メタデータ
| 項目 |
値 |
| Designation |
C/2018 E2 (Barros) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-12-23T16:27:32.230080Z |
| Orbit solution date (soln_date, UTC) |
2022-07-06T03:12:21Z |
| Obs used |
62 |
| NEO |
- |
| M1 |
9.900 |
| K1 |
10.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-03-12T22:14:13.056000Z |
| Discovery magnitude (MPC) |
19.40 T |
| Discovery observatory (MPC) |
Y00 · SONEAR Observatory, Oliveira |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-03-25.0000000 |
| e |
0.99760072 |
| q (au) |
3.922284 |
| a (au) |
1634.776323 |
| i (deg) |
97.742513 |
| Ω (om, deg) |
67.202099 |
| ω (w, deg) |
277.481389 |
| M (ma, deg) |
0.001362 |
等級
散乱 + 全体線形
$$
M_a = (6.323 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
6.323 |
| n |
6.000 |
| gf |
0.998 |
| gb |
-0.968 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
02:43:45.29 |
+61:09:02.0 |
HIP 12817 |
20.09 |
| 2026-06-01 12:00 |
02:43:54.21 |
+61:09:55.1 |
HIP 12817 |
18.91 |
| 2026-06-02 00:00 |
02:44:03.10 |
+61:10:48.4 |
HIP 12817 |
17.74 |
| 2026-06-02 12:00 |
02:44:11.94 |
+61:11:42.1 |
HIP 12817 |
16.61 |
| 2026-06-03 00:00 |
02:44:20.75 |
+61:12:36.2 |
HIP 12817 |
15.52 |
| 2026-06-03 12:00 |
02:44:29.53 |
+61:13:30.5 |
HIP 12817 |
14.47 |
| 2026-06-04 00:00 |
02:44:38.26 |
+61:14:25.2 |
HIP 12817 |
13.48 |
| 2026-06-04 12:00 |
02:44:46.96 |
+61:15:20.2 |
HIP 12817 |
12.55 |
| 2026-06-05 00:00 |
02:44:55.62 |
+61:16:15.6 |
HIP 12817 |
11.72 |
| 2026-06-05 12:00 |
02:45:04.23 |
+61:17:11.3 |
HIP 12817 |
10.98 |
| 2026-06-06 00:00 |
02:45:12.81 |
+61:18:07.2 |
HIP 12817 |
10.38 |
| 2026-06-06 12:00 |
02:45:21.35 |
+61:19:03.6 |
HIP 12817 |
9.93 |
| 2026-06-07 00:00 |
02:45:29.85 |
+61:20:00.2 |
HIP 12817 |
9.65 |
| 2026-06-07 12:00 |
02:45:38.30 |
+61:20:57.1 |
HIP 12817 |
9.56 |
| 2026-06-08 00:00 |
02:45:46.72 |
+61:21:54.4 |
HIP 12817 |
9.66 |
| 2026-06-08 12:00 |
02:45:55.09 |
+61:22:51.9 |
HIP 12817 |
9.94 |
| 2026-06-09 00:00 |
02:46:03.41 |
+61:23:49.8 |
HIP 12817 |
10.40 |
| 2026-06-09 12:00 |
02:46:11.70 |
+61:24:48.0 |
HIP 12817 |
11.00 |
| 2026-06-10 00:00 |
02:46:19.93 |
+61:25:46.4 |
HIP 12817 |
11.74 |
| 2026-06-10 12:00 |
02:46:28.12 |
+61:26:45.2 |
HIP 12817 |
12.57 |
| 2026-06-11 00:00 |
02:46:36.27 |
+61:27:44.3 |
HIP 12817 |
13.49 |
| 2026-06-11 12:00 |
02:46:44.37 |
+61:28:43.7 |
HIP 12817 |
14.48 |
| 2026-06-12 00:00 |
02:46:52.42 |
+61:29:43.3 |
HIP 12817 |
15.52 |
| 2026-06-12 12:00 |
02:47:00.43 |
+61:30:43.3 |
HIP 12817 |
16.61 |
| 2026-06-13 00:00 |
02:47:08.38 |
+61:31:43.5 |
HIP 12817 |
17.73 |
| 2026-06-13 12:00 |
02:47:16.29 |
+61:32:44.0 |
HIP 12817 |
18.88 |
| 2026-06-14 00:00 |
02:47:24.14 |
+61:33:44.9 |
HIP 12817 |
20.05 |
| 2026-06-14 12:00 |
02:47:31.95 |
+61:34:45.9 |
HIP 12817 |
21.25 |
| 2026-06-15 00:00 |
02:47:39.70 |
+61:35:47.3 |
HIP 13171 |
20.09 |
| 2026-06-15 12:00 |
02:47:47.40 |
+61:36:48.9 |
HIP 13171 |
18.72 |
| 2026-06-16 00:00 |
02:47:55.05 |
+61:37:50.8 |
HIP 13171 |
17.34 |
| 2026-06-16 12:00 |
02:48:02.65 |
+61:38:53.0 |
HIP 13171 |
15.97 |
| 2026-06-17 00:00 |
02:48:10.19 |
+61:39:55.5 |
HIP 13171 |
14.61 |
| 2026-06-17 12:00 |
02:48:17.68 |
+61:40:58.2 |
HIP 13171 |
13.24 |
| 2026-06-18 00:00 |
02:48:25.11 |
+61:42:01.1 |
HIP 13171 |
11.87 |
| 2026-06-18 12:00 |
02:48:32.49 |
+61:43:04.3 |
HIP 13171 |
10.51 |
| 2026-06-19 00:00 |
02:48:39.81 |
+61:44:07.8 |
HIP 13171 |
9.14 |
| 2026-06-19 12:00 |
02:48:47.07 |
+61:45:11.5 |
HIP 13171 |
7.78 |
| 2026-06-20 00:00 |
02:48:54.28 |
+61:46:15.5 |
HIP 13171 |
6.42 |
| 2026-06-20 12:00 |
02:49:01.43 |
+61:47:19.7 |
HIP 13171 |
5.07 |
| 2026-06-21 00:00 |
02:49:08.52 |
+61:48:24.1 |
HIP 13171 |
3.72 |
| 2026-06-21 12:00 |
02:49:15.55 |
+61:49:28.8 |
HIP 13171 |
2.38 |
| 2026-06-22 00:00 |
02:49:22.52 |
+61:50:33.7 |
HIP 13171 |
1.10 |