メタデータ
| 項目 |
値 |
| Designation |
C/2019 A9 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-07-26T12:36:17.003520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:51Z |
| Obs used |
199 |
| NEO |
- |
| M1 |
10.300 |
| K1 |
17.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-01-14T06:23:34.368000Z |
| Discovery magnitude (MPC) |
20.30 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) |
2019-03-25.0000000 |
| e |
0.96326067 |
| q (au) |
1.426376 |
| a (au) |
38.824214 |
| i (deg) |
84.341078 |
| Ω (om, deg) |
278.368440 |
| ω (w, deg) |
237.802336 |
| M (ma, deg) |
359.496725 |
等級
散乱 + 全体線形
$$
M_a = (10.529 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.529 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.999 |
| 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 |
| 2018-12-18 |
2019-04-22 |
+6.0772 |
-2.366 |
| 2019-08-05 |
2020-06-16 |
+2.0655 |
-3.527 |
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) |
| 2026-05-12 00:00 |
18:50:45.10 |
+06:50:40.9 |
HIP 92557 |
23.12 |
| 2026-05-12 12:00 |
18:50:40.77 |
+06:51:24.6 |
HIP 92557 |
23.20 |
| 2026-05-13 00:00 |
18:50:36.39 |
+06:52:08.1 |
HIP 92557 |
23.36 |
| 2026-05-13 12:00 |
18:50:31.97 |
+06:52:51.2 |
HIP 92557 |
23.60 |
| 2026-05-14 00:00 |
18:50:27.50 |
+06:53:34.0 |
HIP 92557 |
23.93 |
| 2026-05-14 12:00 |
18:50:22.98 |
+06:54:16.5 |
HIP 92557 |
24.34 |
| 2026-05-15 00:00 |
18:50:18.42 |
+06:54:58.7 |
HIP 92557 |
24.82 |
| 2026-05-15 12:00 |
18:50:13.81 |
+06:55:40.5 |
HIP 92557 |
25.38 |
| 2026-05-16 00:00 |
18:50:09.16 |
+06:56:22.1 |
HIP 92557 |
26.00 |
| 2026-05-16 12:00 |
18:50:04.46 |
+06:57:03.2 |
HIP 92557 |
26.69 |
| 2026-05-17 00:00 |
18:49:59.72 |
+06:57:44.1 |
HIP 92557 |
27.45 |
| 2026-05-17 12:00 |
18:49:54.93 |
+06:58:24.6 |
HIP 92557 |
28.26 |
| 2026-05-18 00:00 |
18:49:50.10 |
+06:59:04.8 |
HIP 92557 |
29.12 |
| 2026-05-18 12:00 |
18:49:45.23 |
+06:59:44.6 |
HIP 92450 |
29.51 |
| 2026-05-19 00:00 |
18:49:40.32 |
+07:00:24.1 |
HIP 92450 |
29.34 |
| 2026-05-19 12:00 |
18:49:35.36 |
+07:01:03.2 |
HIP 92450 |
29.24 |
| 2026-05-20 00:00 |
18:49:30.36 |
+07:01:42.0 |
HIP 92450 |
29.22 |
| 2026-05-20 12:00 |
18:49:25.32 |
+07:02:20.4 |
HIP 92450 |
29.28 |
| 2026-05-21 00:00 |
18:49:20.24 |
+07:02:58.4 |
HIP 92450 |
29.41 |
| 2026-05-21 12:00 |
18:49:15.12 |
+07:03:36.1 |
HIP 92450 |
29.62 |
| 2026-05-22 00:00 |
18:49:09.96 |
+07:04:13.5 |
HIP 92255 |
29.80 |
| 2026-05-22 12:00 |
18:49:04.75 |
+07:04:50.4 |
HIP 92255 |
29.63 |
| 2026-05-23 00:00 |
18:48:59.51 |
+07:05:27.0 |
HIP 92255 |
29.51 |
| 2026-05-23 12:00 |
18:48:54.24 |
+07:06:03.3 |
HIP 92255 |
29.45 |
| 2026-05-24 00:00 |
18:48:48.92 |
+07:06:39.1 |
HIP 92255 |
29.45 |
| 2026-05-24 12:00 |
18:48:43.56 |
+07:07:14.6 |
HIP 92255 |
29.52 |
| 2026-05-25 00:00 |
18:48:38.17 |
+07:07:49.7 |
HIP 92255 |
29.65 |
| 2026-05-25 12:00 |
18:48:32.74 |
+07:08:24.5 |
HIP 92255 |
29.84 |
| 2026-05-26 00:00 |
18:48:27.28 |
+07:08:58.8 |
HIP 92255 |
30.09 |
| 2026-05-26 12:00 |
18:48:21.77 |
+07:09:32.8 |
HIP 92255 |
30.41 |
| 2026-05-27 00:00 |
18:48:16.24 |
+07:10:06.4 |
HIP 92255 |
30.78 |
| 2026-05-27 12:00 |
18:48:10.66 |
+07:10:39.6 |
HIP 92255 |
31.21 |
| 2026-05-28 00:00 |
18:48:05.05 |
+07:11:12.5 |
HIP 92241 |
31.70 |
| 2026-05-28 12:00 |
18:47:59.41 |
+07:11:44.9 |
HIP 92241 |
31.10 |
| 2026-05-29 00:00 |
18:47:53.74 |
+07:12:16.9 |
HIP 92241 |
30.56 |
| 2026-05-29 12:00 |
18:47:48.03 |
+07:12:48.6 |
HIP 92241 |
30.09 |
| 2026-05-30 00:00 |
18:47:42.28 |
+07:13:19.8 |
HIP 92055 |
28.75 |
| 2026-05-30 12:00 |
18:47:36.51 |
+07:13:50.7 |
HIP 92055 |
27.32 |
| 2026-05-31 00:00 |
18:47:30.70 |
+07:14:21.2 |
HIP 92055 |
25.90 |
| 2026-05-31 12:00 |
18:47:24.86 |
+07:14:51.2 |
HIP 92055 |
24.48 |
| 2026-06-01 00:00 |
18:47:18.99 |
+07:15:20.9 |
HIP 92055 |
23.07 |
| 2026-06-01 12:00 |
18:47:13.09 |
+07:15:50.2 |
HIP 92055 |
21.66 |
| 2026-06-02 00:00 |
18:47:07.15 |
+07:16:19.0 |
HIP 92055 |
20.27 |