メタデータ
| 項目 |
値 |
| Designation |
P/2021 C2 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-02-24T15:22:00.105600Z |
| Orbit solution date (soln_date, UTC) |
2021-10-18T22:42:46Z |
| Obs used |
55 |
| NEO |
- |
| M1 |
11.400 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-02-12T12:41:22.185600Z |
| Discovery magnitude (MPC) |
22.16 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) |
2021-03-19.0000000 |
| e |
0.48743656 |
| q (au) |
4.890288 |
| a (au) |
9.540845 |
| i (deg) |
21.926912 |
| Ω (om, deg) |
66.498296 |
| ω (w, deg) |
78.823510 |
| M (ma, deg) |
0.747808 |
等級
散乱 + 全体線形
$$
M_a = (13.932 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.932 |
| n |
2.000 |
| gf |
0.999 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
17:44:40.08 |
-31:30:04.3 |
HIP 87022 |
28.63 |
| 2026-06-01 12:00 |
17:44:29.12 |
-31:30:27.8 |
HIP 87022 |
30.88 |
| 2026-06-02 00:00 |
17:44:18.12 |
-31:30:51.1 |
HIP 86617 |
31.57 |
| 2026-06-02 12:00 |
17:44:07.07 |
-31:31:14.1 |
HIP 86617 |
29.47 |
| 2026-06-03 00:00 |
17:43:56.00 |
-31:31:36.8 |
HIP 86617 |
27.40 |
| 2026-06-03 12:00 |
17:43:44.88 |
-31:31:59.2 |
HIP 86617 |
25.39 |
| 2026-06-04 00:00 |
17:43:33.73 |
-31:32:21.3 |
HIP 86617 |
23.44 |
| 2026-06-04 12:00 |
17:43:22.55 |
-31:32:43.1 |
HIP 86617 |
21.58 |
| 2026-06-05 00:00 |
17:43:11.33 |
-31:33:04.6 |
HIP 86617 |
19.83 |
| 2026-06-05 12:00 |
17:43:00.08 |
-31:33:25.8 |
HIP 86617 |
18.22 |
| 2026-06-06 00:00 |
17:42:48.81 |
-31:33:46.7 |
HIP 86617 |
16.80 |
| 2026-06-06 12:00 |
17:42:37.50 |
-31:34:07.2 |
HIP 86617 |
15.62 |
| 2026-06-07 00:00 |
17:42:26.17 |
-31:34:27.5 |
HIP 86617 |
14.75 |
| 2026-06-07 12:00 |
17:42:14.82 |
-31:34:47.5 |
HIP 86617 |
14.24 |
| 2026-06-08 00:00 |
17:42:03.43 |
-31:35:07.1 |
HIP 86617 |
14.14 |
| 2026-06-08 12:00 |
17:41:52.03 |
-31:35:26.5 |
HIP 86512 |
13.85 |
| 2026-06-09 00:00 |
17:41:40.60 |
-31:35:45.5 |
HIP 86512 |
11.56 |
| 2026-06-09 12:00 |
17:41:29.16 |
-31:36:04.2 |
HIP 86512 |
9.36 |
| 2026-06-10 00:00 |
17:41:17.69 |
-31:36:22.6 |
HIP 86512 |
7.32 |
| 2026-06-10 12:00 |
17:41:06.21 |
-31:36:40.7 |
HIP 86512 |
5.61 |
| 2026-06-11 00:00 |
17:40:54.72 |
-31:36:58.5 |
HIP 86512 |
4.64 |
| 2026-06-11 12:00 |
17:40:43.20 |
-31:37:16.0 |
HIP 86512 |
4.87 |
| 2026-06-12 00:00 |
17:40:31.68 |
-31:37:33.1 |
HIP 86512 |
6.17 |
| 2026-06-12 12:00 |
17:40:20.14 |
-31:37:50.0 |
HIP 86512 |
8.03 |
| 2026-06-13 00:00 |
17:40:08.60 |
-31:38:06.5 |
HIP 86512 |
10.16 |
| 2026-06-13 12:00 |
17:39:57.04 |
-31:38:22.7 |
HIP 86512 |
12.42 |
| 2026-06-14 00:00 |
17:39:45.48 |
-31:38:38.6 |
HIP 86512 |
14.74 |
| 2026-06-14 12:00 |
17:39:33.91 |
-31:38:54.2 |
HIP 86512 |
17.11 |
| 2026-06-15 00:00 |
17:39:22.34 |
-31:39:09.4 |
HIP 86512 |
19.50 |
| 2026-06-15 12:00 |
17:39:10.77 |
-31:39:24.4 |
HIP 86512 |
21.91 |
| 2026-06-16 00:00 |
17:38:59.20 |
-31:39:39.0 |
HIP 86512 |
24.33 |
| 2026-06-16 12:00 |
17:38:47.62 |
-31:39:53.4 |
HIP 86223 |
26.14 |
| 2026-06-17 00:00 |
17:38:36.05 |
-31:40:07.4 |
HIP 86223 |
24.46 |
| 2026-06-17 12:00 |
17:38:24.48 |
-31:40:21.1 |
HIP 86223 |
22.92 |
| 2026-06-18 00:00 |
17:38:12.92 |
-31:40:34.5 |
HIP 86223 |
21.55 |
| 2026-06-18 12:00 |
17:38:01.37 |
-31:40:47.5 |
HIP 86223 |
20.39 |
| 2026-06-19 00:00 |
17:37:49.82 |
-31:41:00.3 |
HIP 86223 |
19.47 |
| 2026-06-19 12:00 |
17:37:38.28 |
-31:41:12.7 |
HIP 86223 |
18.83 |
| 2026-06-20 00:00 |
17:37:26.76 |
-31:41:24.9 |
HIP 86223 |
18.49 |
| 2026-06-20 12:00 |
17:37:15.24 |
-31:41:36.7 |
HIP 86223 |
18.47 |
| 2026-06-21 00:00 |
17:37:03.74 |
-31:41:48.2 |
HIP 86223 |
18.77 |
| 2026-06-21 12:00 |
17:36:52.26 |
-31:41:59.4 |
HIP 86223 |
19.37 |
| 2026-06-22 00:00 |
17:36:40.79 |
-31:42:10.3 |
HIP 86223 |
20.25 |