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) |
| 2026-03-26 00:00 |
15:42:33.49 |
-69:38:42.9 |
HIP 76595 |
20.66 |
| 2026-03-26 12:00 |
15:42:30.30 |
-69:38:58.9 |
HIP 76595 |
20.39 |
| 2026-03-27 00:00 |
15:42:27.07 |
-69:39:14.8 |
HIP 76595 |
20.12 |
| 2026-03-27 12:00 |
15:42:23.80 |
-69:39:30.5 |
HIP 76595 |
19.85 |
| 2026-03-28 00:00 |
15:42:20.49 |
-69:39:46.1 |
HIP 76595 |
19.57 |
| 2026-03-28 12:00 |
15:42:17.14 |
-69:40:01.5 |
HIP 76595 |
19.30 |
| 2026-03-29 00:00 |
15:42:13.75 |
-69:40:16.8 |
HIP 76595 |
19.03 |
| 2026-03-29 12:00 |
15:42:10.33 |
-69:40:31.9 |
HIP 76595 |
18.76 |
| 2026-03-30 00:00 |
15:42:06.87 |
-69:40:46.8 |
HIP 76595 |
18.49 |
| 2026-03-30 12:00 |
15:42:03.37 |
-69:41:01.6 |
HIP 76595 |
18.22 |
| 2026-03-31 00:00 |
15:41:59.83 |
-69:41:16.2 |
HIP 76595 |
17.96 |
| 2026-03-31 12:00 |
15:41:56.26 |
-69:41:30.7 |
HIP 76595 |
17.69 |
| 2026-04-01 00:00 |
15:41:52.65 |
-69:41:45.0 |
HIP 76595 |
17.43 |
| 2026-04-01 12:00 |
15:41:49.00 |
-69:41:59.2 |
HIP 76595 |
17.16 |
| 2026-04-02 00:00 |
15:41:45.32 |
-69:42:13.1 |
HIP 76595 |
16.90 |
| 2026-04-02 12:00 |
15:41:41.60 |
-69:42:26.9 |
HIP 76595 |
16.64 |
| 2026-04-03 00:00 |
15:41:37.84 |
-69:42:40.6 |
HIP 76595 |
16.38 |
| 2026-04-03 12:00 |
15:41:34.05 |
-69:42:54.1 |
HIP 76595 |
16.12 |
| 2026-04-04 00:00 |
15:41:30.22 |
-69:43:07.4 |
HIP 76595 |
15.87 |
| 2026-04-04 12:00 |
15:41:26.36 |
-69:43:20.5 |
HIP 76595 |
15.62 |
| 2026-04-05 00:00 |
15:41:22.47 |
-69:43:33.5 |
HIP 76595 |
15.37 |
| 2026-04-05 12:00 |
15:41:18.54 |
-69:43:46.2 |
HIP 76595 |
15.12 |
| 2026-04-06 00:00 |
15:41:14.58 |
-69:43:58.9 |
HIP 76595 |
14.88 |
| 2026-04-06 12:00 |
15:41:10.58 |
-69:44:11.3 |
HIP 76595 |
14.64 |
| 2026-04-07 00:00 |
15:41:06.55 |
-69:44:23.6 |
HIP 76595 |
14.40 |
| 2026-04-07 12:00 |
15:41:02.48 |
-69:44:35.7 |
HIP 76595 |
14.17 |
| 2026-04-08 00:00 |
15:40:58.39 |
-69:44:47.6 |
HIP 76595 |
13.94 |
| 2026-04-08 12:00 |
15:40:54.26 |
-69:44:59.3 |
HIP 76595 |
13.72 |
| 2026-04-09 00:00 |
15:40:50.10 |
-69:45:10.9 |
HIP 76595 |
13.50 |
| 2026-04-09 12:00 |
15:40:45.91 |
-69:45:22.2 |
HIP 76595 |
13.29 |
| 2026-04-10 00:00 |
15:40:41.68 |
-69:45:33.4 |
HIP 76595 |
13.08 |
| 2026-04-10 12:00 |
15:40:37.43 |
-69:45:44.4 |
HIP 76595 |
12.88 |
| 2026-04-11 00:00 |
15:40:33.14 |
-69:45:55.3 |
HIP 76595 |
12.68 |
| 2026-04-11 12:00 |
15:40:28.82 |
-69:46:05.9 |
HIP 76595 |
12.49 |
| 2026-04-12 00:00 |
15:40:24.48 |
-69:46:16.4 |
HIP 76595 |
12.31 |
| 2026-04-12 12:00 |
15:40:20.10 |
-69:46:26.6 |
HIP 76595 |
12.13 |
| 2026-04-13 00:00 |
15:40:15.70 |
-69:46:36.7 |
HIP 76595 |
11.97 |
| 2026-04-13 12:00 |
15:40:11.26 |
-69:46:46.6 |
HIP 76595 |
11.81 |
| 2026-04-14 00:00 |
15:40:06.80 |
-69:46:56.3 |
HIP 76595 |
11.66 |
| 2026-04-14 12:00 |
15:40:02.31 |
-69:47:05.8 |
HIP 76595 |
11.52 |
| 2026-04-15 00:00 |
15:39:57.79 |
-69:47:15.2 |
HIP 76595 |
11.39 |
| 2026-04-15 12:00 |
15:39:53.24 |
-69:47:24.3 |
HIP 76595 |
11.27 |
| 2026-04-16 00:00 |
15:39:48.67 |
-69:47:33.2 |
HIP 76595 |
11.16 |