C/1991 F2 (Helin-Lawrence)
メタデータ
| 項目 |
値 |
| Designation |
C/1991 F2 (Helin-Lawrence) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1992-01-20T00:37:43.368960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:41Z |
| Obs used |
108 |
| NEO |
- |
| M1 |
9.100 |
| K1 |
5.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1991-12-22.0000000 |
| e |
1.00042110 |
| q (au) |
1.517723 |
| a (au) |
-3604.185791 |
| i (deg) |
95.456559 |
| Ω (om, deg) |
11.835020 |
| ω (w, deg) |
271.158650 |
| M (ma, deg) |
-0.000132 |
等級
散乱 + 全体線形
$$
M_a = (9.280 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
9.280 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.848 |
| δ90 |
1.000 |
| 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) |
| 2026-02-03 00:00 |
20:33:15.45 |
+58:24:38.4 |
HIP 101184 |
22.36 |
| 2026-02-03 12:00 |
20:33:19.14 |
+58:24:44.5 |
HIP 101184 |
22.85 |
| 2026-02-04 00:00 |
20:33:22.82 |
+58:24:50.9 |
HIP 101184 |
23.34 |
| 2026-02-04 12:00 |
20:33:26.50 |
+58:24:57.5 |
HIP 101184 |
23.83 |
| 2026-02-05 00:00 |
20:33:30.17 |
+58:25:04.4 |
HIP 101184 |
24.32 |
| 2026-02-05 12:00 |
20:33:33.84 |
+58:25:11.5 |
HIP 101184 |
24.82 |
| 2026-02-06 00:00 |
20:33:37.50 |
+58:25:18.9 |
HIP 101184 |
25.31 |
| 2026-02-06 12:00 |
20:33:41.15 |
+58:25:26.6 |
HIP 101348 |
25.38 |
| 2026-02-07 00:00 |
20:33:44.80 |
+58:25:34.5 |
HIP 101348 |
25.45 |
| 2026-02-07 12:00 |
20:33:48.44 |
+58:25:42.6 |
HIP 101348 |
25.53 |
| 2026-02-08 00:00 |
20:33:52.08 |
+58:25:51.0 |
HIP 101348 |
25.61 |
| 2026-02-08 12:00 |
20:33:55.71 |
+58:25:59.6 |
HIP 101348 |
25.69 |
| 2026-02-09 00:00 |
20:33:59.33 |
+58:26:08.5 |
HIP 101348 |
25.78 |
| 2026-02-09 12:00 |
20:34:02.94 |
+58:26:17.6 |
HIP 101348 |
25.88 |
| 2026-02-10 00:00 |
20:34:06.54 |
+58:26:27.0 |
HIP 101348 |
25.98 |
| 2026-02-10 12:00 |
20:34:10.14 |
+58:26:36.6 |
HIP 101348 |
26.08 |
| 2026-02-11 00:00 |
20:34:13.73 |
+58:26:46.4 |
HIP 101348 |
26.19 |
| 2026-02-11 12:00 |
20:34:17.31 |
+58:26:56.5 |
HIP 101348 |
26.31 |
| 2026-02-12 00:00 |
20:34:20.88 |
+58:27:06.9 |
HIP 101348 |
26.43 |
| 2026-02-12 12:00 |
20:34:24.44 |
+58:27:17.5 |
HIP 101348 |
26.55 |
| 2026-02-13 00:00 |
20:34:27.99 |
+58:27:28.3 |
HIP 101348 |
26.68 |
| 2026-02-13 12:00 |
20:34:31.53 |
+58:27:39.3 |
HIP 101348 |
26.81 |
| 2026-02-14 00:00 |
20:34:35.07 |
+58:27:50.6 |
HIP 101348 |
26.95 |
| 2026-02-14 12:00 |
20:34:38.59 |
+58:28:02.2 |
HIP 101348 |
27.09 |
| 2026-02-15 00:00 |
20:34:42.10 |
+58:28:14.0 |
HIP 101348 |
27.24 |
| 2026-02-15 12:00 |
20:34:45.60 |
+58:28:26.0 |
HIP 101348 |
27.39 |
| 2026-02-16 00:00 |
20:34:49.09 |
+58:28:38.2 |
HIP 101348 |
27.55 |
| 2026-02-16 12:00 |
20:34:52.56 |
+58:28:50.7 |
HIP 101348 |
27.70 |
| 2026-02-17 00:00 |
20:34:56.03 |
+58:29:03.4 |
HIP 101348 |
27.87 |
| 2026-02-17 12:00 |
20:34:59.48 |
+58:29:16.4 |
HIP 101348 |
28.04 |
| 2026-02-18 00:00 |
20:35:02.93 |
+58:29:29.6 |
HIP 101348 |
28.21 |
| 2026-02-18 12:00 |
20:35:06.35 |
+58:29:43.0 |
HIP 101348 |
28.38 |
| 2026-02-19 00:00 |
20:35:09.77 |
+58:29:56.7 |
HIP 101348 |
28.56 |
| 2026-02-19 12:00 |
20:35:13.17 |
+58:30:10.5 |
HIP 101348 |
28.74 |
| 2026-02-20 00:00 |
20:35:16.56 |
+58:30:24.6 |
HIP 101348 |
28.93 |
| 2026-02-20 12:00 |
20:35:19.94 |
+58:30:39.0 |
HIP 101348 |
29.12 |
| 2026-02-21 00:00 |
20:35:23.30 |
+58:30:53.5 |
HIP 101348 |
29.31 |
| 2026-02-21 12:00 |
20:35:26.65 |
+58:31:08.3 |
HIP 101348 |
29.51 |
| 2026-02-22 00:00 |
20:35:29.99 |
+58:31:23.3 |
HIP 101348 |
29.71 |
| 2026-02-22 12:00 |
20:35:33.31 |
+58:31:38.5 |
HIP 101348 |
29.91 |
| 2026-02-23 00:00 |
20:35:36.61 |
+58:31:54.0 |
HIP 101348 |
30.12 |
| 2026-02-23 12:00 |
20:35:39.90 |
+58:32:09.6 |
HIP 101348 |
30.33 |
| 2026-02-24 00:00 |
20:35:43.18 |
+58:32:25.5 |
HIP 101348 |
30.54 |