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 |
-0.502 |
| 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) |
| 2026-05-12 00:00 |
07:19:15.32 |
-60:40:40.4 |
HIP 35420 |
5.74 |
| 2026-05-12 12:00 |
07:19:17.21 |
-60:40:17.7 |
HIP 35420 |
5.60 |
| 2026-05-13 00:00 |
07:19:19.13 |
-60:39:55.2 |
HIP 35420 |
5.50 |
| 2026-05-13 12:00 |
07:19:21.07 |
-60:39:32.7 |
HIP 35420 |
5.44 |
| 2026-05-14 00:00 |
07:19:23.04 |
-60:39:10.4 |
HIP 35420 |
5.41 |
| 2026-05-14 12:00 |
07:19:25.03 |
-60:38:48.2 |
HIP 35420 |
5.43 |
| 2026-05-15 00:00 |
07:19:27.05 |
-60:38:26.2 |
HIP 35420 |
5.48 |
| 2026-05-15 12:00 |
07:19:29.09 |
-60:38:04.3 |
HIP 35420 |
5.58 |
| 2026-05-16 00:00 |
07:19:31.16 |
-60:37:42.5 |
HIP 35420 |
5.71 |
| 2026-05-16 12:00 |
07:19:33.25 |
-60:37:20.9 |
HIP 35420 |
5.87 |
| 2026-05-17 00:00 |
07:19:35.36 |
-60:36:59.4 |
HIP 35420 |
6.07 |
| 2026-05-17 12:00 |
07:19:37.50 |
-60:36:38.1 |
HIP 35420 |
6.29 |
| 2026-05-18 00:00 |
07:19:39.66 |
-60:36:16.9 |
HIP 35420 |
6.54 |
| 2026-05-18 12:00 |
07:19:41.85 |
-60:35:55.9 |
HIP 35420 |
6.81 |
| 2026-05-19 00:00 |
07:19:44.06 |
-60:35:35.0 |
HIP 35420 |
7.10 |
| 2026-05-19 12:00 |
07:19:46.29 |
-60:35:14.2 |
HIP 35420 |
7.41 |
| 2026-05-20 00:00 |
07:19:48.55 |
-60:34:53.6 |
HIP 35420 |
7.74 |
| 2026-05-20 12:00 |
07:19:50.83 |
-60:34:33.2 |
HIP 35420 |
8.07 |
| 2026-05-21 00:00 |
07:19:53.13 |
-60:34:12.9 |
HIP 35420 |
8.42 |
| 2026-05-21 12:00 |
07:19:55.45 |
-60:33:52.8 |
HIP 35420 |
8.78 |
| 2026-05-22 00:00 |
07:19:57.80 |
-60:33:32.8 |
HIP 35420 |
9.15 |
| 2026-05-22 12:00 |
07:20:00.17 |
-60:33:13.0 |
HIP 35420 |
9.53 |
| 2026-05-23 00:00 |
07:20:02.56 |
-60:32:53.3 |
HIP 35420 |
9.91 |
| 2026-05-23 12:00 |
07:20:04.97 |
-60:32:33.9 |
HIP 35420 |
10.30 |
| 2026-05-24 00:00 |
07:20:07.40 |
-60:32:14.5 |
HIP 35420 |
10.69 |
| 2026-05-24 12:00 |
07:20:09.86 |
-60:31:55.3 |
HIP 35420 |
11.09 |
| 2026-05-25 00:00 |
07:20:12.33 |
-60:31:36.3 |
HIP 35420 |
11.50 |
| 2026-05-25 12:00 |
07:20:14.83 |
-60:31:17.5 |
HIP 35420 |
11.91 |
| 2026-05-26 00:00 |
07:20:17.34 |
-60:30:58.8 |
HIP 35420 |
12.32 |
| 2026-05-26 12:00 |
07:20:19.88 |
-60:30:40.3 |
HIP 35420 |
12.73 |
| 2026-05-27 00:00 |
07:20:22.44 |
-60:30:21.9 |
HIP 35420 |
13.15 |
| 2026-05-27 12:00 |
07:20:25.02 |
-60:30:03.8 |
HIP 35420 |
13.57 |
| 2026-05-28 00:00 |
07:20:27.61 |
-60:29:45.8 |
HIP 35420 |
13.99 |
| 2026-05-28 12:00 |
07:20:30.23 |
-60:29:27.9 |
HIP 35420 |
14.41 |
| 2026-05-29 00:00 |
07:20:32.86 |
-60:29:10.3 |
HIP 35420 |
14.84 |
| 2026-05-29 12:00 |
07:20:35.52 |
-60:28:52.8 |
HIP 35650 |
14.87 |
| 2026-05-30 00:00 |
07:20:38.19 |
-60:28:35.5 |
HIP 35650 |
14.48 |
| 2026-05-30 12:00 |
07:20:40.89 |
-60:28:18.3 |
HIP 35650 |
14.09 |
| 2026-05-31 00:00 |
07:20:43.60 |
-60:28:01.3 |
HIP 35650 |
13.71 |
| 2026-05-31 12:00 |
07:20:46.33 |
-60:27:44.5 |
HIP 35650 |
13.33 |
| 2026-06-01 00:00 |
07:20:49.08 |
-60:27:27.9 |
HIP 35650 |
12.95 |
| 2026-06-01 12:00 |
07:20:51.84 |
-60:27:11.5 |
HIP 35650 |
12.59 |
| 2026-06-02 00:00 |
07:20:54.63 |
-60:26:55.2 |
HIP 35650 |
12.23 |