メタデータ
| 項目 |
値 |
| Designation |
C/2017 U7 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-09-11T17:19:45.906240Z |
| Orbit solution date (soln_date, UTC) |
2024-05-30T01:12:17Z |
| Obs used |
915 |
| NEO |
- |
| M1 |
6.300 |
| K1 |
8.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2017-10-29T07:49:16.032000Z |
| Discovery magnitude (MPC) |
20.10 i |
| 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) |
2020-01-08.0000000 |
| e |
1.00164840 |
| q (au) |
6.417510 |
| a (au) |
-3893.179319 |
| i (deg) |
142.635219 |
| Ω (om, deg) |
276.232353 |
| ω (w, deg) |
326.068994 |
| M (ma, deg) |
0.000480 |
等級
散乱 + 全体線形
$$
M_a = (-0.376 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
-0.376 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.958 |
| 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 |
| 2017-08-18 |
2019-09-07 |
+24.0875 |
-19.664 |
| 2019-09-15 |
2022-08-03 |
+3.9040 |
-3.583 |
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 |
14:45:13.40 |
+21:53:58.9 |
HIP 72205 |
15.74 |
| 2026-06-01 12:00 |
14:45:04.97 |
+21:54:06.1 |
HIP 72205 |
17.16 |
| 2026-06-02 00:00 |
14:44:56.58 |
+21:54:12.6 |
HIP 72205 |
18.67 |
| 2026-06-02 12:00 |
14:44:48.23 |
+21:54:18.5 |
HIP 72044 |
18.78 |
| 2026-06-03 00:00 |
14:44:39.91 |
+21:54:23.7 |
HIP 72044 |
17.92 |
| 2026-06-03 12:00 |
14:44:31.64 |
+21:54:28.2 |
HIP 72044 |
17.24 |
| 2026-06-04 00:00 |
14:44:23.40 |
+21:54:32.1 |
HIP 72044 |
16.78 |
| 2026-06-04 12:00 |
14:44:15.20 |
+21:54:35.4 |
HIP 72044 |
16.53 |
| 2026-06-05 00:00 |
14:44:07.04 |
+21:54:37.9 |
HIP 72044 |
16.51 |
| 2026-06-05 12:00 |
14:43:58.92 |
+21:54:39.9 |
HIP 71954 |
16.19 |
| 2026-06-06 00:00 |
14:43:50.85 |
+21:54:41.2 |
HIP 71954 |
14.62 |
| 2026-06-06 12:00 |
14:43:42.81 |
+21:54:41.9 |
HIP 71954 |
13.14 |
| 2026-06-07 00:00 |
14:43:34.82 |
+21:54:41.9 |
HIP 71954 |
11.77 |
| 2026-06-07 12:00 |
14:43:26.87 |
+21:54:41.3 |
HIP 71954 |
10.54 |
| 2026-06-08 00:00 |
14:43:18.96 |
+21:54:40.0 |
HIP 71954 |
9.51 |
| 2026-06-08 12:00 |
14:43:11.10 |
+21:54:38.1 |
HIP 71954 |
8.73 |
| 2026-06-09 00:00 |
14:43:03.28 |
+21:54:35.6 |
HIP 71954 |
8.29 |
| 2026-06-09 12:00 |
14:42:55.50 |
+21:54:32.4 |
HIP 71954 |
8.22 |
| 2026-06-10 00:00 |
14:42:47.77 |
+21:54:28.6 |
HIP 71954 |
8.53 |
| 2026-06-10 12:00 |
14:42:40.08 |
+21:54:24.2 |
HIP 71954 |
9.17 |
| 2026-06-11 00:00 |
14:42:32.45 |
+21:54:19.1 |
HIP 71954 |
10.07 |
| 2026-06-11 12:00 |
14:42:24.85 |
+21:54:13.5 |
HIP 71954 |
11.17 |
| 2026-06-12 00:00 |
14:42:17.31 |
+21:54:07.2 |
HIP 71954 |
12.41 |
| 2026-06-12 12:00 |
14:42:09.81 |
+21:54:00.3 |
HIP 71954 |
13.75 |
| 2026-06-13 00:00 |
14:42:02.36 |
+21:53:52.7 |
HIP 71954 |
15.15 |
| 2026-06-13 12:00 |
14:41:54.96 |
+21:53:44.6 |
HIP 71954 |
16.60 |
| 2026-06-14 00:00 |
14:41:47.61 |
+21:53:35.9 |
HIP 71954 |
18.09 |
| 2026-06-14 12:00 |
14:41:40.30 |
+21:53:26.5 |
HIP 71729 |
18.89 |
| 2026-06-15 00:00 |
14:41:33.05 |
+21:53:16.5 |
HIP 71729 |
17.32 |
| 2026-06-15 12:00 |
14:41:25.85 |
+21:53:06.0 |
HIP 71729 |
15.80 |
| 2026-06-16 00:00 |
14:41:18.69 |
+21:52:54.8 |
HIP 71729 |
14.33 |
| 2026-06-16 12:00 |
14:41:11.59 |
+21:52:43.1 |
HIP 71729 |
12.92 |
| 2026-06-17 00:00 |
14:41:04.54 |
+21:52:30.8 |
HIP 71729 |
11.59 |
| 2026-06-17 12:00 |
14:40:57.55 |
+21:52:17.8 |
HIP 71729 |
10.37 |
| 2026-06-18 00:00 |
14:40:50.60 |
+21:52:04.3 |
HIP 71729 |
9.29 |
| 2026-06-18 12:00 |
14:40:43.71 |
+21:51:50.2 |
HIP 71729 |
8.40 |
| 2026-06-19 00:00 |
14:40:36.87 |
+21:51:35.6 |
HIP 71729 |
7.77 |
| 2026-06-19 12:00 |
14:40:30.09 |
+21:51:20.4 |
HIP 71729 |
7.45 |
| 2026-06-20 00:00 |
14:40:23.35 |
+21:51:04.6 |
HIP 71729 |
7.48 |
| 2026-06-20 12:00 |
14:40:16.68 |
+21:50:48.2 |
HIP 71729 |
7.84 |
| 2026-06-21 00:00 |
14:40:10.05 |
+21:50:31.3 |
HIP 71729 |
8.48 |
| 2026-06-21 12:00 |
14:40:03.49 |
+21:50:13.8 |
HIP 71729 |
9.35 |
| 2026-06-22 00:00 |
14:39:56.97 |
+21:49:55.8 |
HIP 71729 |
10.37 |