メタデータ
| 項目 |
値 |
| Designation |
C/2020 S2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-12-21T22:27:29.819520Z |
| Orbit solution date (soln_date, UTC) |
2022-09-27T15:42:34Z |
| Obs used |
96 |
| NEO |
- |
| M1 |
16.300 |
| K1 |
13.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-09-16T07:49:20.697600Z |
| Discovery magnitude (MPC) |
20.75 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) |
2020-10-15.0000000 |
| e |
0.82748820 |
| q (au) |
1.756056 |
| a (au) |
10.179340 |
| i (deg) |
22.397832 |
| Ω (om, deg) |
197.685362 |
| ω (w, deg) |
202.263038 |
| M (ma, deg) |
357.938311 |
等級
散乱 + 全体線形
$$
M_a = (15.508 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
15.508 |
| n |
6.000 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
1.000 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
12:37:30.00 |
-05:50:36.5 |
HIP 61558 |
10.63 |
| 2026-05-12 12:00 |
12:37:24.48 |
-05:49:49.2 |
HIP 61558 |
9.23 |
| 2026-05-13 00:00 |
12:37:19.01 |
-05:49:02.2 |
HIP 61558 |
7.92 |
| 2026-05-13 12:00 |
12:37:13.61 |
-05:48:15.6 |
HIP 61558 |
6.73 |
| 2026-05-14 00:00 |
12:37:08.27 |
-05:47:29.4 |
HIP 61558 |
5.73 |
| 2026-05-14 12:00 |
12:37:02.98 |
-05:46:43.5 |
HIP 61558 |
5.02 |
| 2026-05-15 00:00 |
12:36:57.76 |
-05:45:58.0 |
HIP 61558 |
4.72 |
| 2026-05-15 12:00 |
12:36:52.60 |
-05:45:12.9 |
HIP 61558 |
4.87 |
| 2026-05-16 00:00 |
12:36:47.50 |
-05:44:28.1 |
HIP 61558 |
5.44 |
| 2026-05-16 12:00 |
12:36:42.46 |
-05:43:43.8 |
HIP 61558 |
6.30 |
| 2026-05-17 00:00 |
12:36:37.49 |
-05:42:59.8 |
HIP 61558 |
7.34 |
| 2026-05-17 12:00 |
12:36:32.57 |
-05:42:16.2 |
HIP 61558 |
8.48 |
| 2026-05-18 00:00 |
12:36:27.73 |
-05:41:33.0 |
HIP 61558 |
9.68 |
| 2026-05-18 12:00 |
12:36:22.94 |
-05:40:50.2 |
HIP 61558 |
10.92 |
| 2026-05-19 00:00 |
12:36:18.22 |
-05:40:07.8 |
HIP 61558 |
12.18 |
| 2026-05-19 12:00 |
12:36:13.57 |
-05:39:25.8 |
HIP 61558 |
13.44 |
| 2026-05-20 00:00 |
12:36:08.98 |
-05:38:44.2 |
HIP 61558 |
14.70 |
| 2026-05-20 12:00 |
12:36:04.46 |
-05:38:03.0 |
HIP 61558 |
15.96 |
| 2026-05-21 00:00 |
12:36:00.00 |
-05:37:22.2 |
HIP 61558 |
17.21 |
| 2026-05-21 12:00 |
12:35:55.61 |
-05:36:41.8 |
HIP 61558 |
18.45 |
| 2026-05-22 00:00 |
12:35:51.28 |
-05:36:01.8 |
HIP 61558 |
19.68 |
| 2026-05-22 12:00 |
12:35:47.03 |
-05:35:22.3 |
HIP 61558 |
20.90 |
| 2026-05-23 00:00 |
12:35:42.83 |
-05:34:43.1 |
HIP 61558 |
22.10 |
| 2026-05-23 12:00 |
12:35:38.71 |
-05:34:04.4 |
HIP 61558 |
23.29 |
| 2026-05-24 00:00 |
12:35:34.65 |
-05:33:26.1 |
HIP 61558 |
24.47 |
| 2026-05-24 12:00 |
12:35:30.67 |
-05:32:48.3 |
HIP 61400 |
25.29 |
| 2026-05-25 00:00 |
12:35:26.74 |
-05:32:10.8 |
HIP 61400 |
24.36 |
| 2026-05-25 12:00 |
12:35:22.89 |
-05:31:33.8 |
HIP 61400 |
23.46 |
| 2026-05-26 00:00 |
12:35:19.11 |
-05:30:57.2 |
HIP 61400 |
22.60 |
| 2026-05-26 12:00 |
12:35:15.39 |
-05:30:21.1 |
HIP 61400 |
21.77 |
| 2026-05-27 00:00 |
12:35:11.75 |
-05:29:45.4 |
HIP 61400 |
20.98 |
| 2026-05-27 12:00 |
12:35:08.17 |
-05:29:10.1 |
HIP 61400 |
20.22 |
| 2026-05-28 00:00 |
12:35:04.66 |
-05:28:35.2 |
HIP 61400 |
19.51 |
| 2026-05-28 12:00 |
12:35:01.22 |
-05:28:00.8 |
HIP 61400 |
18.83 |
| 2026-05-29 00:00 |
12:34:57.85 |
-05:27:26.9 |
HIP 61400 |
18.20 |
| 2026-05-29 12:00 |
12:34:54.55 |
-05:26:53.3 |
HIP 61400 |
17.61 |
| 2026-05-30 00:00 |
12:34:51.32 |
-05:26:20.3 |
HIP 61400 |
17.06 |
| 2026-05-30 12:00 |
12:34:48.16 |
-05:25:47.6 |
HIP 61400 |
16.56 |
| 2026-05-31 00:00 |
12:34:45.07 |
-05:25:15.4 |
HIP 61400 |
16.11 |
| 2026-05-31 12:00 |
12:34:42.05 |
-05:24:43.7 |
HIP 61400 |
15.70 |
| 2026-06-01 00:00 |
12:34:39.10 |
-05:24:12.4 |
HIP 61400 |
15.34 |
| 2026-06-01 12:00 |
12:34:36.23 |
-05:23:41.6 |
HIP 61322 |
15.00 |
| 2026-06-02 00:00 |
12:34:33.42 |
-05:23:11.2 |
HIP 61322 |
14.14 |