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 |
0.996 |
| gb |
-0.500 |
| k |
0.974 |
| δ90 |
9.985 |
| 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) |
| 2026-09-20 00:00 |
21:41:29.78 |
+53:22:19.8 |
HIP 107189 |
12.73 |
| 2026-09-20 12:00 |
21:41:21.39 |
+53:20:58.7 |
HIP 107189 |
13.11 |
| 2026-09-21 00:00 |
21:41:13.06 |
+53:19:36.9 |
HIP 107050 |
13.32 |
| 2026-09-21 12:00 |
21:41:04.80 |
+53:18:14.4 |
HIP 107050 |
11.72 |
| 2026-09-22 00:00 |
21:40:56.61 |
+53:16:51.3 |
HIP 107050 |
10.20 |
| 2026-09-22 12:00 |
21:40:48.50 |
+53:15:27.5 |
HIP 107050 |
8.79 |
| 2026-09-23 00:00 |
21:40:40.45 |
+53:14:03.1 |
HIP 107050 |
7.56 |
| 2026-09-23 12:00 |
21:40:32.48 |
+53:12:38.0 |
HIP 107050 |
6.61 |
| 2026-09-24 00:00 |
21:40:24.58 |
+53:11:12.3 |
HIP 107050 |
6.08 |
| 2026-09-24 12:00 |
21:40:16.76 |
+53:09:46.0 |
HIP 107050 |
6.08 |
| 2026-09-25 00:00 |
21:40:09.01 |
+53:08:19.0 |
HIP 107050 |
6.61 |
| 2026-09-25 12:00 |
21:40:01.33 |
+53:06:51.5 |
HIP 107050 |
7.56 |
| 2026-09-26 00:00 |
21:39:53.73 |
+53:05:23.3 |
HIP 107050 |
8.80 |
| 2026-09-26 12:00 |
21:39:46.21 |
+53:03:54.5 |
HIP 107050 |
10.22 |
| 2026-09-27 00:00 |
21:39:38.77 |
+53:02:25.2 |
HIP 107050 |
11.75 |
| 2026-09-27 12:00 |
21:39:31.40 |
+53:00:55.2 |
HIP 107050 |
13.37 |
| 2026-09-28 00:00 |
21:39:24.11 |
+52:59:24.7 |
HIP 107050 |
15.04 |
| 2026-09-28 12:00 |
21:39:16.90 |
+52:57:53.6 |
HIP 106794 |
14.80 |
| 2026-09-29 00:00 |
21:39:09.77 |
+52:56:22.0 |
HIP 106794 |
14.68 |
| 2026-09-29 12:00 |
21:39:02.72 |
+52:54:49.7 |
HIP 106794 |
14.82 |
| 2026-09-30 00:00 |
21:38:55.75 |
+52:53:17.0 |
HIP 106794 |
15.20 |
| 2026-09-30 12:00 |
21:38:48.86 |
+52:51:43.7 |
HIP 106794 |
15.81 |
| 2026-10-01 00:00 |
21:38:42.05 |
+52:50:09.8 |
HIP 106794 |
16.62 |
| 2026-10-01 12:00 |
21:38:35.33 |
+52:48:35.5 |
HIP 106794 |
17.60 |
| 2026-10-02 00:00 |
21:38:28.69 |
+52:47:00.6 |
HIP 106875 |
16.77 |
| 2026-10-02 12:00 |
21:38:22.13 |
+52:45:25.2 |
HIP 106875 |
15.44 |
| 2026-10-03 00:00 |
21:38:15.65 |
+52:43:49.3 |
HIP 106875 |
14.22 |
| 2026-10-03 12:00 |
21:38:09.26 |
+52:42:12.9 |
HIP 106875 |
13.15 |
| 2026-10-04 00:00 |
21:38:02.96 |
+52:40:36.0 |
HIP 106875 |
12.25 |
| 2026-10-04 12:00 |
21:37:56.74 |
+52:38:58.6 |
HIP 106875 |
11.58 |
| 2026-10-05 00:00 |
21:37:50.61 |
+52:37:20.7 |
HIP 106875 |
11.18 |
| 2026-10-05 12:00 |
21:37:44.56 |
+52:35:42.4 |
HIP 106875 |
11.07 |
| 2026-10-06 00:00 |
21:37:38.60 |
+52:34:03.6 |
HIP 106875 |
11.26 |
| 2026-10-06 12:00 |
21:37:32.73 |
+52:32:24.4 |
HIP 106875 |
11.74 |
| 2026-10-07 00:00 |
21:37:26.94 |
+52:30:44.7 |
HIP 106875 |
12.47 |
| 2026-10-07 12:00 |
21:37:21.25 |
+52:29:04.6 |
HIP 106875 |
13.42 |
| 2026-10-08 00:00 |
21:37:15.64 |
+52:27:24.1 |
HIP 106875 |
14.53 |
| 2026-10-08 12:00 |
21:37:10.13 |
+52:25:43.1 |
HIP 106875 |
15.79 |
| 2026-10-09 00:00 |
21:37:04.70 |
+52:24:01.8 |
HIP 106875 |
17.15 |
| 2026-10-09 12:00 |
21:36:59.37 |
+52:22:20.0 |
HIP 106875 |
18.59 |
| 2026-10-10 00:00 |
21:36:54.12 |
+52:20:37.9 |
HIP 106596 |
17.79 |
| 2026-10-10 12:00 |
21:36:48.97 |
+52:18:55.4 |
HIP 106596 |
16.18 |
| 2026-10-11 00:00 |
21:36:43.91 |
+52:17:12.5 |
HIP 106596 |
14.64 |