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) |
| 2026-06-01 00:00 |
07:59:21.44 |
-52:31:17.4 |
HIP 39051 |
1.29 |
| 2026-06-01 12:00 |
07:59:28.83 |
-52:30:06.7 |
HIP 39051 |
2.65 |
| 2026-06-02 00:00 |
07:59:36.29 |
-52:28:56.7 |
HIP 39051 |
4.20 |
| 2026-06-02 12:00 |
07:59:43.82 |
-52:27:47.5 |
HIP 39051 |
5.79 |
| 2026-06-03 00:00 |
07:59:51.42 |
-52:26:39.2 |
HIP 39051 |
7.39 |
| 2026-06-03 12:00 |
07:59:59.10 |
-52:25:31.6 |
HIP 39051 |
8.99 |
| 2026-06-04 00:00 |
08:00:06.84 |
-52:24:24.8 |
HIP 39051 |
10.60 |
| 2026-06-04 12:00 |
08:00:14.65 |
-52:23:18.8 |
HIP 39051 |
12.21 |
| 2026-06-05 00:00 |
08:00:22.53 |
-52:22:13.6 |
HIP 39257 |
12.35 |
| 2026-06-05 12:00 |
08:00:30.48 |
-52:21:09.3 |
HIP 39257 |
11.54 |
| 2026-06-06 00:00 |
08:00:38.50 |
-52:20:05.7 |
HIP 39257 |
10.88 |
| 2026-06-06 12:00 |
08:00:46.58 |
-52:19:02.9 |
HIP 39257 |
10.43 |
| 2026-06-07 00:00 |
08:00:54.72 |
-52:18:01.0 |
HIP 39257 |
10.19 |
| 2026-06-07 12:00 |
08:01:02.94 |
-52:17:00.0 |
HIP 39257 |
10.19 |
| 2026-06-08 00:00 |
08:01:11.21 |
-52:15:59.6 |
HIP 39257 |
10.43 |
| 2026-06-08 12:00 |
08:01:19.55 |
-52:15:00.2 |
HIP 39257 |
10.88 |
| 2026-06-09 00:00 |
08:01:27.95 |
-52:14:01.5 |
HIP 39257 |
11.53 |
| 2026-06-09 12:00 |
08:01:36.42 |
-52:13:03.8 |
HIP 39257 |
12.34 |
| 2026-06-10 00:00 |
08:01:44.94 |
-52:12:06.8 |
HIP 39257 |
13.29 |
| 2026-06-10 12:00 |
08:01:53.53 |
-52:11:10.7 |
HIP 39257 |
14.34 |
| 2026-06-11 00:00 |
08:02:02.17 |
-52:10:15.4 |
HIP 39257 |
15.48 |
| 2026-06-11 12:00 |
08:02:10.88 |
-52:09:21.0 |
HIP 39257 |
16.68 |
| 2026-06-12 00:00 |
08:02:19.64 |
-52:08:27.5 |
HIP 39257 |
17.94 |
| 2026-06-12 12:00 |
08:02:28.46 |
-52:07:34.8 |
HIP 39257 |
19.24 |
| 2026-06-13 00:00 |
08:02:37.34 |
-52:06:43.0 |
HIP 39257 |
20.58 |
| 2026-06-13 12:00 |
08:02:46.27 |
-52:05:52.0 |
HIP 39257 |
21.94 |
| 2026-06-14 00:00 |
08:02:55.26 |
-52:05:01.9 |
HIP 39257 |
23.33 |
| 2026-06-14 12:00 |
08:03:04.31 |
-52:04:12.7 |
HIP 39338 |
24.59 |
| 2026-06-15 00:00 |
08:03:13.40 |
-52:03:24.3 |
HIP 39338 |
25.71 |
| 2026-06-15 12:00 |
08:03:22.56 |
-52:02:36.8 |
HIP 39338 |
26.86 |
| 2026-06-16 00:00 |
08:03:31.76 |
-52:01:50.2 |
HIP 39338 |
28.05 |
| 2026-06-16 12:00 |
08:03:41.01 |
-52:01:04.5 |
HIP 39338 |
29.27 |
| 2026-06-17 00:00 |
08:03:50.32 |
-52:00:19.7 |
HIP 39709 |
29.51 |
| 2026-06-17 12:00 |
08:03:59.67 |
-51:59:35.8 |
HIP 39709 |
27.99 |
| 2026-06-18 00:00 |
08:04:09.08 |
-51:58:52.7 |
HIP 39709 |
26.48 |
| 2026-06-18 12:00 |
08:04:18.53 |
-51:58:10.5 |
HIP 39709 |
24.98 |
| 2026-06-19 00:00 |
08:04:28.03 |
-51:57:29.3 |
HIP 39709 |
23.48 |
| 2026-06-19 12:00 |
08:04:37.57 |
-51:56:48.9 |
HIP 39709 |
21.99 |
| 2026-06-20 00:00 |
08:04:47.16 |
-51:56:09.4 |
HIP 39709 |
20.51 |
| 2026-06-20 12:00 |
08:04:56.80 |
-51:55:30.8 |
HIP 39709 |
19.04 |
| 2026-06-21 00:00 |
08:05:06.48 |
-51:54:53.2 |
HIP 39709 |
17.60 |
| 2026-06-21 12:00 |
08:05:16.20 |
-51:54:16.4 |
HIP 39709 |
16.17 |
| 2026-06-22 00:00 |
08:05:25.97 |
-51:53:40.5 |
HIP 39709 |
14.78 |