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) |
| 2026-07-29 00:00 |
07:27:14.69 |
-60:18:30.6 |
HIP 36428 |
22.50 |
| 2026-07-29 12:00 |
07:27:18.07 |
-60:18:38.6 |
HIP 36428 |
22.21 |
| 2026-07-30 00:00 |
07:27:21.43 |
-60:18:46.8 |
HIP 36428 |
21.94 |
| 2026-07-30 12:00 |
07:27:24.79 |
-60:18:55.2 |
HIP 36428 |
21.67 |
| 2026-07-31 00:00 |
07:27:28.15 |
-60:19:03.8 |
HIP 36428 |
21.41 |
| 2026-07-31 12:00 |
07:27:31.49 |
-60:19:12.7 |
HIP 36428 |
21.17 |
| 2026-08-01 00:00 |
07:27:34.82 |
-60:19:21.7 |
HIP 36428 |
20.93 |
| 2026-08-01 12:00 |
07:27:38.15 |
-60:19:30.9 |
HIP 36428 |
20.70 |
| 2026-08-02 00:00 |
07:27:41.46 |
-60:19:40.4 |
HIP 36428 |
20.48 |
| 2026-08-02 12:00 |
07:27:44.77 |
-60:19:50.0 |
HIP 36428 |
20.27 |
| 2026-08-03 00:00 |
07:27:48.06 |
-60:19:59.9 |
HIP 36428 |
20.07 |
| 2026-08-03 12:00 |
07:27:51.35 |
-60:20:09.9 |
HIP 36428 |
19.88 |
| 2026-08-04 00:00 |
07:27:54.63 |
-60:20:20.2 |
HIP 36428 |
19.71 |
| 2026-08-04 12:00 |
07:27:57.89 |
-60:20:30.7 |
HIP 36428 |
19.54 |
| 2026-08-05 00:00 |
07:28:01.15 |
-60:20:41.4 |
HIP 36428 |
19.39 |
| 2026-08-05 12:00 |
07:28:04.39 |
-60:20:52.2 |
HIP 36428 |
19.25 |
| 2026-08-06 00:00 |
07:28:07.62 |
-60:21:03.3 |
HIP 36428 |
19.12 |
| 2026-08-06 12:00 |
07:28:10.85 |
-60:21:14.6 |
HIP 36428 |
19.01 |
| 2026-08-07 00:00 |
07:28:14.06 |
-60:21:26.1 |
HIP 36428 |
18.91 |
| 2026-08-07 12:00 |
07:28:17.25 |
-60:21:37.8 |
HIP 36428 |
18.82 |
| 2026-08-08 00:00 |
07:28:20.44 |
-60:21:49.7 |
HIP 36428 |
18.75 |
| 2026-08-08 12:00 |
07:28:23.61 |
-60:22:01.8 |
HIP 36428 |
18.69 |
| 2026-08-09 00:00 |
07:28:26.78 |
-60:22:14.0 |
HIP 36428 |
18.64 |
| 2026-08-09 12:00 |
07:28:29.93 |
-60:22:26.5 |
HIP 36428 |
18.61 |
| 2026-08-10 00:00 |
07:28:33.06 |
-60:22:39.2 |
HIP 36428 |
18.59 |
| 2026-08-10 12:00 |
07:28:36.19 |
-60:22:52.1 |
HIP 36428 |
18.59 |
| 2026-08-11 00:00 |
07:28:39.29 |
-60:23:05.2 |
HIP 36428 |
18.60 |
| 2026-08-11 12:00 |
07:28:42.39 |
-60:23:18.4 |
HIP 36428 |
18.62 |
| 2026-08-12 00:00 |
07:28:45.47 |
-60:23:31.9 |
HIP 36428 |
18.66 |
| 2026-08-12 12:00 |
07:28:48.54 |
-60:23:45.6 |
HIP 36428 |
18.71 |
| 2026-08-13 00:00 |
07:28:51.59 |
-60:23:59.4 |
HIP 36428 |
18.78 |
| 2026-08-13 12:00 |
07:28:54.63 |
-60:24:13.5 |
HIP 36428 |
18.86 |
| 2026-08-14 00:00 |
07:28:57.66 |
-60:24:27.7 |
HIP 36428 |
18.96 |
| 2026-08-14 12:00 |
07:29:00.67 |
-60:24:42.1 |
HIP 36428 |
19.07 |
| 2026-08-15 00:00 |
07:29:03.66 |
-60:24:56.8 |
HIP 36428 |
19.19 |
| 2026-08-15 12:00 |
07:29:06.64 |
-60:25:11.6 |
HIP 36428 |
19.32 |
| 2026-08-16 00:00 |
07:29:09.60 |
-60:25:26.6 |
HIP 36428 |
19.47 |
| 2026-08-16 12:00 |
07:29:12.55 |
-60:25:41.7 |
HIP 36428 |
19.63 |
| 2026-08-17 00:00 |
07:29:15.48 |
-60:25:57.1 |
HIP 36428 |
19.80 |
| 2026-08-17 12:00 |
07:29:18.39 |
-60:26:12.6 |
HIP 36428 |
19.98 |
| 2026-08-18 00:00 |
07:29:21.29 |
-60:26:28.4 |
HIP 36428 |
20.18 |
| 2026-08-18 12:00 |
07:29:24.17 |
-60:26:44.3 |
HIP 36428 |
20.39 |
| 2026-08-19 00:00 |
07:29:27.03 |
-60:27:00.4 |
HIP 36428 |
20.60 |