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) |
| 2026-09-20 00:00 |
21:46:27.79 |
-64:43:09.8 |
HIP 107773 |
22.68 |
| 2026-09-20 12:00 |
21:46:24.93 |
-64:43:04.3 |
HIP 107773 |
22.98 |
| 2026-09-21 00:00 |
21:46:22.09 |
-64:42:58.6 |
HIP 107773 |
23.28 |
| 2026-09-21 12:00 |
21:46:19.27 |
-64:42:52.8 |
HIP 107773 |
23.59 |
| 2026-09-22 00:00 |
21:46:16.46 |
-64:42:46.8 |
HIP 107349 |
23.60 |
| 2026-09-22 12:00 |
21:46:13.67 |
-64:42:40.6 |
HIP 107349 |
23.55 |
| 2026-09-23 00:00 |
21:46:10.90 |
-64:42:34.3 |
HIP 107349 |
23.51 |
| 2026-09-23 12:00 |
21:46:08.14 |
-64:42:27.9 |
HIP 107349 |
23.47 |
| 2026-09-24 00:00 |
21:46:05.41 |
-64:42:21.3 |
HIP 107349 |
23.45 |
| 2026-09-24 12:00 |
21:46:02.69 |
-64:42:14.5 |
HIP 107349 |
23.43 |
| 2026-09-25 00:00 |
21:46:00.00 |
-64:42:07.6 |
HIP 107349 |
23.42 |
| 2026-09-25 12:00 |
21:45:57.31 |
-64:42:00.6 |
HIP 107349 |
23.41 |
| 2026-09-26 00:00 |
21:45:54.65 |
-64:41:53.4 |
HIP 107349 |
23.41 |
| 2026-09-26 12:00 |
21:45:52.00 |
-64:41:46.0 |
HIP 107349 |
23.42 |
| 2026-09-27 00:00 |
21:45:49.38 |
-64:41:38.5 |
HIP 107349 |
23.44 |
| 2026-09-27 12:00 |
21:45:46.77 |
-64:41:30.9 |
HIP 107349 |
23.46 |
| 2026-09-28 00:00 |
21:45:44.19 |
-64:41:23.1 |
HIP 107349 |
23.49 |
| 2026-09-28 12:00 |
21:45:41.62 |
-64:41:15.2 |
HIP 107349 |
23.53 |
| 2026-09-29 00:00 |
21:45:39.08 |
-64:41:07.1 |
HIP 107349 |
23.57 |
| 2026-09-29 12:00 |
21:45:36.55 |
-64:40:58.9 |
HIP 107349 |
23.62 |
| 2026-09-30 00:00 |
21:45:34.04 |
-64:40:50.5 |
HIP 107349 |
23.68 |
| 2026-09-30 12:00 |
21:45:31.56 |
-64:40:42.0 |
HIP 107349 |
23.74 |
| 2026-10-01 00:00 |
21:45:29.09 |
-64:40:33.4 |
HIP 107349 |
23.81 |
| 2026-10-01 12:00 |
21:45:26.65 |
-64:40:24.6 |
HIP 107349 |
23.89 |
| 2026-10-02 00:00 |
21:45:24.22 |
-64:40:15.7 |
HIP 107349 |
23.97 |
| 2026-10-02 12:00 |
21:45:21.82 |
-64:40:06.6 |
HIP 107349 |
24.06 |
| 2026-10-03 00:00 |
21:45:19.44 |
-64:39:57.4 |
HIP 107349 |
24.16 |
| 2026-10-03 12:00 |
21:45:17.08 |
-64:39:48.1 |
HIP 107349 |
24.26 |
| 2026-10-04 00:00 |
21:45:14.74 |
-64:39:38.6 |
HIP 107349 |
24.36 |
| 2026-10-04 12:00 |
21:45:12.43 |
-64:39:29.0 |
HIP 107349 |
24.48 |
| 2026-10-05 00:00 |
21:45:10.13 |
-64:39:19.2 |
HIP 107349 |
24.59 |
| 2026-10-05 12:00 |
21:45:07.86 |
-64:39:09.3 |
HIP 107349 |
24.72 |
| 2026-10-06 00:00 |
21:45:05.61 |
-64:38:59.3 |
HIP 107349 |
24.85 |
| 2026-10-06 12:00 |
21:45:03.39 |
-64:38:49.1 |
HIP 107349 |
24.98 |
| 2026-10-07 00:00 |
21:45:01.18 |
-64:38:38.8 |
HIP 107349 |
25.12 |
| 2026-10-07 12:00 |
21:44:59.00 |
-64:38:28.4 |
HIP 107349 |
25.26 |
| 2026-10-08 00:00 |
21:44:56.84 |
-64:38:17.8 |
HIP 107349 |
25.41 |
| 2026-10-08 12:00 |
21:44:54.71 |
-64:38:07.1 |
HIP 107349 |
25.57 |
| 2026-10-09 00:00 |
21:44:52.60 |
-64:37:56.3 |
HIP 107349 |
25.73 |
| 2026-10-09 12:00 |
21:44:50.51 |
-64:37:45.3 |
HIP 107349 |
25.89 |
| 2026-10-10 00:00 |
21:44:48.45 |
-64:37:34.3 |
HIP 107349 |
26.06 |
| 2026-10-10 12:00 |
21:44:46.41 |
-64:37:23.1 |
HIP 107349 |
26.23 |
| 2026-10-11 00:00 |
21:44:44.40 |
-64:37:11.7 |
HIP 107349 |
26.41 |