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 |
1.000 |
| 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) |
| 2026-03-26 00:00 |
08:15:38.73 |
+14:48:14.7 |
HIP 40420 |
16.00 |
| 2026-03-26 12:00 |
08:15:34.42 |
+14:48:35.4 |
HIP 40420 |
15.24 |
| 2026-03-27 00:00 |
08:15:30.19 |
+14:48:55.8 |
HIP 40420 |
14.52 |
| 2026-03-27 12:00 |
08:15:26.02 |
+14:49:16.1 |
HIP 40420 |
13.86 |
| 2026-03-28 00:00 |
08:15:21.91 |
+14:49:36.1 |
HIP 40420 |
13.26 |
| 2026-03-28 12:00 |
08:15:17.88 |
+14:49:55.9 |
HIP 40420 |
12.72 |
| 2026-03-29 00:00 |
08:15:13.92 |
+14:50:15.5 |
HIP 40420 |
12.25 |
| 2026-03-29 12:00 |
08:15:10.02 |
+14:50:35.0 |
HIP 40420 |
11.85 |
| 2026-03-30 00:00 |
08:15:06.19 |
+14:50:54.2 |
HIP 40420 |
11.53 |
| 2026-03-30 12:00 |
08:15:02.43 |
+14:51:13.2 |
HIP 40420 |
11.29 |
| 2026-03-31 00:00 |
08:14:58.74 |
+14:51:32.0 |
HIP 40420 |
11.12 |
| 2026-03-31 12:00 |
08:14:55.12 |
+14:51:50.6 |
HIP 40420 |
11.03 |
| 2026-04-01 00:00 |
08:14:51.57 |
+14:52:09.0 |
HIP 40420 |
11.02 |
| 2026-04-01 12:00 |
08:14:48.08 |
+14:52:27.2 |
HIP 40420 |
11.08 |
| 2026-04-02 00:00 |
08:14:44.67 |
+14:52:45.2 |
HIP 40420 |
11.20 |
| 2026-04-02 12:00 |
08:14:41.32 |
+14:53:02.9 |
HIP 40420 |
11.38 |
| 2026-04-03 00:00 |
08:14:38.05 |
+14:53:20.5 |
HIP 40420 |
11.62 |
| 2026-04-03 12:00 |
08:14:34.84 |
+14:53:37.8 |
HIP 40420 |
11.90 |
| 2026-04-04 00:00 |
08:14:31.70 |
+14:53:55.0 |
HIP 40420 |
12.22 |
| 2026-04-04 12:00 |
08:14:28.63 |
+14:54:11.9 |
HIP 40420 |
12.58 |
| 2026-04-05 00:00 |
08:14:25.63 |
+14:54:28.6 |
HIP 40420 |
12.96 |
| 2026-04-05 12:00 |
08:14:22.70 |
+14:54:45.1 |
HIP 40420 |
13.37 |
| 2026-04-06 00:00 |
08:14:19.84 |
+14:55:01.4 |
HIP 40420 |
13.79 |
| 2026-04-06 12:00 |
08:14:17.05 |
+14:55:17.4 |
HIP 40420 |
14.23 |
| 2026-04-07 00:00 |
08:14:14.32 |
+14:55:33.3 |
HIP 40420 |
14.68 |
| 2026-04-07 12:00 |
08:14:11.67 |
+14:55:48.9 |
HIP 40420 |
15.13 |
| 2026-04-08 00:00 |
08:14:09.08 |
+14:56:04.4 |
HIP 40420 |
15.59 |
| 2026-04-08 12:00 |
08:14:06.57 |
+14:56:19.6 |
HIP 40420 |
16.05 |
| 2026-04-09 00:00 |
08:14:04.12 |
+14:56:34.6 |
HIP 40420 |
16.51 |
| 2026-04-09 12:00 |
08:14:01.75 |
+14:56:49.3 |
HIP 40420 |
16.96 |
| 2026-04-10 00:00 |
08:13:59.44 |
+14:57:03.9 |
HIP 40420 |
17.41 |
| 2026-04-10 12:00 |
08:13:57.20 |
+14:57:18.2 |
HIP 40420 |
17.86 |
| 2026-04-11 00:00 |
08:13:55.03 |
+14:57:32.3 |
HIP 40420 |
18.29 |
| 2026-04-11 12:00 |
08:13:52.93 |
+14:57:46.2 |
HIP 40420 |
18.72 |
| 2026-04-12 00:00 |
08:13:50.90 |
+14:57:59.9 |
HIP 40420 |
19.14 |
| 2026-04-12 12:00 |
08:13:48.94 |
+14:58:13.3 |
HIP 40420 |
19.56 |
| 2026-04-13 00:00 |
08:13:47.05 |
+14:58:26.6 |
HIP 40420 |
19.96 |
| 2026-04-13 12:00 |
08:13:45.23 |
+14:58:39.6 |
HIP 40420 |
20.35 |
| 2026-04-14 00:00 |
08:13:43.47 |
+14:58:52.3 |
HIP 40420 |
20.73 |
| 2026-04-14 12:00 |
08:13:41.79 |
+14:59:04.9 |
HIP 40420 |
21.09 |
| 2026-04-15 00:00 |
08:13:40.17 |
+14:59:17.2 |
HIP 40420 |
21.45 |
| 2026-04-15 12:00 |
08:13:38.63 |
+14:59:29.3 |
HIP 40420 |
21.79 |
| 2026-04-16 00:00 |
08:13:37.15 |
+14:59:41.2 |
HIP 40420 |
22.12 |