メタデータ
| 項目 |
値 |
| Designation |
C/2020 Y3 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-12-03T11:39:47.134080Z |
| Orbit solution date (soln_date, UTC) |
2021-09-04T23:43:08Z |
| Obs used |
380 |
| NEO |
- |
| M1 |
13.900 |
| K1 |
8.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-12-28T15:19:02.899200Z |
| Discovery magnitude (MPC) |
18.49 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) |
2021-02-25.0000000 |
| e |
0.98676697 |
| q (au) |
1.999243 |
| a (au) |
151.079720 |
| i (deg) |
83.097062 |
| Ω (om, deg) |
191.426774 |
| ω (w, deg) |
342.043610 |
| M (ma, deg) |
0.044326 |
等級
散乱 + 全体線形
$$
M_a = (13.627 + 3.107\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.627 |
| n |
3.107 |
| gf |
0.999 |
| gb |
-0.500 |
| k |
0.974 |
| δ90 |
9.994 |
| 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 |
21:59:55.75 |
+49:29:12.6 |
HIP 108577 |
21.94 |
| 2026-03-26 12:00 |
22:00:05.57 |
+49:30:18.9 |
HIP 108577 |
23.25 |
| 2026-03-27 00:00 |
22:00:15.34 |
+49:31:25.7 |
HIP 108577 |
24.65 |
| 2026-03-27 12:00 |
22:00:25.05 |
+49:32:33.1 |
HIP 108577 |
26.13 |
| 2026-03-28 00:00 |
22:00:34.71 |
+49:33:40.9 |
HIP 108577 |
27.66 |
| 2026-03-28 12:00 |
22:00:44.32 |
+49:34:49.2 |
HIP 108891 |
26.93 |
| 2026-03-29 00:00 |
22:00:53.87 |
+49:35:58.1 |
HIP 108891 |
25.21 |
| 2026-03-29 12:00 |
22:01:03.36 |
+49:37:07.3 |
HIP 108891 |
23.52 |
| 2026-03-30 00:00 |
22:01:12.80 |
+49:38:17.1 |
HIP 108891 |
21.88 |
| 2026-03-30 12:00 |
22:01:22.17 |
+49:39:27.4 |
HIP 108891 |
20.31 |
| 2026-03-31 00:00 |
22:01:31.50 |
+49:40:38.1 |
HIP 108891 |
18.81 |
| 2026-03-31 12:00 |
22:01:40.76 |
+49:41:49.3 |
HIP 108891 |
17.40 |
| 2026-04-01 00:00 |
22:01:49.97 |
+49:43:00.9 |
HIP 108891 |
16.10 |
| 2026-04-01 12:00 |
22:01:59.12 |
+49:44:13.0 |
HIP 108891 |
14.95 |
| 2026-04-02 00:00 |
22:02:08.21 |
+49:45:25.5 |
HIP 108891 |
13.98 |
| 2026-04-02 12:00 |
22:02:17.24 |
+49:46:38.5 |
HIP 108891 |
13.23 |
| 2026-04-03 00:00 |
22:02:26.21 |
+49:47:51.9 |
HIP 108914 |
12.53 |
| 2026-04-03 12:00 |
22:02:35.12 |
+49:49:05.8 |
HIP 108914 |
11.34 |
| 2026-04-04 00:00 |
22:02:43.97 |
+49:50:20.1 |
HIP 108914 |
10.38 |
| 2026-04-04 12:00 |
22:02:52.76 |
+49:51:34.8 |
HIP 108914 |
9.70 |
| 2026-04-05 00:00 |
22:03:01.48 |
+49:52:50.0 |
HIP 108914 |
9.38 |
| 2026-04-05 12:00 |
22:03:10.15 |
+49:54:05.6 |
HIP 108914 |
9.45 |
| 2026-04-06 00:00 |
22:03:18.75 |
+49:55:21.5 |
HIP 108914 |
9.88 |
| 2026-04-06 12:00 |
22:03:27.29 |
+49:56:37.9 |
HIP 108914 |
10.65 |
| 2026-04-07 00:00 |
22:03:35.77 |
+49:57:54.7 |
HIP 108914 |
11.68 |
| 2026-04-07 12:00 |
22:03:44.18 |
+49:59:11.9 |
HIP 108914 |
12.90 |
| 2026-04-08 00:00 |
22:03:52.53 |
+50:00:29.5 |
HIP 108914 |
14.27 |
| 2026-04-08 12:00 |
22:04:00.81 |
+50:01:47.5 |
HIP 108914 |
15.75 |
| 2026-04-09 00:00 |
22:04:09.03 |
+50:03:05.8 |
HIP 108914 |
17.31 |
| 2026-04-09 12:00 |
22:04:17.18 |
+50:04:24.6 |
HIP 108914 |
18.92 |
| 2026-04-10 00:00 |
22:04:25.27 |
+50:05:43.7 |
HIP 109126 |
19.31 |
| 2026-04-10 12:00 |
22:04:33.28 |
+50:07:03.2 |
HIP 109126 |
17.58 |
| 2026-04-11 00:00 |
22:04:41.24 |
+50:08:23.0 |
HIP 109126 |
15.90 |
| 2026-04-11 12:00 |
22:04:49.12 |
+50:09:43.3 |
HIP 109126 |
14.26 |
| 2026-04-12 00:00 |
22:04:56.94 |
+50:11:03.8 |
HIP 109126 |
12.68 |
| 2026-04-12 12:00 |
22:05:04.68 |
+50:12:24.8 |
HIP 109126 |
11.19 |
| 2026-04-13 00:00 |
22:05:12.36 |
+50:13:46.0 |
HIP 109114 |
9.75 |
| 2026-04-13 12:00 |
22:05:19.97 |
+50:15:07.6 |
HIP 109114 |
8.18 |
| 2026-04-14 00:00 |
22:05:27.51 |
+50:16:29.6 |
HIP 109114 |
6.75 |
| 2026-04-14 12:00 |
22:05:34.98 |
+50:17:51.8 |
HIP 109114 |
5.57 |
| 2026-04-15 00:00 |
22:05:42.37 |
+50:19:14.4 |
HIP 109114 |
4.82 |
| 2026-04-15 12:00 |
22:05:49.70 |
+50:20:37.3 |
HIP 109114 |
4.70 |
| 2026-04-16 00:00 |
22:05:56.95 |
+50:22:00.5 |
HIP 109114 |
5.26 |