メタデータ
| 項目 |
値 |
| Designation |
C/1978 A1 (West) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1977-07-21T10:46:21.555840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:26Z |
| Obs used |
60 |
| NEO |
- |
| M1 |
6.000 |
| K1 |
8.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1978-03-26.0000000 |
| e |
1.00269511 |
| q (au) |
5.606239 |
| a (au) |
-2080.153011 |
| i (deg) |
116.921045 |
| Ω (om, deg) |
211.624226 |
| ω (w, deg) |
343.273891 |
| M (ma, deg) |
0.002572 |
等級
散乱 + 全体線形
$$
M_a = (-0.758 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
-0.758 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.506 |
| 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 |
02:36:32.47 |
+60:31:12.1 |
HIP 12009 |
12.98 |
| 2026-03-26 12:00 |
02:36:35.04 |
+60:31:04.4 |
HIP 12009 |
13.31 |
| 2026-03-27 00:00 |
02:36:37.61 |
+60:30:57.0 |
HIP 12009 |
13.65 |
| 2026-03-27 12:00 |
02:36:40.21 |
+60:30:49.6 |
HIP 12009 |
13.98 |
| 2026-03-28 00:00 |
02:36:42.82 |
+60:30:42.5 |
HIP 12009 |
14.32 |
| 2026-03-28 12:00 |
02:36:45.44 |
+60:30:35.4 |
HIP 12009 |
14.66 |
| 2026-03-29 00:00 |
02:36:48.08 |
+60:30:28.6 |
HIP 12009 |
15.00 |
| 2026-03-29 12:00 |
02:36:50.74 |
+60:30:21.8 |
HIP 12009 |
15.34 |
| 2026-03-30 00:00 |
02:36:53.40 |
+60:30:15.3 |
HIP 12009 |
15.68 |
| 2026-03-30 12:00 |
02:36:56.09 |
+60:30:08.9 |
HIP 12009 |
16.03 |
| 2026-03-31 00:00 |
02:36:58.78 |
+60:30:02.6 |
HIP 12009 |
16.37 |
| 2026-03-31 12:00 |
02:37:01.49 |
+60:29:56.5 |
HIP 12009 |
16.72 |
| 2026-04-01 00:00 |
02:37:04.22 |
+60:29:50.5 |
HIP 12009 |
17.07 |
| 2026-04-01 12:00 |
02:37:06.96 |
+60:29:44.7 |
HIP 12009 |
17.42 |
| 2026-04-02 00:00 |
02:37:09.71 |
+60:29:39.1 |
HIP 12009 |
17.77 |
| 2026-04-02 12:00 |
02:37:12.47 |
+60:29:33.6 |
HIP 12009 |
18.12 |
| 2026-04-03 00:00 |
02:37:15.25 |
+60:29:28.3 |
HIP 12009 |
18.47 |
| 2026-04-03 12:00 |
02:37:18.04 |
+60:29:23.1 |
HIP 12009 |
18.83 |
| 2026-04-04 00:00 |
02:37:20.84 |
+60:29:18.0 |
HIP 12009 |
19.18 |
| 2026-04-04 12:00 |
02:37:23.65 |
+60:29:13.2 |
HIP 12009 |
19.54 |
| 2026-04-05 00:00 |
02:37:26.48 |
+60:29:08.4 |
HIP 12009 |
19.89 |
| 2026-04-05 12:00 |
02:37:29.32 |
+60:29:03.9 |
HIP 12009 |
20.25 |
| 2026-04-06 00:00 |
02:37:32.17 |
+60:28:59.5 |
HIP 12009 |
20.61 |
| 2026-04-06 12:00 |
02:37:35.03 |
+60:28:55.2 |
HIP 12009 |
20.97 |
| 2026-04-07 00:00 |
02:37:37.90 |
+60:28:51.1 |
HIP 12009 |
21.33 |
| 2026-04-07 12:00 |
02:37:40.79 |
+60:28:47.1 |
HIP 12009 |
21.69 |
| 2026-04-08 00:00 |
02:37:43.68 |
+60:28:43.3 |
HIP 12009 |
22.05 |
| 2026-04-08 12:00 |
02:37:46.59 |
+60:28:39.7 |
HIP 12009 |
22.42 |
| 2026-04-09 00:00 |
02:37:49.50 |
+60:28:36.2 |
HIP 12009 |
22.78 |
| 2026-04-09 12:00 |
02:37:52.43 |
+60:28:32.9 |
HIP 12009 |
23.15 |
| 2026-04-10 00:00 |
02:37:55.37 |
+60:28:29.7 |
HIP 12228 |
23.47 |
| 2026-04-10 12:00 |
02:37:58.32 |
+60:28:26.7 |
HIP 12228 |
23.48 |
| 2026-04-11 00:00 |
02:38:01.27 |
+60:28:23.8 |
HIP 12228 |
23.50 |
| 2026-04-11 12:00 |
02:38:04.24 |
+60:28:21.1 |
HIP 12228 |
23.52 |
| 2026-04-12 00:00 |
02:38:07.22 |
+60:28:18.6 |
HIP 12228 |
23.56 |
| 2026-04-12 12:00 |
02:38:10.20 |
+60:28:16.2 |
HIP 12228 |
23.60 |
| 2026-04-13 00:00 |
02:38:13.19 |
+60:28:13.9 |
HIP 12228 |
23.66 |
| 2026-04-13 12:00 |
02:38:16.20 |
+60:28:11.8 |
HIP 12543 |
23.66 |
| 2026-04-14 00:00 |
02:38:19.21 |
+60:28:09.9 |
HIP 12543 |
23.30 |
| 2026-04-14 12:00 |
02:38:22.23 |
+60:28:08.1 |
HIP 12543 |
22.95 |
| 2026-04-15 00:00 |
02:38:25.26 |
+60:28:06.5 |
HIP 12543 |
22.59 |
| 2026-04-15 12:00 |
02:38:28.29 |
+60:28:05.1 |
HIP 12543 |
22.23 |
| 2026-04-16 00:00 |
02:38:31.33 |
+60:28:03.8 |
HIP 12543 |
21.87 |