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) |
| 2026-03-26 00:00 |
15:00:56.38 |
+01:32:16.1 |
HIP 73491 |
19.35 |
| 2026-03-26 12:00 |
15:00:51.00 |
+01:33:06.0 |
HIP 73491 |
18.85 |
| 2026-03-27 00:00 |
15:00:45.56 |
+01:33:55.8 |
HIP 73491 |
18.49 |
| 2026-03-27 12:00 |
15:00:40.06 |
+01:34:45.6 |
HIP 73491 |
18.27 |
| 2026-03-28 00:00 |
15:00:34.50 |
+01:35:35.3 |
HIP 73491 |
18.19 |
| 2026-03-28 12:00 |
15:00:28.89 |
+01:36:24.9 |
HIP 73491 |
18.27 |
| 2026-03-29 00:00 |
15:00:23.21 |
+01:37:14.4 |
HIP 73491 |
18.50 |
| 2026-03-29 12:00 |
15:00:17.48 |
+01:38:03.9 |
HIP 73491 |
18.89 |
| 2026-03-30 00:00 |
15:00:11.69 |
+01:38:53.2 |
HIP 73491 |
19.42 |
| 2026-03-30 12:00 |
15:00:05.85 |
+01:39:42.5 |
HIP 73491 |
20.08 |
| 2026-03-31 00:00 |
14:59:59.95 |
+01:40:31.7 |
HIP 73491 |
20.87 |
| 2026-03-31 12:00 |
14:59:54.00 |
+01:41:20.7 |
HIP 73491 |
21.78 |
| 2026-04-01 00:00 |
14:59:47.99 |
+01:42:09.7 |
HIP 73491 |
22.79 |
| 2026-04-01 12:00 |
14:59:41.94 |
+01:42:58.5 |
HIP 73491 |
23.89 |
| 2026-04-02 00:00 |
14:59:35.82 |
+01:43:47.3 |
HIP 73491 |
25.08 |
| 2026-04-02 12:00 |
14:59:29.66 |
+01:44:35.9 |
HIP 73491 |
26.34 |
| 2026-04-03 00:00 |
14:59:23.45 |
+01:45:24.3 |
HIP 73491 |
27.66 |
| 2026-04-03 12:00 |
14:59:17.18 |
+01:46:12.6 |
HIP 73274 |
28.58 |
| 2026-04-04 00:00 |
14:59:10.87 |
+01:47:00.8 |
HIP 73274 |
27.26 |
| 2026-04-04 12:00 |
14:59:04.50 |
+01:47:48.9 |
HIP 73274 |
25.98 |
| 2026-04-05 00:00 |
14:58:58.09 |
+01:48:36.8 |
HIP 73274 |
24.77 |
| 2026-04-05 12:00 |
14:58:51.63 |
+01:49:24.5 |
HIP 73274 |
23.63 |
| 2026-04-06 00:00 |
14:58:45.12 |
+01:50:12.1 |
HIP 73274 |
22.57 |
| 2026-04-06 12:00 |
14:58:38.57 |
+01:50:59.5 |
HIP 73274 |
21.62 |
| 2026-04-07 00:00 |
14:58:31.97 |
+01:51:46.7 |
HIP 73274 |
20.79 |
| 2026-04-07 12:00 |
14:58:25.32 |
+01:52:33.7 |
HIP 73274 |
20.10 |
| 2026-04-08 00:00 |
14:58:18.63 |
+01:53:20.6 |
HIP 73274 |
19.56 |
| 2026-04-08 12:00 |
14:58:11.90 |
+01:54:07.3 |
HIP 73274 |
19.18 |
| 2026-04-09 00:00 |
14:58:05.12 |
+01:54:53.7 |
HIP 73274 |
18.99 |
| 2026-04-09 12:00 |
14:57:58.30 |
+01:55:40.0 |
HIP 73274 |
18.99 |
| 2026-04-10 00:00 |
14:57:51.44 |
+01:56:26.1 |
HIP 73274 |
19.18 |
| 2026-04-10 12:00 |
14:57:44.54 |
+01:57:12.0 |
HIP 73274 |
19.56 |
| 2026-04-11 00:00 |
14:57:37.60 |
+01:57:57.6 |
HIP 73274 |
20.12 |
| 2026-04-11 12:00 |
14:57:30.62 |
+01:58:43.1 |
HIP 73274 |
20.84 |
| 2026-04-12 00:00 |
14:57:23.60 |
+01:59:28.3 |
HIP 73274 |
21.72 |
| 2026-04-12 12:00 |
14:57:16.55 |
+02:00:13.2 |
HIP 73274 |
22.73 |
| 2026-04-13 00:00 |
14:57:09.45 |
+02:00:58.0 |
HIP 73274 |
23.87 |
| 2026-04-13 12:00 |
14:57:02.32 |
+02:01:42.4 |
HIP 73274 |
25.11 |
| 2026-04-14 00:00 |
14:56:55.16 |
+02:02:26.7 |
HIP 73274 |
26.45 |
| 2026-04-14 12:00 |
14:56:47.96 |
+02:03:10.7 |
HIP 73274 |
27.86 |
| 2026-04-15 00:00 |
14:56:40.73 |
+02:03:54.4 |
HIP 73274 |
29.34 |
| 2026-04-15 12:00 |
14:56:33.46 |
+02:04:37.9 |
HIP 73274 |
30.89 |
| 2026-04-16 00:00 |
14:56:26.16 |
+02:05:21.1 |
HIP 72988 |
29.95 |