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) |
| 2026-07-29 00:00 |
15:24:47.62 |
-69:12:25.9 |
HIP 74966 |
30.43 |
| 2026-07-29 12:00 |
15:24:46.17 |
-69:12:03.4 |
HIP 74966 |
30.25 |
| 2026-07-30 00:00 |
15:24:44.76 |
-69:11:40.8 |
HIP 74966 |
30.08 |
| 2026-07-30 12:00 |
15:24:43.40 |
-69:11:18.3 |
HIP 74966 |
29.92 |
| 2026-07-31 00:00 |
15:24:42.08 |
-69:10:55.7 |
HIP 74966 |
29.76 |
| 2026-07-31 12:00 |
15:24:40.80 |
-69:10:33.1 |
HIP 74966 |
29.62 |
| 2026-08-01 00:00 |
15:24:39.57 |
-69:10:10.6 |
HIP 74966 |
29.48 |
| 2026-08-01 12:00 |
15:24:38.38 |
-69:09:48.0 |
HIP 74966 |
29.35 |
| 2026-08-02 00:00 |
15:24:37.24 |
-69:09:25.4 |
HIP 74966 |
29.23 |
| 2026-08-02 12:00 |
15:24:36.13 |
-69:09:02.8 |
HIP 74966 |
29.12 |
| 2026-08-03 00:00 |
15:24:35.08 |
-69:08:40.2 |
HIP 74966 |
29.02 |
| 2026-08-03 12:00 |
15:24:34.06 |
-69:08:17.6 |
HIP 74966 |
28.92 |
| 2026-08-04 00:00 |
15:24:33.10 |
-69:07:54.9 |
HIP 74966 |
28.84 |
| 2026-08-04 12:00 |
15:24:32.17 |
-69:07:32.3 |
HIP 74966 |
28.76 |
| 2026-08-05 00:00 |
15:24:31.29 |
-69:07:09.7 |
HIP 74966 |
28.69 |
| 2026-08-05 12:00 |
15:24:30.46 |
-69:06:47.1 |
HIP 74966 |
28.63 |
| 2026-08-06 00:00 |
15:24:29.67 |
-69:06:24.6 |
HIP 74966 |
28.59 |
| 2026-08-06 12:00 |
15:24:28.92 |
-69:06:02.0 |
HIP 74966 |
28.54 |
| 2026-08-07 00:00 |
15:24:28.22 |
-69:05:39.4 |
HIP 74966 |
28.51 |
| 2026-08-07 12:00 |
15:24:27.56 |
-69:05:16.8 |
HIP 74966 |
28.49 |
| 2026-08-08 00:00 |
15:24:26.95 |
-69:04:54.3 |
HIP 74966 |
28.48 |
| 2026-08-08 12:00 |
15:24:26.38 |
-69:04:31.8 |
HIP 75320 |
28.22 |
| 2026-08-09 00:00 |
15:24:25.86 |
-69:04:09.2 |
HIP 75320 |
27.85 |
| 2026-08-09 12:00 |
15:24:25.38 |
-69:03:46.7 |
HIP 75320 |
27.47 |
| 2026-08-10 00:00 |
15:24:24.95 |
-69:03:24.3 |
HIP 75320 |
27.10 |
| 2026-08-10 12:00 |
15:24:24.56 |
-69:03:01.8 |
HIP 75320 |
26.72 |
| 2026-08-11 00:00 |
15:24:24.22 |
-69:02:39.4 |
HIP 75320 |
26.35 |
| 2026-08-11 12:00 |
15:24:23.92 |
-69:02:17.0 |
HIP 75320 |
25.98 |
| 2026-08-12 00:00 |
15:24:23.66 |
-69:01:54.6 |
HIP 75320 |
25.61 |
| 2026-08-12 12:00 |
15:24:23.46 |
-69:01:32.2 |
HIP 75320 |
25.25 |
| 2026-08-13 00:00 |
15:24:23.29 |
-69:01:09.9 |
HIP 75320 |
24.88 |
| 2026-08-13 12:00 |
15:24:23.17 |
-69:00:47.6 |
HIP 75320 |
24.52 |
| 2026-08-14 00:00 |
15:24:23.10 |
-69:00:25.4 |
HIP 75320 |
24.16 |
| 2026-08-14 12:00 |
15:24:23.07 |
-69:00:03.2 |
HIP 75320 |
23.80 |
| 2026-08-15 00:00 |
15:24:23.08 |
-68:59:41.0 |
HIP 75320 |
23.44 |
| 2026-08-15 12:00 |
15:24:23.14 |
-68:59:18.9 |
HIP 75320 |
23.08 |
| 2026-08-16 00:00 |
15:24:23.25 |
-68:58:56.8 |
HIP 75320 |
22.73 |
| 2026-08-16 12:00 |
15:24:23.40 |
-68:58:34.7 |
HIP 75320 |
22.37 |
| 2026-08-17 00:00 |
15:24:23.59 |
-68:58:12.7 |
HIP 75320 |
22.02 |
| 2026-08-17 12:00 |
15:24:23.83 |
-68:57:50.7 |
HIP 75320 |
21.68 |
| 2026-08-18 00:00 |
15:24:24.11 |
-68:57:28.8 |
HIP 75320 |
21.33 |
| 2026-08-18 12:00 |
15:24:24.44 |
-68:57:07.0 |
HIP 75320 |
20.99 |
| 2026-08-19 00:00 |
15:24:24.81 |
-68:56:45.2 |
HIP 75320 |
20.65 |