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) |
| 2026-09-20 00:00 |
12:49:47.54 |
-06:21:10.5 |
HIP 62701 |
24.29 |
| 2026-09-20 12:00 |
12:49:56.36 |
-06:21:58.0 |
HIP 62701 |
23.44 |
| 2026-09-21 00:00 |
12:50:05.21 |
-06:22:45.6 |
HIP 62701 |
22.80 |
| 2026-09-21 12:00 |
12:50:14.06 |
-06:23:33.3 |
HIP 62701 |
22.38 |
| 2026-09-22 00:00 |
12:50:22.93 |
-06:24:21.1 |
HIP 62701 |
22.20 |
| 2026-09-22 12:00 |
12:50:31.81 |
-06:25:09.0 |
HIP 62701 |
22.27 |
| 2026-09-23 00:00 |
12:50:40.70 |
-06:25:56.9 |
HIP 62701 |
22.58 |
| 2026-09-23 12:00 |
12:50:49.60 |
-06:26:45.0 |
HIP 62761 |
22.61 |
| 2026-09-24 00:00 |
12:50:58.52 |
-06:27:33.1 |
HIP 62761 |
22.15 |
| 2026-09-24 12:00 |
12:51:07.45 |
-06:28:21.3 |
HIP 62761 |
21.95 |
| 2026-09-25 00:00 |
12:51:16.39 |
-06:29:09.6 |
HIP 62761 |
21.99 |
| 2026-09-25 12:00 |
12:51:25.33 |
-06:29:58.0 |
HIP 62761 |
22.29 |
| 2026-09-26 00:00 |
12:51:34.29 |
-06:30:46.4 |
HIP 62761 |
22.84 |
| 2026-09-26 12:00 |
12:51:43.26 |
-06:31:35.0 |
HIP 62761 |
23.61 |
| 2026-09-27 00:00 |
12:51:52.24 |
-06:32:23.5 |
HIP 62761 |
24.58 |
| 2026-09-27 12:00 |
12:52:01.22 |
-06:33:12.2 |
HIP 62761 |
25.74 |
| 2026-09-28 00:00 |
12:52:10.22 |
-06:34:00.9 |
HIP 62727 |
26.58 |
| 2026-09-28 12:00 |
12:52:19.22 |
-06:34:49.6 |
HIP 62727 |
27.15 |
| 2026-09-29 00:00 |
12:52:28.23 |
-06:35:38.4 |
HIP 62727 |
27.91 |
| 2026-09-29 12:00 |
12:52:37.25 |
-06:36:27.3 |
HIP 62727 |
28.85 |
| 2026-09-30 00:00 |
12:52:46.27 |
-06:37:16.2 |
HIP 62727 |
29.95 |
| 2026-09-30 12:00 |
12:52:55.30 |
-06:38:05.2 |
HIP 62851 |
29.46 |
| 2026-10-01 00:00 |
12:53:04.34 |
-06:38:54.2 |
HIP 62851 |
28.69 |
| 2026-10-01 12:00 |
12:53:13.38 |
-06:39:43.3 |
HIP 62851 |
28.09 |
| 2026-10-02 00:00 |
12:53:22.42 |
-06:40:32.4 |
HIP 62851 |
27.69 |
| 2026-10-02 12:00 |
12:53:31.47 |
-06:41:21.5 |
HIP 62851 |
27.49 |
| 2026-10-03 00:00 |
12:53:40.53 |
-06:42:10.7 |
HIP 62851 |
27.49 |
| 2026-10-03 12:00 |
12:53:49.59 |
-06:42:59.9 |
HIP 62851 |
27.71 |
| 2026-10-04 00:00 |
12:53:58.65 |
-06:43:49.1 |
HIP 63023 |
27.53 |
| 2026-10-04 12:00 |
12:54:07.72 |
-06:44:38.4 |
HIP 63023 |
27.16 |
| 2026-10-05 00:00 |
12:54:16.79 |
-06:45:27.7 |
HIP 63023 |
27.01 |
| 2026-10-05 12:00 |
12:54:25.86 |
-06:46:17.0 |
HIP 63023 |
27.06 |
| 2026-10-06 00:00 |
12:54:34.93 |
-06:47:06.3 |
HIP 63023 |
27.33 |
| 2026-10-06 12:00 |
12:54:44.00 |
-06:47:55.6 |
HIP 63023 |
27.80 |
| 2026-10-07 00:00 |
12:54:53.08 |
-06:48:45.0 |
HIP 63023 |
28.47 |
| 2026-10-07 12:00 |
12:55:02.15 |
-06:49:34.3 |
HIP 63023 |
29.32 |
| 2026-10-08 00:00 |
12:55:11.23 |
-06:50:23.7 |
HIP 63023 |
30.34 |
| 2026-10-08 12:00 |
12:55:20.30 |
-06:51:13.0 |
HIP 63023 |
31.50 |
| 2026-10-09 00:00 |
12:55:29.37 |
-06:52:02.4 |
HIP 63023 |
32.80 |
| 2026-10-09 12:00 |
12:55:38.44 |
-06:52:51.8 |
HIP 63023 |
34.22 |
| 2026-10-10 00:00 |
12:55:47.51 |
-06:53:41.1 |
HIP 63270 |
34.91 |
| 2026-10-10 12:00 |
12:55:56.58 |
-06:54:30.4 |
HIP 63270 |
32.52 |
| 2026-10-11 00:00 |
12:56:05.64 |
-06:55:19.7 |
HIP 63270 |
30.14 |