メタデータ
| 項目 |
値 |
| Designation |
C/2020 S4 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-02-09T07:08:52.416960Z |
| Orbit solution date (soln_date, UTC) |
2024-07-07T00:42:12Z |
| Obs used |
1527 |
| NEO |
- |
| M1 |
10.700 |
| K1 |
6.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-09-16T12:33:54.979200Z |
| Discovery magnitude (MPC) |
21.30 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2022-06-03.0000000 |
| e |
1.00061396 |
| q (au) |
3.369605 |
| a (au) |
-5488.353502 |
| i (deg) |
20.572607 |
| Ω (om, deg) |
117.721123 |
| ω (w, deg) |
21.002074 |
| M (ma, deg) |
-0.000609 |
等級
散乱 + 全体線形
$$
M_a = (12.434 + 2.232\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.434 |
| n |
2.232 |
| gf |
1.000 |
| gb |
-0.604 |
| 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 |
| 2020-09-16 |
2022-04-14 |
+4.3248 |
-3.352 |
| 2022-04-14 |
2023-02-09 |
-3.8591 |
+1.947 |
| 2023-02-09 |
2024-02-12 |
+14.5140 |
-7.785 |
| 2024-02-12 |
2024-06-05 |
-10.6982 |
+9.545 |
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 |
16:59:07.54 |
-06:05:05.3 |
HIP 83145 |
16.51 |
| 2026-03-26 12:00 |
16:59:06.25 |
-06:04:26.0 |
HIP 83145 |
16.01 |
| 2026-03-27 00:00 |
16:59:04.86 |
-06:03:46.6 |
HIP 83145 |
15.55 |
| 2026-03-27 12:00 |
16:59:03.36 |
-06:03:07.2 |
HIP 83145 |
15.12 |
| 2026-03-28 00:00 |
16:59:01.76 |
-06:02:27.8 |
HIP 83145 |
14.72 |
| 2026-03-28 12:00 |
16:59:00.06 |
-06:01:48.4 |
HIP 83145 |
14.37 |
| 2026-03-29 00:00 |
16:58:58.26 |
-06:01:09.0 |
HIP 83145 |
14.07 |
| 2026-03-29 12:00 |
16:58:56.36 |
-06:00:29.5 |
HIP 83145 |
13.82 |
| 2026-03-30 00:00 |
16:58:54.35 |
-05:59:50.0 |
HIP 83145 |
13.63 |
| 2026-03-30 12:00 |
16:58:52.24 |
-05:59:10.6 |
HIP 83145 |
13.51 |
| 2026-03-31 00:00 |
16:58:50.03 |
-05:58:31.1 |
HIP 83145 |
13.46 |
| 2026-03-31 12:00 |
16:58:47.72 |
-05:57:51.7 |
HIP 83145 |
13.48 |
| 2026-04-01 00:00 |
16:58:45.31 |
-05:57:12.2 |
HIP 83145 |
13.58 |
| 2026-04-01 12:00 |
16:58:42.79 |
-05:56:32.8 |
HIP 83145 |
13.76 |
| 2026-04-02 00:00 |
16:58:40.18 |
-05:55:53.4 |
HIP 83145 |
14.02 |
| 2026-04-02 12:00 |
16:58:37.47 |
-05:55:14.0 |
HIP 83145 |
14.36 |
| 2026-04-03 00:00 |
16:58:34.66 |
-05:54:34.7 |
HIP 83145 |
14.77 |
| 2026-04-03 12:00 |
16:58:31.75 |
-05:53:55.3 |
HIP 83145 |
15.26 |
| 2026-04-04 00:00 |
16:58:28.74 |
-05:53:16.1 |
HIP 83145 |
15.81 |
| 2026-04-04 12:00 |
16:58:25.63 |
-05:52:36.8 |
HIP 83145 |
16.43 |
| 2026-04-05 00:00 |
16:58:22.42 |
-05:51:57.6 |
HIP 83145 |
17.11 |
| 2026-04-05 12:00 |
16:58:19.12 |
-05:51:18.5 |
HIP 83145 |
17.85 |
| 2026-04-06 00:00 |
16:58:15.71 |
-05:50:39.4 |
HIP 82961 |
18.52 |
| 2026-04-06 12:00 |
16:58:12.22 |
-05:50:00.3 |
HIP 82961 |
17.44 |
| 2026-04-07 00:00 |
16:58:08.62 |
-05:49:21.3 |
HIP 82961 |
16.34 |
| 2026-04-07 12:00 |
16:58:04.93 |
-05:48:42.4 |
HIP 82961 |
15.22 |
| 2026-04-08 00:00 |
16:58:01.14 |
-05:48:03.6 |
HIP 82961 |
14.08 |
| 2026-04-08 12:00 |
16:57:57.26 |
-05:47:24.8 |
HIP 82961 |
12.92 |
| 2026-04-09 00:00 |
16:57:53.28 |
-05:46:46.2 |
HIP 82961 |
11.74 |
| 2026-04-09 12:00 |
16:57:49.20 |
-05:46:07.6 |
HIP 82961 |
10.54 |
| 2026-04-10 00:00 |
16:57:45.04 |
-05:45:29.1 |
HIP 82961 |
9.32 |
| 2026-04-10 12:00 |
16:57:40.77 |
-05:44:50.7 |
HIP 82961 |
8.09 |
| 2026-04-11 00:00 |
16:57:36.42 |
-05:44:12.4 |
HIP 82961 |
6.83 |
| 2026-04-11 12:00 |
16:57:31.97 |
-05:43:34.2 |
HIP 82961 |
5.55 |
| 2026-04-12 00:00 |
16:57:27.43 |
-05:42:56.1 |
HIP 82961 |
4.26 |
| 2026-04-12 12:00 |
16:57:22.80 |
-05:42:18.1 |
HIP 82961 |
2.94 |
| 2026-04-13 00:00 |
16:57:18.08 |
-05:41:40.2 |
HIP 82961 |
1.61 |
| 2026-04-13 12:00 |
16:57:13.26 |
-05:41:02.5 |
HIP 82961 |
0.26 |
| 2026-04-14 00:00 |
16:57:08.36 |
-05:40:24.9 |
HIP 82961 |
1.12 |
| 2026-04-14 12:00 |
16:57:03.36 |
-05:39:47.4 |
HIP 82961 |
2.51 |
| 2026-04-15 00:00 |
16:56:58.28 |
-05:39:10.1 |
HIP 82961 |
3.91 |
| 2026-04-15 12:00 |
16:56:53.11 |
-05:38:32.9 |
HIP 82961 |
5.34 |
| 2026-04-16 00:00 |
16:56:47.85 |
-05:37:55.9 |
HIP 82961 |
6.79 |