メタデータ
| 項目 |
値 |
| Designation |
C/1973 D1 (Kohoutek) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1973-06-07T04:20:15.918720Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:22Z |
| Obs used |
42 |
| NEO |
- |
| M1 |
9.700 |
| K1 |
18.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1973-04-20.0000000 |
| e |
0.99874973 |
| q (au) |
1.382021 |
| a (au) |
1105.378577 |
| i (deg) |
121.598063 |
| Ω (om, deg) |
164.817374 |
| ω (w, deg) |
74.859255 |
| M (ma, deg) |
359.998708 |
等級
散乱 + 全体線形
$$
M_a = (8.986 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.986 |
| 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 |
21:52:14.42 |
-64:37:51.6 |
HIP 107773 |
15.17 |
| 2026-07-29 12:00 |
21:52:11.22 |
-64:38:02.7 |
HIP 107773 |
14.79 |
| 2026-07-30 00:00 |
21:52:08.01 |
-64:38:13.5 |
HIP 107773 |
14.40 |
| 2026-07-30 12:00 |
21:52:04.80 |
-64:38:24.3 |
HIP 107773 |
14.02 |
| 2026-07-31 00:00 |
21:52:01.57 |
-64:38:34.9 |
HIP 107773 |
13.64 |
| 2026-07-31 12:00 |
21:51:58.34 |
-64:38:45.3 |
HIP 107773 |
13.25 |
| 2026-08-01 00:00 |
21:51:55.09 |
-64:38:55.7 |
HIP 107773 |
12.87 |
| 2026-08-01 12:00 |
21:51:51.84 |
-64:39:05.9 |
HIP 107773 |
12.49 |
| 2026-08-02 00:00 |
21:51:48.58 |
-64:39:15.9 |
HIP 107773 |
12.10 |
| 2026-08-02 12:00 |
21:51:45.30 |
-64:39:25.8 |
HIP 107773 |
11.72 |
| 2026-08-03 00:00 |
21:51:42.02 |
-64:39:35.6 |
HIP 107773 |
11.34 |
| 2026-08-03 12:00 |
21:51:38.74 |
-64:39:45.2 |
HIP 107773 |
10.96 |
| 2026-08-04 00:00 |
21:51:35.44 |
-64:39:54.7 |
HIP 107773 |
10.57 |
| 2026-08-04 12:00 |
21:51:32.14 |
-64:40:04.1 |
HIP 107773 |
10.19 |
| 2026-08-05 00:00 |
21:51:28.83 |
-64:40:13.3 |
HIP 107773 |
9.81 |
| 2026-08-05 12:00 |
21:51:25.51 |
-64:40:22.3 |
HIP 107773 |
9.43 |
| 2026-08-06 00:00 |
21:51:22.19 |
-64:40:31.3 |
HIP 107773 |
9.05 |
| 2026-08-06 12:00 |
21:51:18.85 |
-64:40:40.0 |
HIP 107773 |
8.67 |
| 2026-08-07 00:00 |
21:51:15.52 |
-64:40:48.7 |
HIP 107773 |
8.28 |
| 2026-08-07 12:00 |
21:51:12.17 |
-64:40:57.1 |
HIP 107773 |
7.90 |
| 2026-08-08 00:00 |
21:51:08.82 |
-64:41:05.5 |
HIP 107773 |
7.52 |
| 2026-08-08 12:00 |
21:51:05.47 |
-64:41:13.7 |
HIP 107773 |
7.14 |
| 2026-08-09 00:00 |
21:51:02.11 |
-64:41:21.7 |
HIP 107773 |
6.76 |
| 2026-08-09 12:00 |
21:50:58.74 |
-64:41:29.6 |
HIP 107773 |
6.39 |
| 2026-08-10 00:00 |
21:50:55.37 |
-64:41:37.3 |
HIP 107773 |
6.01 |
| 2026-08-10 12:00 |
21:50:51.99 |
-64:41:44.9 |
HIP 107773 |
5.63 |
| 2026-08-11 00:00 |
21:50:48.61 |
-64:41:52.3 |
HIP 107773 |
5.25 |
| 2026-08-11 12:00 |
21:50:45.23 |
-64:41:59.6 |
HIP 107773 |
4.88 |
| 2026-08-12 00:00 |
21:50:41.84 |
-64:42:06.7 |
HIP 107773 |
4.50 |
| 2026-08-12 12:00 |
21:50:38.45 |
-64:42:13.7 |
HIP 107773 |
4.13 |
| 2026-08-13 00:00 |
21:50:35.06 |
-64:42:20.5 |
HIP 107773 |
3.75 |
| 2026-08-13 12:00 |
21:50:31.66 |
-64:42:27.2 |
HIP 107773 |
3.38 |
| 2026-08-14 00:00 |
21:50:28.26 |
-64:42:33.7 |
HIP 107773 |
3.01 |
| 2026-08-14 12:00 |
21:50:24.86 |
-64:42:40.1 |
HIP 107773 |
2.64 |
| 2026-08-15 00:00 |
21:50:21.45 |
-64:42:46.3 |
HIP 107773 |
2.28 |
| 2026-08-15 12:00 |
21:50:18.05 |
-64:42:52.3 |
HIP 107773 |
1.92 |
| 2026-08-16 00:00 |
21:50:14.64 |
-64:42:58.2 |
HIP 107773 |
1.57 |
| 2026-08-16 12:00 |
21:50:11.23 |
-64:43:03.9 |
HIP 107773 |
1.23 |
| 2026-08-17 00:00 |
21:50:07.82 |
-64:43:09.5 |
HIP 107773 |
0.92 |
| 2026-08-17 12:00 |
21:50:04.41 |
-64:43:14.9 |
HIP 107773 |
0.68 |
| 2026-08-18 00:00 |
21:50:01.00 |
-64:43:20.2 |
HIP 107773 |
0.60 |
| 2026-08-18 12:00 |
21:49:57.59 |
-64:43:25.2 |
HIP 107773 |
0.73 |
| 2026-08-19 00:00 |
21:49:54.18 |
-64:43:30.2 |
HIP 107773 |
0.99 |