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) |
| 2026-06-01 00:00 |
16:44:20.82 |
-05:01:10.6 |
HIP 81952 |
40.08 |
| 2026-06-01 12:00 |
16:44:11.27 |
-05:01:04.7 |
HIP 81952 |
40.34 |
| 2026-06-02 00:00 |
16:44:01.73 |
-05:00:59.2 |
HIP 81952 |
40.72 |
| 2026-06-02 12:00 |
16:43:52.19 |
-05:00:54.2 |
HIP 81952 |
41.23 |
| 2026-06-03 00:00 |
16:43:42.66 |
-05:00:49.7 |
HIP 81952 |
41.87 |
| 2026-06-03 12:00 |
16:43:33.13 |
-05:00:45.7 |
HIP 81952 |
42.61 |
| 2026-06-04 00:00 |
16:43:23.61 |
-05:00:42.1 |
HIP 81952 |
43.47 |
| 2026-06-04 12:00 |
16:43:14.09 |
-05:00:39.0 |
HIP 81952 |
44.43 |
| 2026-06-05 00:00 |
16:43:04.59 |
-05:00:36.3 |
HIP 81952 |
45.48 |
| 2026-06-05 12:00 |
16:42:55.10 |
-05:00:34.2 |
HIP 81952 |
46.62 |
| 2026-06-06 00:00 |
16:42:45.61 |
-05:00:32.5 |
HIP 81952 |
47.84 |
| 2026-06-06 12:00 |
16:42:36.14 |
-05:00:31.2 |
HIP 81952 |
49.14 |
| 2026-06-07 00:00 |
16:42:26.69 |
-05:00:30.5 |
HIP 81706 |
50.24 |
| 2026-06-07 12:00 |
16:42:17.24 |
-05:00:30.2 |
HIP 81706 |
49.53 |
| 2026-06-08 00:00 |
16:42:07.82 |
-05:00:30.4 |
HIP 81706 |
48.94 |
| 2026-06-08 12:00 |
16:41:58.41 |
-05:00:31.1 |
HIP 81706 |
48.47 |
| 2026-06-09 00:00 |
16:41:49.01 |
-05:00:32.3 |
HIP 81706 |
48.11 |
| 2026-06-09 12:00 |
16:41:39.64 |
-05:00:33.9 |
HIP 81706 |
47.87 |
| 2026-06-10 00:00 |
16:41:30.29 |
-05:00:36.1 |
HIP 81465 |
47.48 |
| 2026-06-10 12:00 |
16:41:20.95 |
-05:00:38.7 |
HIP 81465 |
45.16 |
| 2026-06-11 00:00 |
16:41:11.64 |
-05:00:41.8 |
HIP 81465 |
42.84 |
| 2026-06-11 12:00 |
16:41:02.35 |
-05:00:45.4 |
HIP 81465 |
40.53 |
| 2026-06-12 00:00 |
16:40:53.09 |
-05:00:49.4 |
HIP 81465 |
38.22 |
| 2026-06-12 12:00 |
16:40:43.85 |
-05:00:54.0 |
HIP 81465 |
35.92 |
| 2026-06-13 00:00 |
16:40:34.64 |
-05:00:59.0 |
HIP 81465 |
33.62 |
| 2026-06-13 12:00 |
16:40:25.45 |
-05:01:04.6 |
HIP 81465 |
31.33 |
| 2026-06-14 00:00 |
16:40:16.29 |
-05:01:10.6 |
HIP 81465 |
29.05 |
| 2026-06-14 12:00 |
16:40:07.17 |
-05:01:17.1 |
HIP 81465 |
26.78 |
| 2026-06-15 00:00 |
16:39:58.07 |
-05:01:24.1 |
HIP 81465 |
24.51 |
| 2026-06-15 12:00 |
16:39:49.01 |
-05:01:31.6 |
HIP 81465 |
22.26 |
| 2026-06-16 00:00 |
16:39:39.97 |
-05:01:39.5 |
HIP 81465 |
20.01 |
| 2026-06-16 12:00 |
16:39:30.98 |
-05:01:48.0 |
HIP 81465 |
17.77 |
| 2026-06-17 00:00 |
16:39:22.01 |
-05:01:56.9 |
HIP 81465 |
15.55 |
| 2026-06-17 12:00 |
16:39:13.09 |
-05:02:06.4 |
HIP 81465 |
13.34 |
| 2026-06-18 00:00 |
16:39:04.20 |
-05:02:16.3 |
HIP 81465 |
11.14 |
| 2026-06-18 12:00 |
16:38:55.34 |
-05:02:26.7 |
HIP 81465 |
8.97 |
| 2026-06-19 00:00 |
16:38:46.53 |
-05:02:37.6 |
HIP 81465 |
6.84 |
| 2026-06-19 12:00 |
16:38:37.76 |
-05:02:49.0 |
HIP 81465 |
4.78 |
| 2026-06-20 00:00 |
16:38:29.03 |
-05:03:00.8 |
HIP 81465 |
2.94 |
| 2026-06-20 12:00 |
16:38:20.34 |
-05:03:13.2 |
HIP 81465 |
1.99 |
| 2026-06-21 00:00 |
16:38:11.69 |
-05:03:26.0 |
HIP 81465 |
2.96 |
| 2026-06-21 12:00 |
16:38:03.09 |
-05:03:39.3 |
HIP 81465 |
4.78 |
| 2026-06-22 00:00 |
16:37:54.53 |
-05:03:53.1 |
HIP 81465 |
6.79 |