メタデータ
| 項目 |
値 |
| Designation |
C/1990 E1 (Cernis-Kiuchi-Nakamura) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1990-03-17T07:48:46.033920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:38Z |
| Obs used |
89 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
39.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1990-04-01.0000000 |
| e |
1.00000000 |
| q (au) |
1.068341 |
| a (au) |
- |
| i (deg) |
48.142430 |
| Ω (om, deg) |
348.444903 |
| ω (w, deg) |
100.620374 |
| M (ma, deg) |
- |
等級
散乱 + 全体線形
$$
M_a = (6.813 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
6.813 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 1990-03-17 |
1990-05-26 |
+18.7801 |
-0.670 |
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) |
| 2026-09-20 00:00 |
15:26:15.82 |
-68:36:20.6 |
HIP 75737 |
11.76 |
| 2026-09-20 12:00 |
15:26:18.83 |
-68:36:05.1 |
HIP 75737 |
11.44 |
| 2026-09-21 00:00 |
15:26:21.86 |
-68:35:49.7 |
HIP 75737 |
11.11 |
| 2026-09-21 12:00 |
15:26:24.93 |
-68:35:34.5 |
HIP 75737 |
10.79 |
| 2026-09-22 00:00 |
15:26:28.04 |
-68:35:19.4 |
HIP 75737 |
10.47 |
| 2026-09-22 12:00 |
15:26:31.18 |
-68:35:04.5 |
HIP 75737 |
10.14 |
| 2026-09-23 00:00 |
15:26:34.35 |
-68:34:49.7 |
HIP 75737 |
9.82 |
| 2026-09-23 12:00 |
15:26:37.56 |
-68:34:35.0 |
HIP 75737 |
9.51 |
| 2026-09-24 00:00 |
15:26:40.80 |
-68:34:20.5 |
HIP 75737 |
9.19 |
| 2026-09-24 12:00 |
15:26:44.08 |
-68:34:06.1 |
HIP 75737 |
8.87 |
| 2026-09-25 00:00 |
15:26:47.38 |
-68:33:51.9 |
HIP 75737 |
8.56 |
| 2026-09-25 12:00 |
15:26:50.72 |
-68:33:37.8 |
HIP 75737 |
8.25 |
| 2026-09-26 00:00 |
15:26:54.10 |
-68:33:23.9 |
HIP 75737 |
7.95 |
| 2026-09-26 12:00 |
15:26:57.50 |
-68:33:10.1 |
HIP 75737 |
7.64 |
| 2026-09-27 00:00 |
15:27:00.94 |
-68:32:56.5 |
HIP 75737 |
7.35 |
| 2026-09-27 12:00 |
15:27:04.41 |
-68:32:43.0 |
HIP 75737 |
7.06 |
| 2026-09-28 00:00 |
15:27:07.91 |
-68:32:29.7 |
HIP 75737 |
6.77 |
| 2026-09-28 12:00 |
15:27:11.45 |
-68:32:16.5 |
HIP 75737 |
6.49 |
| 2026-09-29 00:00 |
15:27:15.01 |
-68:32:03.5 |
HIP 75737 |
6.22 |
| 2026-09-29 12:00 |
15:27:18.61 |
-68:31:50.6 |
HIP 75737 |
5.96 |
| 2026-09-30 00:00 |
15:27:22.23 |
-68:31:37.9 |
HIP 75737 |
5.72 |
| 2026-09-30 12:00 |
15:27:25.89 |
-68:31:25.3 |
HIP 75737 |
5.48 |
| 2026-10-01 00:00 |
15:27:29.58 |
-68:31:12.9 |
HIP 75737 |
5.26 |
| 2026-10-01 12:00 |
15:27:33.29 |
-68:31:00.6 |
HIP 75737 |
5.06 |
| 2026-10-02 00:00 |
15:27:37.04 |
-68:30:48.5 |
HIP 75737 |
4.88 |
| 2026-10-02 12:00 |
15:27:40.82 |
-68:30:36.6 |
HIP 75737 |
4.72 |
| 2026-10-03 00:00 |
15:27:44.63 |
-68:30:24.8 |
HIP 75737 |
4.59 |
| 2026-10-03 12:00 |
15:27:48.46 |
-68:30:13.2 |
HIP 75737 |
4.49 |
| 2026-10-04 00:00 |
15:27:52.33 |
-68:30:01.7 |
HIP 75737 |
4.41 |
| 2026-10-04 12:00 |
15:27:56.22 |
-68:29:50.4 |
HIP 75737 |
4.37 |
| 2026-10-05 00:00 |
15:28:00.15 |
-68:29:39.3 |
HIP 75737 |
4.36 |
| 2026-10-05 12:00 |
15:28:04.10 |
-68:29:28.3 |
HIP 75737 |
4.38 |
| 2026-10-06 00:00 |
15:28:08.08 |
-68:29:17.5 |
HIP 75737 |
4.44 |
| 2026-10-06 12:00 |
15:28:12.09 |
-68:29:06.9 |
HIP 75737 |
4.53 |
| 2026-10-07 00:00 |
15:28:16.12 |
-68:28:56.4 |
HIP 75737 |
4.66 |
| 2026-10-07 12:00 |
15:28:20.19 |
-68:28:46.1 |
HIP 75737 |
4.81 |
| 2026-10-08 00:00 |
15:28:24.28 |
-68:28:35.9 |
HIP 75737 |
4.98 |
| 2026-10-08 12:00 |
15:28:28.39 |
-68:28:25.9 |
HIP 75737 |
5.19 |
| 2026-10-09 00:00 |
15:28:32.54 |
-68:28:16.1 |
HIP 75737 |
5.41 |
| 2026-10-09 12:00 |
15:28:36.71 |
-68:28:06.5 |
HIP 75737 |
5.65 |
| 2026-10-10 00:00 |
15:28:40.90 |
-68:27:57.0 |
HIP 75737 |
5.91 |
| 2026-10-10 12:00 |
15:28:45.12 |
-68:27:47.7 |
HIP 75737 |
6.19 |
| 2026-10-11 00:00 |
15:28:49.37 |
-68:27:38.6 |
HIP 75737 |
6.47 |