メタデータ
| 項目 |
値 |
| Designation |
C/2020 P1 (NEOWISE) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-10-20T04:17:44.208960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:34:09Z |
| Obs used |
136 |
| NEO |
- |
| M1 |
15.300 |
| K1 |
5.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-08-02T15:00:32.832000Z |
| Discovery magnitude (MPC) |
19.00 R |
| Discovery observatory (MPC) |
C51 · WISE |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2020-09-09.0000000 |
| e |
1.00029689 |
| q (au) |
0.342183 |
| a (au) |
-1152.562177 |
| i (deg) |
45.053817 |
| Ω (om, deg) |
53.539366 |
| ω (w, deg) |
8.894962 |
| M (ma, deg) |
-0.001037 |
等級
散乱 + 全体線形
$$
M_a = (14.493 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
14.493 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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 |
| 2020-08-02 |
2020-09-20 |
+1.4276 |
-0.325 |
| 2020-09-20 |
2020-10-05 |
-8.5024 |
-2.547 |
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 |
15:04:36.92 |
-11:43:22.5 |
HIP 73760 |
3.56 |
| 2026-06-01 12:00 |
15:04:30.69 |
-11:43:04.1 |
HIP 73760 |
3.91 |
| 2026-06-02 00:00 |
15:04:24.48 |
-11:42:45.8 |
HIP 73760 |
4.77 |
| 2026-06-02 12:00 |
15:04:18.30 |
-11:42:27.8 |
HIP 73760 |
5.91 |
| 2026-06-03 00:00 |
15:04:12.15 |
-11:42:09.9 |
HIP 73760 |
7.19 |
| 2026-06-03 12:00 |
15:04:06.02 |
-11:41:52.2 |
HIP 73760 |
8.56 |
| 2026-06-04 00:00 |
15:03:59.93 |
-11:41:34.7 |
HIP 73760 |
9.96 |
| 2026-06-04 12:00 |
15:03:53.86 |
-11:41:17.4 |
HIP 73760 |
11.39 |
| 2026-06-05 00:00 |
15:03:47.82 |
-11:41:00.2 |
HIP 73760 |
12.83 |
| 2026-06-05 12:00 |
15:03:41.82 |
-11:40:43.3 |
HIP 73760 |
14.28 |
| 2026-06-06 00:00 |
15:03:35.84 |
-11:40:26.5 |
HIP 73760 |
15.73 |
| 2026-06-06 12:00 |
15:03:29.89 |
-11:40:10.0 |
HIP 73760 |
17.17 |
| 2026-06-07 00:00 |
15:03:23.98 |
-11:39:53.6 |
HIP 73760 |
18.62 |
| 2026-06-07 12:00 |
15:03:18.10 |
-11:39:37.4 |
HIP 73760 |
20.06 |
| 2026-06-08 00:00 |
15:03:12.25 |
-11:39:21.5 |
HIP 73760 |
21.50 |
| 2026-06-08 12:00 |
15:03:06.43 |
-11:39:05.7 |
HIP 73760 |
22.93 |
| 2026-06-09 00:00 |
15:03:00.65 |
-11:38:50.1 |
HIP 73760 |
24.36 |
| 2026-06-09 12:00 |
15:02:54.90 |
-11:38:34.7 |
HIP 73760 |
25.78 |
| 2026-06-10 00:00 |
15:02:49.18 |
-11:38:19.6 |
HIP 73760 |
27.19 |
| 2026-06-10 12:00 |
15:02:43.50 |
-11:38:04.6 |
HIP 73760 |
28.59 |
| 2026-06-11 00:00 |
15:02:37.85 |
-11:37:49.9 |
HIP 73760 |
29.99 |
| 2026-06-11 12:00 |
15:02:32.24 |
-11:37:35.3 |
HIP 73760 |
31.38 |
| 2026-06-12 00:00 |
15:02:26.67 |
-11:37:21.0 |
HIP 73445 |
31.93 |
| 2026-06-12 12:00 |
15:02:21.13 |
-11:37:06.9 |
HIP 73445 |
30.86 |
| 2026-06-13 00:00 |
15:02:15.63 |
-11:36:53.0 |
HIP 73445 |
29.82 |
| 2026-06-13 12:00 |
15:02:10.16 |
-11:36:39.3 |
HIP 73445 |
28.81 |
| 2026-06-14 00:00 |
15:02:04.74 |
-11:36:25.8 |
HIP 73445 |
27.84 |
| 2026-06-14 12:00 |
15:01:59.35 |
-11:36:12.5 |
HIP 73445 |
26.91 |
| 2026-06-15 00:00 |
15:01:54.00 |
-11:35:59.5 |
HIP 73445 |
26.01 |
| 2026-06-15 12:00 |
15:01:48.69 |
-11:35:46.7 |
HIP 73445 |
25.16 |
| 2026-06-16 00:00 |
15:01:43.42 |
-11:35:34.1 |
HIP 73445 |
24.36 |
| 2026-06-16 12:00 |
15:01:38.19 |
-11:35:21.7 |
HIP 73445 |
23.60 |
| 2026-06-17 00:00 |
15:01:33.00 |
-11:35:09.6 |
HIP 73445 |
22.89 |
| 2026-06-17 12:00 |
15:01:27.85 |
-11:34:57.6 |
HIP 73445 |
22.25 |
| 2026-06-18 00:00 |
15:01:22.74 |
-11:34:46.0 |
HIP 73445 |
21.65 |
| 2026-06-18 12:00 |
15:01:17.67 |
-11:34:34.5 |
HIP 73445 |
21.13 |
| 2026-06-19 00:00 |
15:01:12.64 |
-11:34:23.3 |
HIP 73445 |
20.66 |
| 2026-06-19 12:00 |
15:01:07.66 |
-11:34:12.2 |
HIP 73445 |
20.26 |
| 2026-06-20 00:00 |
15:01:02.72 |
-11:34:01.5 |
HIP 73445 |
19.93 |
| 2026-06-20 12:00 |
15:00:57.82 |
-11:33:50.9 |
HIP 73445 |
19.68 |
| 2026-06-21 00:00 |
15:00:52.97 |
-11:33:40.6 |
HIP 73445 |
19.49 |
| 2026-06-21 12:00 |
15:00:48.15 |
-11:33:30.5 |
HIP 73445 |
19.37 |
| 2026-06-22 00:00 |
15:00:43.39 |
-11:33:20.7 |
HIP 73445 |
19.33 |