C/2020 M5 (ATLAS)
メタデータ
| 項目 |
値 |
| Designation |
C/2020 M5 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-08-19T21:12:41.952960Z |
| Orbit solution date (soln_date, UTC) |
2023-03-28T19:42:35Z |
| Obs used |
1605 |
| NEO |
- |
| M1 |
7.600 |
| K1 |
11.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-06-30T13:19:39.388800Z |
| Discovery magnitude (MPC) |
19.44 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) |
2021-08-02.0000000 |
| e |
0.99994908 |
| q (au) |
3.004334 |
| a (au) |
59004.546918 |
| i (deg) |
93.222721 |
| Ω (om, deg) |
352.095028 |
| ω (w, deg) |
126.340033 |
| M (ma, deg) |
359.999999 |
等級
散乱 + 全体線形
$$
M_a = (8.967 + 5.727\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.967 |
| n |
5.727 |
| gf |
1.000 |
| gb |
-0.785 |
| k |
0.800 |
| 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 |
| 2019-08-10 |
2021-08-18 |
+1.0283 |
-0.456 |
| 2021-08-23 |
2022-02-06 |
-4.3432 |
+1.747 |
| 2022-02-06 |
2022-04-28 |
-5.1639 |
+2.582 |
| 2022-04-28 |
2023-02-27 |
-0.1853 |
-0.920 |
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) |
| 2026-02-03 00:00 |
08:24:50.59 |
-58:30:02.5 |
HIP 41238 |
4.77 |
| 2026-02-03 12:00 |
08:24:30.60 |
-58:29:45.3 |
HIP 41238 |
5.35 |
| 2026-02-04 00:00 |
08:24:10.65 |
-58:29:26.9 |
HIP 41238 |
6.93 |
| 2026-02-04 12:00 |
08:23:50.74 |
-58:29:07.0 |
HIP 41238 |
9.00 |
| 2026-02-05 00:00 |
08:23:30.87 |
-58:28:45.8 |
HIP 41054 |
8.27 |
| 2026-02-05 12:00 |
08:23:11.04 |
-58:28:23.2 |
HIP 41054 |
6.48 |
| 2026-02-06 00:00 |
08:22:51.26 |
-58:27:59.3 |
HIP 41054 |
5.43 |
| 2026-02-06 12:00 |
08:22:31.53 |
-58:27:34.1 |
HIP 41054 |
5.56 |
| 2026-02-07 00:00 |
08:22:11.85 |
-58:27:07.5 |
HIP 41054 |
6.79 |
| 2026-02-07 12:00 |
08:21:52.21 |
-58:26:39.5 |
HIP 41054 |
8.67 |
| 2026-02-08 00:00 |
08:21:32.64 |
-58:26:10.2 |
HIP 41054 |
10.87 |
| 2026-02-08 12:00 |
08:21:13.11 |
-58:25:39.6 |
HIP 41054 |
13.22 |
| 2026-02-09 00:00 |
08:20:53.65 |
-58:25:07.7 |
HIP 41054 |
15.65 |
| 2026-02-09 12:00 |
08:20:34.24 |
-58:24:34.4 |
HIP 41054 |
18.14 |
| 2026-02-10 00:00 |
08:20:14.89 |
-58:23:59.8 |
HIP 41054 |
20.66 |
| 2026-02-10 12:00 |
08:19:55.61 |
-58:23:23.9 |
HIP 41054 |
23.19 |
| 2026-02-11 00:00 |
08:19:36.39 |
-58:22:46.7 |
HIP 40621 |
24.86 |
| 2026-02-11 12:00 |
08:19:17.24 |
-58:22:08.3 |
HIP 40621 |
23.86 |
| 2026-02-12 00:00 |
08:18:58.16 |
-58:21:28.5 |
HIP 40621 |
23.14 |
| 2026-02-12 12:00 |
08:18:39.15 |
-58:20:47.4 |
HIP 40621 |
22.70 |
| 2026-02-13 00:00 |
08:18:20.21 |
-58:20:05.1 |
HIP 40621 |
22.58 |
| 2026-02-13 12:00 |
08:18:01.35 |
-58:19:21.5 |
HIP 40621 |
22.77 |
| 2026-02-14 00:00 |
08:17:42.56 |
-58:18:36.6 |
HIP 40621 |
23.27 |
| 2026-02-14 12:00 |
08:17:23.85 |
-58:17:50.5 |
HIP 40382 |
23.02 |
| 2026-02-15 00:00 |
08:17:05.22 |
-58:17:03.1 |
HIP 40382 |
20.45 |
| 2026-02-15 12:00 |
08:16:46.67 |
-58:16:14.5 |
HIP 40382 |
17.88 |
| 2026-02-16 00:00 |
08:16:28.21 |
-58:15:24.7 |
HIP 40382 |
15.32 |
| 2026-02-16 12:00 |
08:16:09.83 |
-58:14:33.6 |
HIP 40382 |
12.75 |
| 2026-02-17 00:00 |
08:15:51.54 |
-58:13:41.3 |
HIP 40382 |
10.20 |
| 2026-02-17 12:00 |
08:15:33.34 |
-58:12:47.8 |
HIP 40382 |
7.64 |
| 2026-02-18 00:00 |
08:15:15.23 |
-58:11:53.1 |
HIP 40382 |
5.09 |
| 2026-02-18 12:00 |
08:14:57.21 |
-58:10:57.2 |
HIP 40382 |
2.54 |
| 2026-02-19 00:00 |
08:14:39.28 |
-58:10:00.1 |
HIP 40382 |
0.18 |
| 2026-02-19 12:00 |
08:14:21.45 |
-58:09:01.9 |
HIP 40382 |
2.56 |
| 2026-02-20 00:00 |
08:14:03.72 |
-58:08:02.5 |
HIP 40382 |
5.10 |
| 2026-02-20 12:00 |
08:13:46.08 |
-58:07:02.0 |
HIP 40382 |
7.63 |
| 2026-02-21 00:00 |
08:13:28.55 |
-58:06:00.3 |
HIP 40382 |
10.17 |
| 2026-02-21 12:00 |
08:13:11.12 |
-58:04:57.4 |
HIP 40382 |
12.70 |
| 2026-02-22 00:00 |
08:12:53.79 |
-58:03:53.5 |
HIP 40382 |
15.22 |
| 2026-02-22 12:00 |
08:12:36.57 |
-58:02:48.4 |
HIP 40382 |
17.74 |
| 2026-02-23 00:00 |
08:12:19.45 |
-58:01:42.3 |
HIP 40310 |
19.96 |
| 2026-02-23 12:00 |
08:12:02.44 |
-58:00:35.0 |
HIP 40310 |
20.65 |
| 2026-02-24 00:00 |
08:11:45.54 |
-57:59:26.7 |
HIP 40310 |
21.58 |