メタデータ
| 項目 |
値 |
| Designation |
C/1991 L4 (Helin-Alu) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1992-02-19T22:39:07.948800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:41Z |
| Obs used |
80 |
| NEO |
- |
| M1 |
10.100 |
| 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) |
1992-06-10.0000000 |
| e |
1.00017877 |
| q (au) |
4.849875 |
| a (au) |
-27129.680481 |
| i (deg) |
49.292514 |
| Ω (om, deg) |
253.650707 |
| ω (w, deg) |
30.794475 |
| M (ma, deg) |
0.000024 |
等級
散乱 + 全体線形
$$
M_a = (0.872 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
0.872 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.501 |
| 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) |
| 2026-03-26 00:00 |
04:32:24.47 |
+24:50:51.0 |
HIP 21103 |
18.92 |
| 2026-03-26 12:00 |
04:32:25.55 |
+24:50:50.3 |
HIP 21103 |
19.13 |
| 2026-03-27 00:00 |
04:32:26.65 |
+24:50:49.7 |
HIP 21103 |
19.34 |
| 2026-03-27 12:00 |
04:32:27.77 |
+24:50:49.1 |
HIP 21103 |
19.55 |
| 2026-03-28 00:00 |
04:32:28.91 |
+24:50:48.5 |
HIP 21103 |
19.77 |
| 2026-03-28 12:00 |
04:32:30.06 |
+24:50:48.0 |
HIP 21103 |
20.00 |
| 2026-03-29 00:00 |
04:32:31.23 |
+24:50:47.5 |
HIP 21103 |
20.22 |
| 2026-03-29 12:00 |
04:32:32.42 |
+24:50:47.1 |
HIP 21103 |
20.45 |
| 2026-03-30 00:00 |
04:32:33.63 |
+24:50:46.7 |
HIP 21174 |
20.53 |
| 2026-03-30 12:00 |
04:32:34.85 |
+24:50:46.3 |
HIP 21174 |
20.58 |
| 2026-03-31 00:00 |
04:32:36.09 |
+24:50:46.0 |
HIP 21174 |
20.62 |
| 2026-03-31 12:00 |
04:32:37.35 |
+24:50:45.7 |
HIP 21174 |
20.67 |
| 2026-04-01 00:00 |
04:32:38.62 |
+24:50:45.5 |
HIP 21174 |
20.73 |
| 2026-04-01 12:00 |
04:32:39.91 |
+24:50:45.3 |
HIP 21174 |
20.79 |
| 2026-04-02 00:00 |
04:32:41.22 |
+24:50:45.2 |
HIP 21174 |
20.85 |
| 2026-04-02 12:00 |
04:32:42.54 |
+24:50:45.1 |
HIP 21174 |
20.92 |
| 2026-04-03 00:00 |
04:32:43.88 |
+24:50:45.0 |
HIP 21174 |
20.99 |
| 2026-04-03 12:00 |
04:32:45.24 |
+24:50:45.0 |
HIP 21174 |
21.06 |
| 2026-04-04 00:00 |
04:32:46.61 |
+24:50:45.0 |
HIP 21174 |
21.14 |
| 2026-04-04 12:00 |
04:32:48.00 |
+24:50:45.1 |
HIP 21174 |
21.23 |
| 2026-04-05 00:00 |
04:32:49.40 |
+24:50:45.2 |
HIP 21174 |
21.32 |
| 2026-04-05 12:00 |
04:32:50.82 |
+24:50:45.3 |
HIP 21174 |
21.41 |
| 2026-04-06 00:00 |
04:32:52.26 |
+24:50:45.5 |
HIP 21174 |
21.51 |
| 2026-04-06 12:00 |
04:32:53.71 |
+24:50:45.7 |
HIP 21174 |
21.62 |
| 2026-04-07 00:00 |
04:32:55.18 |
+24:50:46.0 |
HIP 21174 |
21.73 |
| 2026-04-07 12:00 |
04:32:56.66 |
+24:50:46.3 |
HIP 21174 |
21.84 |
| 2026-04-08 00:00 |
04:32:58.16 |
+24:50:46.6 |
HIP 21174 |
21.96 |
| 2026-04-08 12:00 |
04:32:59.67 |
+24:50:47.0 |
HIP 21174 |
22.09 |
| 2026-04-09 00:00 |
04:33:01.20 |
+24:50:47.4 |
HIP 21174 |
22.22 |
| 2026-04-09 12:00 |
04:33:02.75 |
+24:50:47.9 |
HIP 21174 |
22.35 |
| 2026-04-10 00:00 |
04:33:04.30 |
+24:50:48.4 |
HIP 21174 |
22.49 |
| 2026-04-10 12:00 |
04:33:05.88 |
+24:50:48.9 |
HIP 21174 |
22.64 |
| 2026-04-11 00:00 |
04:33:07.47 |
+24:50:49.5 |
HIP 21174 |
22.79 |
| 2026-04-11 12:00 |
04:33:09.07 |
+24:50:50.1 |
HIP 21275 |
22.87 |
| 2026-04-12 00:00 |
04:33:10.69 |
+24:50:50.7 |
HIP 21275 |
22.73 |
| 2026-04-12 12:00 |
04:33:12.32 |
+24:50:51.4 |
HIP 21275 |
22.59 |
| 2026-04-13 00:00 |
04:33:13.97 |
+24:50:52.2 |
HIP 21275 |
22.45 |
| 2026-04-13 12:00 |
04:33:15.63 |
+24:50:52.9 |
HIP 21275 |
22.32 |
| 2026-04-14 00:00 |
04:33:17.30 |
+24:50:53.7 |
HIP 21275 |
22.20 |
| 2026-04-14 12:00 |
04:33:18.99 |
+24:50:54.6 |
HIP 21275 |
22.08 |
| 2026-04-15 00:00 |
04:33:20.70 |
+24:50:55.4 |
HIP 21275 |
21.96 |
| 2026-04-15 12:00 |
04:33:22.41 |
+24:50:56.4 |
HIP 21275 |
21.86 |
| 2026-04-16 00:00 |
04:33:24.14 |
+24:50:57.3 |
HIP 21275 |
21.75 |