メタデータ
| 項目 |
値 |
| Designation |
C/1987 A1 (Levy) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1986-12-17T12:41:46.420800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:33Z |
| Obs used |
62 |
| NEO |
- |
| M1 |
10.800 |
| K1 |
21.250 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1987-02-19.0000000 |
| e |
1.00039441 |
| q (au) |
0.921480 |
| a (au) |
-2336.349359 |
| i (deg) |
96.582920 |
| Ω (om, deg) |
17.116643 |
| ω (w, deg) |
95.245094 |
| M (ma, deg) |
0.000554 |
等級
散乱 + 全体線形
$$
M_a = (9.544 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
9.544 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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 |
07:31:46.63 |
-60:49:29.0 |
HIP 36861 |
26.36 |
| 2026-09-20 12:00 |
07:31:48.00 |
-60:49:54.0 |
HIP 36861 |
25.98 |
| 2026-09-21 00:00 |
07:31:49.34 |
-60:50:19.2 |
HIP 36861 |
25.60 |
| 2026-09-21 12:00 |
07:31:50.66 |
-60:50:44.4 |
HIP 36861 |
25.23 |
| 2026-09-22 00:00 |
07:31:51.94 |
-60:51:09.8 |
HIP 36861 |
24.86 |
| 2026-09-22 12:00 |
07:31:53.20 |
-60:51:35.2 |
HIP 36861 |
24.50 |
| 2026-09-23 00:00 |
07:31:54.43 |
-60:52:00.7 |
HIP 36861 |
24.14 |
| 2026-09-23 12:00 |
07:31:55.63 |
-60:52:26.2 |
HIP 36861 |
23.79 |
| 2026-09-24 00:00 |
07:31:56.81 |
-60:52:51.9 |
HIP 36861 |
23.44 |
| 2026-09-24 12:00 |
07:31:57.95 |
-60:53:17.6 |
HIP 36861 |
23.10 |
| 2026-09-25 00:00 |
07:31:59.06 |
-60:53:43.4 |
HIP 36861 |
22.77 |
| 2026-09-25 12:00 |
07:32:00.15 |
-60:54:09.2 |
HIP 36861 |
22.44 |
| 2026-09-26 00:00 |
07:32:01.20 |
-60:54:35.2 |
HIP 36861 |
22.12 |
| 2026-09-26 12:00 |
07:32:02.23 |
-60:55:01.2 |
HIP 36861 |
21.81 |
| 2026-09-27 00:00 |
07:32:03.23 |
-60:55:27.2 |
HIP 36861 |
21.51 |
| 2026-09-27 12:00 |
07:32:04.19 |
-60:55:53.4 |
HIP 36861 |
21.21 |
| 2026-09-28 00:00 |
07:32:05.13 |
-60:56:19.6 |
HIP 36861 |
20.92 |
| 2026-09-28 12:00 |
07:32:06.04 |
-60:56:45.8 |
HIP 36861 |
20.64 |
| 2026-09-29 00:00 |
07:32:06.91 |
-60:57:12.1 |
HIP 36861 |
20.37 |
| 2026-09-29 12:00 |
07:32:07.76 |
-60:57:38.5 |
HIP 36861 |
20.11 |
| 2026-09-30 00:00 |
07:32:08.58 |
-60:58:04.9 |
HIP 36861 |
19.86 |
| 2026-09-30 12:00 |
07:32:09.37 |
-60:58:31.4 |
HIP 36861 |
19.62 |
| 2026-10-01 00:00 |
07:32:10.12 |
-60:58:58.0 |
HIP 36861 |
19.39 |
| 2026-10-01 12:00 |
07:32:10.85 |
-60:59:24.6 |
HIP 36861 |
19.17 |
| 2026-10-02 00:00 |
07:32:11.54 |
-60:59:51.2 |
HIP 36861 |
18.96 |
| 2026-10-02 12:00 |
07:32:12.21 |
-61:00:17.9 |
HIP 36861 |
18.76 |
| 2026-10-03 00:00 |
07:32:12.84 |
-61:00:44.6 |
HIP 36861 |
18.58 |
| 2026-10-03 12:00 |
07:32:13.45 |
-61:01:11.4 |
HIP 36861 |
18.41 |
| 2026-10-04 00:00 |
07:32:14.02 |
-61:01:38.2 |
HIP 36861 |
18.25 |
| 2026-10-04 12:00 |
07:32:14.56 |
-61:02:05.1 |
HIP 36861 |
18.11 |
| 2026-10-05 00:00 |
07:32:15.07 |
-61:02:32.0 |
HIP 36861 |
17.98 |
| 2026-10-05 12:00 |
07:32:15.55 |
-61:02:58.9 |
HIP 36861 |
17.87 |
| 2026-10-06 00:00 |
07:32:16.00 |
-61:03:25.9 |
HIP 36861 |
17.77 |
| 2026-10-06 12:00 |
07:32:16.41 |
-61:03:52.9 |
HIP 36861 |
17.68 |
| 2026-10-07 00:00 |
07:32:16.80 |
-61:04:19.9 |
HIP 36861 |
17.61 |
| 2026-10-07 12:00 |
07:32:17.15 |
-61:04:47.0 |
HIP 36861 |
17.56 |
| 2026-10-08 00:00 |
07:32:17.47 |
-61:05:14.1 |
HIP 36861 |
17.52 |
| 2026-10-08 12:00 |
07:32:17.76 |
-61:05:41.2 |
HIP 36861 |
17.49 |
| 2026-10-09 00:00 |
07:32:18.02 |
-61:06:08.3 |
HIP 36861 |
17.48 |
| 2026-10-09 12:00 |
07:32:18.24 |
-61:06:35.5 |
HIP 36861 |
17.49 |
| 2026-10-10 00:00 |
07:32:18.44 |
-61:07:02.6 |
HIP 36861 |
17.51 |
| 2026-10-10 12:00 |
07:32:18.60 |
-61:07:29.8 |
HIP 36861 |
17.55 |
| 2026-10-11 00:00 |
07:32:18.73 |
-61:07:57.0 |
HIP 36861 |
17.60 |