27:26:58.0 |
HIP 34522 |
19.71 |
| 2026-08-04 00:00 |
07:08:22.88 |
+27:26:37.4 |
HIP 34522 |
14.94 |
| 2026-08-04 12:00 |
07:08:50.63 |
+27:26:16.7 |
HIP 34522 |
11.59 |
| 2026-08-05 00:00 |
07:09:18.34 |
+27:25:55.9 |
HIP 34522 |
11.02 |
| 2026-08-05 12:00 |
07:09:46.00 |
+27:25:35.1 |
HIP 34522 |
13.57 |
| 2026-08-06 00:00 |
07:10:13.61 |
+27:25:14.3 |
HIP 34522 |
17.94 |
| 2026-08-06 12:00 |
07:10:41.17 |
+27:24:53.4 |
HIP 34799 |
20.49 |
| 2026-08-07 00:00 |
07:11:08.67 |
+27:24:32.4 |
HIP 34799 |
14.44 |
| 2026-08-07 12:00 |
07:11:36.12 |
+27:24:11.4 |
HIP 34799 |
8.49 |
| 2026-08-08 00:00 |
07:12:03.52 |
+27:23:50.4 |
HIP 34799 |
3.19 |
| 2026-08-08 12:00 |
07:12:30.87 |
+27:23:29.4 |
HIP 34799 |
4.73 |
| 2026-08-09 00:00 |
07:12:58.15 |
+27:23:08.3 |
HIP 34860 |
9.84 |
| 2026-08-09 12:00 |
07:13:25.39 |
+27:22:47.2 |
HIP 34860 |
12.30 |
| 2026-08-10 00:00 |
07:13:52.56 |
+27:22:26.1 |
HIP 34860 |
16.69 |
| 2026-08-10 12:00 |
07:14:19.68 |
+27:22:04.9 |
HIP 35130 |
20.20 |
| 2026-08-11 00:00 |
07:14:46.73 |
+27:21:43.8 |
HIP 35130 |
14.74 |
| 2026-08-11 12:00 |
07:15:13.73 |
+27:21:22.6 |
HIP 35130 |
9.96 |
| 2026-08-12 00:00 |
07:15:40.67 |
+27:21:01.5 |
HIP 35130 |
7.27 |
| 2026-08-12 12:00 |
07:16:07.55 |
+27:20:40.3 |
HIP 35130 |
8.85 |
| 2026-08-13 00:00 |
07:16:34.36 |
+27:20:19.2 |
HIP 35191 |
12.18 |
| 2026-08-13 12:00 |
07:17:01.11 |
+27:19:58.0 |
HIP 35191 |
14.63 |
| 2026-08-14 00:00 |
07:17:27.80 |
+27:19:36.9 |
HIP 35377 |
14.25 |
| 2026-08-14 12:00 |
07:17:54.42 |
+27:19:15.8 |
HIP 35377 |
8.65 |
| 2026-08-15 00:00 |
07:18:20.97 |
+27:18:54.7 |
HIP 35377 |
4.10 |
| 2026-08-15 12:00 |
07:18:47.46 |
+27:18:33.6 |
HIP 35377 |
5.35 |
| 2026-08-16 00:00 |
07:19:13.89 |
+27:18:12.5 |
HIP 35377 |
10.47 |
| 2026-08-16 12:00 |
07:19:40.24 |
+27:17:51.5 |
HIP 35377 |
16.10 |
| 2026-08-17 00:00 |
07:20:06.53 |
+27:17:30.5 |
HIP 35377 |
21.85 |
| 2026-08-17 12:00 |
07:20:32.74 |
+27:17:09.6 |
HIP 35659 |
17.98 |
| 2026-08-18 00:00 |
07:20:58.89 |
+27:16:48.7 |
HIP 35659 |
14.29 |
| 2026-08-18 12:00 |
07:21:24.96 |
+27:16:27.9 |
HIP 35659 |
12.36 |
| 2026-08-19 00:00 |
07:21:50.96 |
+27:16:07.1 |
HIP 35659 |
12.99 |