メタデータ
| 項目 |
値 |
| Designation |
C/2020 R4 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-03-01T22:27:03.700800Z |
| Orbit solution date (soln_date, UTC) |
2022-06-06T17:33:25Z |
| Obs used |
2399 |
| NEO |
- |
| M1 |
12.800 |
| K1 |
11.750 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-09-12T11:53:38.889600Z |
| Discovery magnitude (MPC) |
19.71 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) |
2021-03-13.0000000 |
| e |
0.98936453 |
| q (au) |
1.028587 |
| a (au) |
96.712911 |
| i (deg) |
164.463346 |
| Ω (om, deg) |
323.272439 |
| ω (w, deg) |
46.707930 |
| M (ma, deg) |
0.011466 |
等級
散乱 + 全体線形
$$
M_a = (12.395 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.395 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-0.526 |
| 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 |
| 2020-08-29 |
2020-11-08 |
-9.0126 |
+3.872 |
| 2020-11-08 |
2020-12-10 |
+15.0380 |
-3.885 |
| 2020-12-10 |
2021-02-27 |
+6.3925 |
-2.570 |
| 2021-03-04 |
2021-04-25 |
+19.4111 |
-2.321 |
| 2021-04-25 |
2021-06-04 |
+1.2854 |
-0.645 |
| 2021-06-04 |
2022-03-01 |
-6.4189 |
+0.769 |
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 |
08:15:47.62 |
+15:01:54.9 |
HIP 40420 |
9.57 |
| 2026-06-01 12:00 |
08:15:51.52 |
+15:01:46.4 |
HIP 40420 |
10.52 |
| 2026-06-02 00:00 |
08:15:55.46 |
+15:01:37.7 |
HIP 40420 |
11.48 |
| 2026-06-02 12:00 |
08:15:59.45 |
+15:01:28.8 |
HIP 40420 |
12.45 |
| 2026-06-03 00:00 |
08:16:03.48 |
+15:01:19.7 |
HIP 40420 |
13.43 |
| 2026-06-03 12:00 |
08:16:07.55 |
+15:01:10.4 |
HIP 40420 |
14.43 |
| 2026-06-04 00:00 |
08:16:11.66 |
+15:01:00.9 |
HIP 40420 |
15.43 |
| 2026-06-04 12:00 |
08:16:15.82 |
+15:00:51.2 |
HIP 40420 |
16.44 |
| 2026-06-05 00:00 |
08:16:20.01 |
+15:00:41.3 |
HIP 40420 |
17.47 |
| 2026-06-05 12:00 |
08:16:24.24 |
+15:00:31.2 |
HIP 40420 |
18.50 |
| 2026-06-06 00:00 |
08:16:28.52 |
+15:00:21.0 |
HIP 40420 |
19.54 |
| 2026-06-06 12:00 |
08:16:32.83 |
+15:00:10.5 |
HIP 40420 |
20.60 |
| 2026-06-07 00:00 |
08:16:37.18 |
+14:59:59.9 |
HIP 40420 |
21.66 |
| 2026-06-07 12:00 |
08:16:41.57 |
+14:59:49.0 |
HIP 40420 |
22.74 |
| 2026-06-08 00:00 |
08:16:46.00 |
+14:59:38.0 |
HIP 40420 |
23.82 |
| 2026-06-08 12:00 |
08:16:50.47 |
+14:59:26.8 |
HIP 40420 |
24.91 |
| 2026-06-09 00:00 |
08:16:54.98 |
+14:59:15.4 |
HIP 40420 |
26.02 |
| 2026-06-09 12:00 |
08:16:59.52 |
+14:59:03.8 |
HIP 40420 |
27.13 |
| 2026-06-10 00:00 |
08:17:04.10 |
+14:58:52.0 |
HIP 40420 |
28.25 |
| 2026-06-10 12:00 |
08:17:08.72 |
+14:58:40.1 |
HIP 40420 |
29.38 |
| 2026-06-11 00:00 |
08:17:13.37 |
+14:58:27.9 |
HIP 40759 |
28.77 |
| 2026-06-11 12:00 |
08:17:18.06 |
+14:58:15.6 |
HIP 40759 |
27.67 |
| 2026-06-12 00:00 |
08:17:22.78 |
+14:58:03.1 |
HIP 40759 |
26.56 |
| 2026-06-12 12:00 |
08:17:27.54 |
+14:57:50.4 |
HIP 40759 |
25.45 |
| 2026-06-13 00:00 |
08:17:32.34 |
+14:57:37.5 |
HIP 40759 |
24.33 |
| 2026-06-13 12:00 |
08:17:37.17 |
+14:57:24.4 |
HIP 40759 |
23.21 |
| 2026-06-14 00:00 |
08:17:42.03 |
+14:57:11.2 |
HIP 40759 |
22.09 |
| 2026-06-14 12:00 |
08:17:46.92 |
+14:56:57.8 |
HIP 40759 |
20.98 |
| 2026-06-15 00:00 |
08:17:51.85 |
+14:56:44.2 |
HIP 40759 |
19.86 |
| 2026-06-15 12:00 |
08:17:56.82 |
+14:56:30.4 |
HIP 40759 |
18.75 |
| 2026-06-16 00:00 |
08:18:01.81 |
+14:56:16.5 |
HIP 40759 |
17.65 |
| 2026-06-16 12:00 |
08:18:06.83 |
+14:56:02.4 |
HIP 40759 |
16.56 |
| 2026-06-17 00:00 |
08:18:11.89 |
+14:55:48.1 |
HIP 40759 |
15.49 |
| 2026-06-17 12:00 |
08:18:16.98 |
+14:55:33.6 |
HIP 40759 |
14.43 |
| 2026-06-18 00:00 |
08:18:22.10 |
+14:55:18.9 |
HIP 40759 |
13.41 |
| 2026-06-18 12:00 |
08:18:27.24 |
+14:55:04.1 |
HIP 40759 |
12.43 |
| 2026-06-19 00:00 |
08:18:32.42 |
+14:54:49.2 |
HIP 40759 |
11.49 |
| 2026-06-19 12:00 |
08:18:37.63 |
+14:54:34.0 |
HIP 40759 |
10.63 |
| 2026-06-20 00:00 |
08:18:42.86 |
+14:54:18.7 |
HIP 40759 |
9.85 |
| 2026-06-20 12:00 |
08:18:48.13 |
+14:54:03.2 |
HIP 40759 |
9.18 |
| 2026-06-21 00:00 |
08:18:53.42 |
+14:53:47.6 |
HIP 40759 |
8.66 |
| 2026-06-21 12:00 |
08:18:58.73 |
+14:53:31.8 |
HIP 40759 |
8.31 |
| 2026-06-22 00:00 |
08:19:04.08 |
+14:53:15.8 |
HIP 40759 |
8.17 |