C/2020 X2 (ATLAS)
メタデータ
| 項目 |
値 |
| Designation |
C/2020 X2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-11-15T21:24:26.968320Z |
| Orbit solution date (soln_date, UTC) |
2024-01-04T23:42:39Z |
| Obs used |
253 |
| NEO |
- |
| M1 |
7.000 |
| K1 |
16.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-12-10T12:05:53.462400Z |
| Discovery magnitude (MPC) |
18.27 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2020-12-19.0000000 |
| e |
0.76624465 |
| q (au) |
3.828504 |
| a (au) |
16.378251 |
| i (deg) |
18.191452 |
| Ω (om, deg) |
105.458856 |
| ω (w, deg) |
347.357421 |
| M (ma, deg) |
0.492307 |
等級
散乱 + 全体線形
$$
M_a = (7.669 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
7.669 |
| n |
6.000 |
| gf |
0.990 |
| gb |
-0.845 |
| k |
0.998 |
| δ90 |
1.018 |
| 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) |
| 2026-02-03 00:00 |
15:03:33.79 |
+00:18:29.3 |
HIP 73757 |
25.26 |
| 2026-02-03 12:00 |
15:03:36.35 |
+00:18:58.5 |
HIP 73757 |
24.48 |
| 2026-02-04 00:00 |
15:03:38.83 |
+00:19:28.1 |
HIP 73757 |
23.71 |
| 2026-02-04 12:00 |
15:03:41.23 |
+00:19:58.0 |
HIP 73757 |
22.95 |
| 2026-02-05 00:00 |
15:03:43.54 |
+00:20:28.4 |
HIP 73757 |
22.20 |
| 2026-02-05 12:00 |
15:03:45.78 |
+00:20:59.2 |
HIP 73757 |
21.46 |
| 2026-02-06 00:00 |
15:03:47.93 |
+00:21:30.4 |
HIP 73757 |
20.73 |
| 2026-02-06 12:00 |
15:03:50.00 |
+00:22:02.0 |
HIP 73757 |
20.00 |
| 2026-02-07 00:00 |
15:03:51.99 |
+00:22:33.9 |
HIP 73757 |
19.28 |
| 2026-02-07 12:00 |
15:03:53.89 |
+00:23:06.3 |
HIP 73757 |
18.56 |
| 2026-02-08 00:00 |
15:03:55.72 |
+00:23:39.0 |
HIP 73757 |
17.86 |
| 2026-02-08 12:00 |
15:03:57.46 |
+00:24:12.1 |
HIP 73757 |
17.15 |
| 2026-02-09 00:00 |
15:03:59.12 |
+00:24:45.6 |
HIP 73757 |
16.46 |
| 2026-02-09 12:00 |
15:04:00.69 |
+00:25:19.5 |
HIP 73757 |
15.77 |
| 2026-02-10 00:00 |
15:04:02.18 |
+00:25:53.7 |
HIP 73757 |
15.09 |
| 2026-02-10 12:00 |
15:04:03.59 |
+00:26:28.3 |
HIP 73757 |
14.42 |
| 2026-02-11 00:00 |
15:04:04.92 |
+00:27:03.2 |
HIP 73757 |
13.75 |
| 2026-02-11 12:00 |
15:04:06.16 |
+00:27:38.6 |
HIP 73757 |
13.09 |
| 2026-02-12 00:00 |
15:04:07.32 |
+00:28:14.3 |
HIP 73757 |
12.43 |
| 2026-02-12 12:00 |
15:04:08.39 |
+00:28:50.3 |
HIP 73757 |
11.79 |
| 2026-02-13 00:00 |
15:04:09.38 |
+00:29:26.7 |
HIP 73757 |
11.15 |
| 2026-02-13 12:00 |
15:04:10.29 |
+00:30:03.4 |
HIP 73757 |
10.52 |
| 2026-02-14 00:00 |
15:04:11.11 |
+00:30:40.5 |
HIP 73757 |
9.91 |
| 2026-02-14 12:00 |
15:04:11.85 |
+00:31:17.9 |
HIP 73757 |
9.31 |
| 2026-02-15 00:00 |
15:04:12.51 |
+00:31:55.7 |
HIP 73757 |
8.72 |
| 2026-02-15 12:00 |
15:04:13.08 |
+00:32:33.8 |
HIP 73757 |
8.16 |
| 2026-02-16 00:00 |
15:04:13.57 |
+00:33:12.2 |
HIP 73757 |
7.62 |
| 2026-02-16 12:00 |
15:04:13.97 |
+00:33:51.0 |
HIP 73757 |
7.12 |
| 2026-02-17 00:00 |
15:04:14.29 |
+00:34:30.0 |
HIP 73757 |
6.65 |
| 2026-02-17 12:00 |
15:04:14.53 |
+00:35:09.4 |
HIP 73757 |
6.24 |
| 2026-02-18 00:00 |
15:04:14.68 |
+00:35:49.1 |
HIP 73757 |
5.88 |
| 2026-02-18 12:00 |
15:04:14.74 |
+00:36:29.2 |
HIP 73757 |
5.60 |
| 2026-02-19 00:00 |
15:04:14.73 |
+00:37:09.5 |
HIP 73757 |
5.41 |
| 2026-02-19 12:00 |
15:04:14.63 |
+00:37:50.1 |
HIP 73757 |
5.31 |
| 2026-02-20 00:00 |
15:04:14.44 |
+00:38:31.0 |
HIP 73757 |
5.32 |
| 2026-02-20 12:00 |
15:04:14.17 |
+00:39:12.2 |
HIP 73757 |
5.45 |
| 2026-02-21 00:00 |
15:04:13.82 |
+00:39:53.7 |
HIP 73757 |
5.67 |
| 2026-02-21 12:00 |
15:04:13.39 |
+00:40:35.5 |
HIP 73757 |
5.99 |
| 2026-02-22 00:00 |
15:04:12.87 |
+00:41:17.5 |
HIP 73757 |
6.39 |
| 2026-02-22 12:00 |
15:04:12.26 |
+00:41:59.9 |
HIP 73757 |
6.86 |
| 2026-02-23 00:00 |
15:04:11.58 |
+00:42:42.5 |
HIP 73757 |
7.40 |
| 2026-02-23 12:00 |
15:04:10.81 |
+00:43:25.3 |
HIP 73757 |
7.98 |
| 2026-02-24 00:00 |
15:04:09.96 |
+00:44:08.5 |
HIP 73757 |
8.61 |