メタデータ
| 項目 |
値 |
| Designation |
C/1998 J1 (SOHO) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-05-08T14:51:07.577280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:53Z |
| Obs used |
318 |
| NEO |
- |
| M1 |
6.500 |
| K1 |
7.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1998-06-09.0000000 |
| e |
1.00017217 |
| q (au) |
0.153214 |
| a (au) |
-889.893232 |
| i (deg) |
62.931830 |
| Ω (om, deg) |
351.648559 |
| ω (w, deg) |
110.557189 |
| M (ma, deg) |
0.001165 |
等級
散乱 + 全体線形
$$
M_a = (6.621 + 2.438\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
6.621 |
| n |
2.438 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
1.000 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 1998-05-08 |
1998-05-20 |
+3.7861 |
+1.870 |
| 1998-05-20 |
1998-05-31 |
-2.0767 |
+0.554 |
| 1998-05-31 |
1998-07-02 |
+0.2386 |
-0.078 |
| 1998-07-02 |
1998-08-15 |
+14.9567 |
-2.015 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
22:32:37.11 |
-78:00:11.3 |
HIP 111049 |
15.23 |
| 2026-05-12 12:00 |
22:32:39.89 |
-78:00:40.2 |
HIP 111049 |
14.92 |
| 2026-05-13 00:00 |
22:32:42.60 |
-78:01:09.2 |
HIP 111049 |
14.61 |
| 2026-05-13 12:00 |
22:32:45.22 |
-78:01:38.3 |
HIP 111049 |
14.31 |
| 2026-05-14 00:00 |
22:32:47.76 |
-78:02:07.5 |
HIP 111049 |
14.02 |
| 2026-05-14 12:00 |
22:32:50.22 |
-78:02:36.9 |
HIP 111049 |
13.73 |
| 2026-05-15 00:00 |
22:32:52.60 |
-78:03:06.3 |
HIP 111049 |
13.46 |
| 2026-05-15 12:00 |
22:32:54.90 |
-78:03:35.8 |
HIP 111049 |
13.19 |
| 2026-05-16 00:00 |
22:32:57.12 |
-78:04:05.4 |
HIP 111049 |
12.93 |
| 2026-05-16 12:00 |
22:32:59.25 |
-78:04:35.2 |
HIP 111049 |
12.68 |
| 2026-05-17 00:00 |
22:33:01.30 |
-78:05:05.0 |
HIP 111049 |
12.45 |
| 2026-05-17 12:00 |
22:33:03.27 |
-78:05:34.9 |
HIP 111049 |
12.22 |
| 2026-05-18 00:00 |
22:33:05.16 |
-78:06:04.9 |
HIP 111049 |
12.01 |
| 2026-05-18 12:00 |
22:33:06.96 |
-78:06:34.9 |
HIP 111049 |
11.82 |
| 2026-05-19 00:00 |
22:33:08.68 |
-78:07:05.1 |
HIP 111049 |
11.63 |
| 2026-05-19 12:00 |
22:33:10.32 |
-78:07:35.3 |
HIP 111049 |
11.47 |
| 2026-05-20 00:00 |
22:33:11.87 |
-78:08:05.6 |
HIP 111049 |
11.32 |
| 2026-05-20 12:00 |
22:33:13.34 |
-78:08:36.0 |
HIP 111049 |
11.18 |
| 2026-05-21 00:00 |
22:33:14.72 |
-78:09:06.5 |
HIP 111049 |
11.07 |
| 2026-05-21 12:00 |
22:33:16.02 |
-78:09:37.0 |
HIP 111049 |
10.97 |
| 2026-05-22 00:00 |
22:33:17.23 |
-78:10:07.6 |
HIP 111049 |
10.89 |
| 2026-05-22 12:00 |
22:33:18.36 |
-78:10:38.3 |
HIP 111049 |
10.83 |
| 2026-05-23 00:00 |
22:33:19.40 |
-78:11:09.0 |
HIP 111049 |
10.78 |
| 2026-05-23 12:00 |
22:33:20.36 |
-78:11:39.8 |
HIP 111049 |
10.76 |
| 2026-05-24 00:00 |
22:33:21.23 |
-78:12:10.7 |
HIP 111049 |
10.76 |
| 2026-05-24 12:00 |
22:33:22.02 |
-78:12:41.6 |
HIP 111049 |
10.78 |
| 2026-05-25 00:00 |
22:33:22.72 |
-78:13:12.5 |
HIP 111049 |
10.82 |
| 2026-05-25 12:00 |
22:33:23.34 |
-78:13:43.5 |
HIP 111049 |
10.88 |
| 2026-05-26 00:00 |
22:33:23.86 |
-78:14:14.6 |
HIP 111049 |
10.96 |
| 2026-05-26 12:00 |
22:33:24.31 |
-78:14:45.7 |
HIP 111049 |
11.06 |
| 2026-05-27 00:00 |
22:33:24.66 |
-78:15:16.9 |
HIP 111049 |
11.18 |
| 2026-05-27 12:00 |
22:33:24.93 |
-78:15:48.1 |
HIP 111049 |
11.31 |
| 2026-05-28 00:00 |
22:33:25.11 |
-78:16:19.3 |
HIP 111049 |
11.47 |
| 2026-05-28 12:00 |
22:33:25.20 |
-78:16:50.6 |
HIP 111049 |
11.64 |
| 2026-05-29 00:00 |
22:33:25.21 |
-78:17:22.0 |
HIP 111049 |
11.83 |
| 2026-05-29 12:00 |
22:33:25.13 |
-78:17:53.3 |
HIP 111049 |
12.03 |
| 2026-05-30 00:00 |
22:33:24.96 |
-78:18:24.7 |
HIP 111049 |
12.25 |
| 2026-05-30 12:00 |
22:33:24.71 |
-78:18:56.1 |
HIP 111049 |
12.49 |
| 2026-05-31 00:00 |
22:33:24.36 |
-78:19:27.6 |
HIP 111049 |
12.74 |
| 2026-05-31 12:00 |
22:33:23.93 |
-78:19:59.1 |
HIP 111049 |
13.00 |
| 2026-06-01 00:00 |
22:33:23.41 |
-78:20:30.6 |
HIP 111049 |
13.27 |
| 2026-06-01 12:00 |
22:33:22.80 |
-78:21:02.1 |
HIP 111049 |
13.55 |
| 2026-06-02 00:00 |
22:33:22.11 |
-78:21:33.6 |
HIP 111049 |
13.85 |