メタデータ
| 項目 |
値 |
| Designation |
C/2018 E1 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-04-17T07:44:27.119040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:40Z |
| Obs used |
227 |
| NEO |
- |
| M1 |
11.400 |
| K1 |
8.750 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-03-10T05:26:27.744000Z |
| Discovery magnitude (MPC) |
16.80 T |
| Discovery observatory (MPC) |
T05 · ATLAS-HKO, Haleakala |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-04-14.0000000 |
| e |
0.95034655 |
| q (au) |
2.705441 |
| a (au) |
54.486472 |
| i (deg) |
72.479572 |
| Ω (om, deg) |
146.840866 |
| ω (w, deg) |
299.471840 |
| M (ma, deg) |
359.991858 |
等級
散乱 + 全体線形
$$
M_a = (9.955 + 3.883\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
9.955 |
| n |
3.883 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
| 2015-08-11 |
2018-04-08 |
-0.9341 |
+0.425 |
| 2018-04-19 |
2019-04-23 |
+8.4028 |
-4.732 |
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 |
15:40:05.13 |
+52:05:37.5 |
HIP 76850 |
13.33 |
| 2026-09-20 12:00 |
15:40:11.04 |
+52:04:22.4 |
HIP 76850 |
12.71 |
| 2026-09-21 00:00 |
15:40:17.01 |
+52:03:07.6 |
HIP 76850 |
12.25 |
| 2026-09-21 12:00 |
15:40:23.04 |
+52:01:53.1 |
HIP 76850 |
11.96 |
| 2026-09-22 00:00 |
15:40:29.13 |
+52:00:39.0 |
HIP 76850 |
11.86 |
| 2026-09-22 12:00 |
15:40:35.28 |
+51:59:25.2 |
HIP 76850 |
11.95 |
| 2026-09-23 00:00 |
15:40:41.49 |
+51:58:11.7 |
HIP 76850 |
12.22 |
| 2026-09-23 12:00 |
15:40:47.76 |
+51:56:58.5 |
HIP 76850 |
12.67 |
| 2026-09-24 00:00 |
15:40:54.09 |
+51:55:45.7 |
HIP 76850 |
13.28 |
| 2026-09-24 12:00 |
15:41:00.47 |
+51:54:33.3 |
HIP 76850 |
14.03 |
| 2026-09-25 00:00 |
15:41:06.91 |
+51:53:21.2 |
HIP 76850 |
14.89 |
| 2026-09-25 12:00 |
15:41:13.41 |
+51:52:09.5 |
HIP 76850 |
15.85 |
| 2026-09-26 00:00 |
15:41:19.96 |
+51:50:58.1 |
HIP 76850 |
16.90 |
| 2026-09-26 12:00 |
15:41:26.58 |
+51:49:47.1 |
HIP 76850 |
18.01 |
| 2026-09-27 00:00 |
15:41:33.24 |
+51:48:36.4 |
HIP 76850 |
19.18 |
| 2026-09-27 12:00 |
15:41:39.97 |
+51:47:26.1 |
HIP 76850 |
20.40 |
| 2026-09-28 00:00 |
15:41:46.74 |
+51:46:16.2 |
HIP 76850 |
21.65 |
| 2026-09-28 12:00 |
15:41:53.58 |
+51:45:06.7 |
HIP 76850 |
22.94 |
| 2026-09-29 00:00 |
15:42:00.46 |
+51:43:57.5 |
HIP 76981 |
21.53 |
| 2026-09-29 12:00 |
15:42:07.41 |
+51:42:48.8 |
HIP 76981 |
20.01 |
| 2026-09-30 00:00 |
15:42:14.40 |
+51:41:40.4 |
HIP 76981 |
18.49 |
| 2026-09-30 12:00 |
15:42:21.45 |
+51:40:32.4 |
HIP 76981 |
16.99 |
| 2026-10-01 00:00 |
15:42:28.55 |
+51:39:24.8 |
HIP 76981 |
15.51 |
| 2026-10-01 12:00 |
15:42:35.71 |
+51:38:17.6 |
HIP 76981 |
14.05 |
| 2026-10-02 00:00 |
15:42:42.91 |
+51:37:10.9 |
HIP 76981 |
12.63 |
| 2026-10-02 12:00 |
15:42:50.17 |
+51:36:04.5 |
HIP 76981 |
11.25 |
| 2026-10-03 00:00 |
15:42:57.48 |
+51:34:58.5 |
HIP 76981 |
9.93 |
| 2026-10-03 12:00 |
15:43:04.84 |
+51:33:53.0 |
HIP 76981 |
8.71 |
| 2026-10-04 00:00 |
15:43:12.25 |
+51:32:47.9 |
HIP 76981 |
7.63 |
| 2026-10-04 12:00 |
15:43:19.71 |
+51:31:43.2 |
HIP 76981 |
6.76 |
| 2026-10-05 00:00 |
15:43:27.23 |
+51:30:39.0 |
HIP 76981 |
6.19 |
| 2026-10-05 12:00 |
15:43:34.79 |
+51:29:35.1 |
HIP 76981 |
6.01 |
| 2026-10-06 00:00 |
15:43:42.40 |
+51:28:31.8 |
HIP 76981 |
6.26 |
| 2026-10-06 12:00 |
15:43:50.06 |
+51:27:28.8 |
HIP 76981 |
6.88 |
| 2026-10-07 00:00 |
15:43:57.76 |
+51:26:26.3 |
HIP 76981 |
7.79 |
| 2026-10-07 12:00 |
15:44:05.52 |
+51:25:24.3 |
HIP 76981 |
8.91 |
| 2026-10-08 00:00 |
15:44:13.32 |
+51:24:22.7 |
HIP 76981 |
10.15 |
| 2026-10-08 12:00 |
15:44:21.17 |
+51:23:21.6 |
HIP 76981 |
11.49 |
| 2026-10-09 00:00 |
15:44:29.07 |
+51:22:21.0 |
HIP 76981 |
12.90 |
| 2026-10-09 12:00 |
15:44:37.01 |
+51:21:20.8 |
HIP 76981 |
14.35 |
| 2026-10-10 00:00 |
15:44:45.00 |
+51:20:21.1 |
HIP 76981 |
15.83 |
| 2026-10-10 12:00 |
15:44:53.03 |
+51:19:21.8 |
HIP 76981 |
17.34 |
| 2026-10-11 00:00 |
15:45:01.11 |
+51:18:23.1 |
HIP 76981 |
18.86 |