メタデータ
| 項目 |
値 |
| Designation |
C/1999 K1 (SOHO) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1999-05-21T08:52:48Z |
| Orbit solution date (soln_date, UTC) |
- |
| Obs used |
40 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1999-05-21.3700000 |
| e |
1.00000000 |
| q (au) |
0.005100 |
| a (au) |
- |
| i (deg) |
143.780000 |
| Ω (om, deg) |
5.490000 |
| ω (w, deg) |
83.510000 |
| M (ma, deg) |
- |
等級
散乱 + 全体線形
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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 |
06:45:54.86 |
-12:34:16.8 |
HIP 32442 |
19.27 |
| 2026-05-12 12:00 |
06:45:56.35 |
-12:34:03.1 |
HIP 32442 |
19.40 |
| 2026-05-13 00:00 |
06:45:57.84 |
-12:33:49.5 |
HIP 32442 |
19.53 |
| 2026-05-13 12:00 |
06:45:59.36 |
-12:33:36.0 |
HIP 32442 |
19.67 |
| 2026-05-14 00:00 |
06:46:00.88 |
-12:33:22.7 |
HIP 32442 |
19.82 |
| 2026-05-14 12:00 |
06:46:02.42 |
-12:33:09.5 |
HIP 32442 |
19.97 |
| 2026-05-15 00:00 |
06:46:03.98 |
-12:32:56.5 |
HIP 32442 |
20.13 |
| 2026-05-15 12:00 |
06:46:05.55 |
-12:32:43.5 |
HIP 32442 |
20.30 |
| 2026-05-16 00:00 |
06:46:07.13 |
-12:32:30.7 |
HIP 32442 |
20.47 |
| 2026-05-16 12:00 |
06:46:08.73 |
-12:32:18.1 |
HIP 32442 |
20.64 |
| 2026-05-17 00:00 |
06:46:10.34 |
-12:32:05.5 |
HIP 32442 |
20.82 |
| 2026-05-17 12:00 |
06:46:11.96 |
-12:31:53.2 |
HIP 32442 |
21.01 |
| 2026-05-18 00:00 |
06:46:13.60 |
-12:31:40.9 |
HIP 32442 |
21.20 |
| 2026-05-18 12:00 |
06:46:15.25 |
-12:31:28.8 |
HIP 32442 |
21.40 |
| 2026-05-19 00:00 |
06:46:16.91 |
-12:31:16.8 |
HIP 32442 |
21.60 |
| 2026-05-19 12:00 |
06:46:18.59 |
-12:31:05.0 |
HIP 32442 |
21.81 |
| 2026-05-20 00:00 |
06:46:20.28 |
-12:30:53.3 |
HIP 32442 |
22.02 |
| 2026-05-20 12:00 |
06:46:21.98 |
-12:30:41.7 |
HIP 32513 |
21.74 |
| 2026-05-21 00:00 |
06:46:23.69 |
-12:30:30.3 |
HIP 32513 |
21.36 |
| 2026-05-21 12:00 |
06:46:25.42 |
-12:30:19.0 |
HIP 32513 |
20.99 |
| 2026-05-22 00:00 |
06:46:27.16 |
-12:30:07.8 |
HIP 32513 |
20.63 |
| 2026-05-22 12:00 |
06:46:28.91 |
-12:29:56.8 |
HIP 32513 |
20.27 |
| 2026-05-23 00:00 |
06:46:30.67 |
-12:29:46.0 |
HIP 32513 |
19.91 |
| 2026-05-23 12:00 |
06:46:32.44 |
-12:29:35.3 |
HIP 32513 |
19.56 |
| 2026-05-24 00:00 |
06:46:34.23 |
-12:29:24.7 |
HIP 32513 |
19.22 |
| 2026-05-24 12:00 |
06:46:36.03 |
-12:29:14.3 |
HIP 32513 |
18.88 |
| 2026-05-25 00:00 |
06:46:37.84 |
-12:29:04.0 |
HIP 32513 |
18.55 |
| 2026-05-25 12:00 |
06:46:39.65 |
-12:28:53.9 |
HIP 32513 |
18.22 |
| 2026-05-26 00:00 |
06:46:41.49 |
-12:28:43.9 |
HIP 32513 |
17.91 |
| 2026-05-26 12:00 |
06:46:43.33 |
-12:28:34.1 |
HIP 32513 |
17.60 |
| 2026-05-27 00:00 |
06:46:45.18 |
-12:28:24.4 |
HIP 32513 |
17.30 |
| 2026-05-27 12:00 |
06:46:47.04 |
-12:28:14.8 |
HIP 32513 |
17.02 |
| 2026-05-28 00:00 |
06:46:48.92 |
-12:28:05.4 |
HIP 32513 |
16.74 |
| 2026-05-28 12:00 |
06:46:50.80 |
-12:27:56.2 |
HIP 32513 |
16.47 |
| 2026-05-29 00:00 |
06:46:52.70 |
-12:27:47.1 |
HIP 32513 |
16.22 |
| 2026-05-29 12:00 |
06:46:54.60 |
-12:27:38.2 |
HIP 32513 |
15.98 |
| 2026-05-30 00:00 |
06:46:56.52 |
-12:27:29.4 |
HIP 32513 |
15.75 |
| 2026-05-30 12:00 |
06:46:58.44 |
-12:27:20.7 |
HIP 32513 |
15.54 |
| 2026-05-31 00:00 |
06:47:00.37 |
-12:27:12.2 |
HIP 32513 |
15.34 |
| 2026-05-31 12:00 |
06:47:02.32 |
-12:27:03.9 |
HIP 32513 |
15.16 |
| 2026-06-01 00:00 |
06:47:04.27 |
-12:26:55.7 |
HIP 32513 |
15.00 |
| 2026-06-01 12:00 |
06:47:06.24 |
-12:26:47.6 |
HIP 32513 |
14.85 |
| 2026-06-02 00:00 |
06:47:08.21 |
-12:26:39.7 |
HIP 32513 |
14.72 |