メタデータ
| 項目 |
値 |
| Designation |
C/2020 S3 (Erasmus) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-12-12T16:07:52.118400Z |
| Orbit solution date (soln_date, UTC) |
2024-04-29T13:12:18Z |
| Obs used |
861 |
| NEO |
- |
| M1 |
13.000 |
| K1 |
4.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-09-17T14:40:43.536000Z |
| Discovery magnitude (MPC) |
18.48 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) |
2021-03-11.0000000 |
| e |
0.99795482 |
| q (au) |
0.398469 |
| a (au) |
194.833484 |
| i (deg) |
19.861463 |
| Ω (om, deg) |
222.992545 |
| ω (w, deg) |
349.885700 |
| M (ma, deg) |
0.032012 |
等級
散乱 + 全体線形
$$
M_a = (10.351 + 5.209\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.351 |
| n |
5.209 |
| gf |
1.000 |
| gb |
-0.884 |
| k |
0.958 |
| 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 |
| 2020-09-17 |
2020-10-17 |
+19.9753 |
-1.996 |
| 2020-10-17 |
2020-11-05 |
-0.9153 |
-0.033 |
| 2020-11-05 |
2020-12-09 |
-2.1755 |
-0.819 |
| 2020-12-18 |
2020-12-28 |
+3.4304 |
+1.116 |
| 2020-12-28 |
2021-07-09 |
-1.2828 |
-0.363 |
| 2021-07-09 |
2021-09-12 |
+18.1671 |
-11.093 |
| 2021-09-12 |
2021-11-27 |
-10.8203 |
+6.847 |
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) |
| 2026-07-29 00:00 |
01:01:18.03 |
+16:21:09.9 |
HIP 4754 |
3.07 |
| 2026-07-29 12:00 |
01:01:16.06 |
+16:21:13.0 |
HIP 4754 |
2.62 |
| 2026-07-30 00:00 |
01:01:14.04 |
+16:21:15.8 |
HIP 4754 |
2.17 |
| 2026-07-30 12:00 |
01:01:11.96 |
+16:21:18.1 |
HIP 4754 |
1.73 |
| 2026-07-31 00:00 |
01:01:09.83 |
+16:21:20.2 |
HIP 4754 |
1.35 |
| 2026-07-31 12:00 |
01:01:07.64 |
+16:21:21.8 |
HIP 4754 |
1.07 |
| 2026-08-01 00:00 |
01:01:05.40 |
+16:21:23.1 |
HIP 4754 |
1.02 |
| 2026-08-01 12:00 |
01:01:03.11 |
+16:21:24.1 |
HIP 4754 |
1.24 |
| 2026-08-02 00:00 |
01:01:00.77 |
+16:21:24.6 |
HIP 4754 |
1.64 |
| 2026-08-02 12:00 |
01:00:58.37 |
+16:21:24.8 |
HIP 4754 |
2.13 |
| 2026-08-03 00:00 |
01:00:55.92 |
+16:21:24.7 |
HIP 4754 |
2.67 |
| 2026-08-03 12:00 |
01:00:53.41 |
+16:21:24.1 |
HIP 4754 |
3.24 |
| 2026-08-04 00:00 |
01:00:50.85 |
+16:21:23.3 |
HIP 4754 |
3.84 |
| 2026-08-04 12:00 |
01:00:48.24 |
+16:21:22.0 |
HIP 4754 |
4.45 |
| 2026-08-05 00:00 |
01:00:45.58 |
+16:21:20.4 |
HIP 4754 |
5.08 |
| 2026-08-05 12:00 |
01:00:42.86 |
+16:21:18.4 |
HIP 4754 |
5.72 |
| 2026-08-06 00:00 |
01:00:40.09 |
+16:21:16.0 |
HIP 4754 |
6.38 |
| 2026-08-06 12:00 |
01:00:37.27 |
+16:21:13.3 |
HIP 4754 |
7.06 |
| 2026-08-07 00:00 |
01:00:34.40 |
+16:21:10.2 |
HIP 4754 |
7.75 |
| 2026-08-07 12:00 |
01:00:31.48 |
+16:21:06.7 |
HIP 4754 |
8.45 |
| 2026-08-08 00:00 |
01:00:28.50 |
+16:21:02.8 |
HIP 4754 |
9.16 |
| 2026-08-08 12:00 |
01:00:25.47 |
+16:20:58.6 |
HIP 4754 |
9.89 |
| 2026-08-09 00:00 |
01:00:22.39 |
+16:20:54.0 |
HIP 4754 |
10.63 |
| 2026-08-09 12:00 |
01:00:19.26 |
+16:20:49.0 |
HIP 4754 |
11.39 |
| 2026-08-10 00:00 |
01:00:16.08 |
+16:20:43.7 |
HIP 4754 |
12.16 |
| 2026-08-10 12:00 |
01:00:12.85 |
+16:20:38.0 |
HIP 4754 |
12.94 |
| 2026-08-11 00:00 |
01:00:09.56 |
+16:20:31.9 |
HIP 4754 |
13.73 |
| 2026-08-11 12:00 |
01:00:06.23 |
+16:20:25.4 |
HIP 4754 |
14.54 |
| 2026-08-12 00:00 |
01:00:02.84 |
+16:20:18.6 |
HIP 4754 |
15.36 |
| 2026-08-12 12:00 |
00:59:59.41 |
+16:20:11.4 |
HIP 4754 |
16.19 |
| 2026-08-13 00:00 |
00:59:55.93 |
+16:20:03.8 |
HIP 4754 |
17.04 |
| 2026-08-13 12:00 |
00:59:52.39 |
+16:19:55.8 |
HIP 4754 |
17.90 |
| 2026-08-14 00:00 |
00:59:48.81 |
+16:19:47.5 |
HIP 4573 |
18.52 |
| 2026-08-14 12:00 |
00:59:45.18 |
+16:19:38.7 |
HIP 4573 |
17.64 |
| 2026-08-15 00:00 |
00:59:41.50 |
+16:19:29.7 |
HIP 4573 |
16.75 |
| 2026-08-15 12:00 |
00:59:37.77 |
+16:19:20.2 |
HIP 4573 |
15.85 |
| 2026-08-16 00:00 |
00:59:33.99 |
+16:19:10.4 |
HIP 4573 |
14.94 |
| 2026-08-16 12:00 |
00:59:30.17 |
+16:19:00.2 |
HIP 4573 |
14.02 |
| 2026-08-17 00:00 |
00:59:26.30 |
+16:18:49.6 |
HIP 4573 |
13.09 |
| 2026-08-17 12:00 |
00:59:22.38 |
+16:18:38.6 |
HIP 4573 |
12.15 |
| 2026-08-18 00:00 |
00:59:18.42 |
+16:18:27.3 |
HIP 4573 |
11.21 |
| 2026-08-18 12:00 |
00:59:14.40 |
+16:18:15.6 |
HIP 4573 |
10.25 |
| 2026-08-19 00:00 |
00:59:10.35 |
+16:18:03.5 |
HIP 4573 |
9.30 |