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) |
| 2026-09-20 00:00 |
07:46:30.87 |
+26:59:04.8 |
HIP 37886 |
17.69 |
| 2026-09-20 12:00 |
07:46:50.49 |
+26:58:57.2 |
HIP 37886 |
20.05 |
| 2026-09-21 00:00 |
07:47:09.99 |
+26:58:49.9 |
HIP 37886 |
22.99 |
| 2026-09-21 12:00 |
07:47:29.35 |
+26:58:43.0 |
HIP 37886 |
26.30 |
| 2026-09-22 00:00 |
07:47:48.58 |
+26:58:36.4 |
HIP 37886 |
29.86 |
| 2026-09-22 12:00 |
07:48:07.69 |
+26:58:30.3 |
HIP 38228 |
33.36 |
| 2026-09-23 00:00 |
07:48:26.66 |
+26:58:24.5 |
HIP 38228 |
30.55 |
| 2026-09-23 12:00 |
07:48:45.50 |
+26:58:19.2 |
HIP 38228 |
28.11 |
| 2026-09-24 00:00 |
07:49:04.21 |
+26:58:14.2 |
HIP 38228 |
26.13 |
| 2026-09-24 12:00 |
07:49:22.79 |
+26:58:09.6 |
HIP 38228 |
24.70 |
| 2026-09-25 00:00 |
07:49:41.23 |
+26:58:05.4 |
HIP 38228 |
23.90 |
| 2026-09-25 12:00 |
07:49:59.53 |
+26:58:01.7 |
HIP 38228 |
23.79 |
| 2026-09-26 00:00 |
07:50:17.70 |
+26:57:58.4 |
HIP 38228 |
24.35 |
| 2026-09-26 12:00 |
07:50:35.73 |
+26:57:55.4 |
HIP 38228 |
25.52 |
| 2026-09-27 00:00 |
07:50:53.62 |
+26:57:52.9 |
HIP 38228 |
27.23 |
| 2026-09-27 12:00 |
07:51:11.38 |
+26:57:50.9 |
HIP 38228 |
29.35 |
| 2026-09-28 00:00 |
07:51:28.99 |
+26:57:49.3 |
HIP 38538 |
29.45 |
| 2026-09-28 12:00 |
07:51:46.46 |
+26:57:48.1 |
HIP 38538 |
25.92 |
| 2026-09-29 00:00 |
07:52:03.79 |
+26:57:47.4 |
HIP 38538 |
22.55 |
| 2026-09-29 12:00 |
07:52:20.98 |
+26:57:47.1 |
HIP 38538 |
19.39 |
| 2026-09-30 00:00 |
07:52:38.02 |
+26:57:47.3 |
HIP 38538 |
16.54 |
| 2026-09-30 12:00 |
07:52:54.92 |
+26:57:47.9 |
HIP 38538 |
14.18 |
| 2026-10-01 00:00 |
07:53:11.67 |
+26:57:49.0 |
HIP 38538 |
12.54 |
| 2026-10-01 12:00 |
07:53:28.27 |
+26:57:50.6 |
HIP 38538 |
11.90 |
| 2026-10-02 00:00 |
07:53:44.73 |
+26:57:52.6 |
HIP 38538 |
12.38 |
| 2026-10-02 12:00 |
07:54:01.04 |
+26:57:55.2 |
HIP 38538 |
13.84 |
| 2026-10-03 00:00 |
07:54:17.19 |
+26:57:58.2 |
HIP 38679 |
13.33 |
| 2026-10-03 12:00 |
07:54:33.20 |
+26:58:01.7 |
HIP 38679 |
10.39 |
| 2026-10-04 00:00 |
07:54:49.05 |
+26:58:05.8 |
HIP 38679 |
7.98 |
| 2026-10-04 12:00 |
07:55:04.74 |
+26:58:10.3 |
HIP 38679 |
6.67 |
| 2026-10-05 00:00 |
07:55:20.28 |
+26:58:15.3 |
HIP 38679 |
7.03 |
| 2026-10-05 12:00 |
07:55:35.67 |
+26:58:20.9 |
HIP 38679 |
8.82 |
| 2026-10-06 00:00 |
07:55:50.90 |
+26:58:27.0 |
HIP 38679 |
11.35 |
| 2026-10-06 12:00 |
07:56:05.97 |
+26:58:33.6 |
HIP 38679 |
14.21 |
| 2026-10-07 00:00 |
07:56:20.87 |
+26:58:40.7 |
HIP 38679 |
17.21 |
| 2026-10-07 12:00 |
07:56:35.62 |
+26:58:48.4 |
HIP 38679 |
20.28 |
| 2026-10-08 00:00 |
07:56:50.21 |
+26:58:56.6 |
HIP 38679 |
23.37 |
| 2026-10-08 12:00 |
07:57:04.63 |
+26:59:05.4 |
HIP 38679 |
26.45 |
| 2026-10-09 00:00 |
07:57:18.89 |
+26:59:14.7 |
HIP 38679 |
29.53 |
| 2026-10-09 12:00 |
07:57:32.98 |
+26:59:24.6 |
HIP 38903 |
29.95 |
| 2026-10-10 00:00 |
07:57:46.90 |
+26:59:35.1 |
HIP 38903 |
29.74 |
| 2026-10-10 12:00 |
07:58:00.66 |
+26:59:46.1 |
HIP 38903 |
29.83 |
| 2026-10-11 00:00 |
07:58:14.25 |
+26:59:57.7 |
HIP 38903 |
30.22 |