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) |
| 2026-09-20 00:00 |
17:23:03.15 |
-31:30:59.2 |
HIP 85100 |
12.70 |
| 2026-09-20 12:00 |
17:23:08.22 |
-31:30:55.2 |
HIP 85100 |
12.26 |
| 2026-09-21 00:00 |
17:23:13.41 |
-31:30:51.4 |
HIP 85100 |
11.89 |
| 2026-09-21 12:00 |
17:23:18.70 |
-31:30:47.7 |
HIP 85100 |
11.61 |
| 2026-09-22 00:00 |
17:23:24.10 |
-31:30:44.0 |
HIP 85100 |
11.43 |
| 2026-09-22 12:00 |
17:23:29.60 |
-31:30:40.5 |
HIP 85100 |
11.36 |
| 2026-09-23 00:00 |
17:23:35.20 |
-31:30:37.1 |
HIP 85100 |
11.41 |
| 2026-09-23 12:00 |
17:23:40.92 |
-31:30:33.8 |
HIP 85100 |
11.59 |
| 2026-09-24 00:00 |
17:23:46.73 |
-31:30:30.6 |
HIP 85100 |
11.89 |
| 2026-09-24 12:00 |
17:23:52.65 |
-31:30:27.6 |
HIP 85100 |
12.32 |
| 2026-09-25 00:00 |
17:23:58.67 |
-31:30:24.6 |
HIP 85100 |
12.86 |
| 2026-09-25 12:00 |
17:24:04.80 |
-31:30:21.8 |
HIP 85100 |
13.52 |
| 2026-09-26 00:00 |
17:24:11.03 |
-31:30:19.1 |
HIP 85100 |
14.27 |
| 2026-09-26 12:00 |
17:24:17.36 |
-31:30:16.5 |
HIP 85100 |
15.12 |
| 2026-09-27 00:00 |
17:24:23.79 |
-31:30:14.0 |
HIP 85100 |
16.04 |
| 2026-09-27 12:00 |
17:24:30.32 |
-31:30:11.6 |
HIP 85100 |
17.05 |
| 2026-09-28 00:00 |
17:24:36.95 |
-31:30:09.4 |
HIP 85100 |
18.12 |
| 2026-09-28 12:00 |
17:24:43.69 |
-31:30:07.2 |
HIP 85100 |
19.24 |
| 2026-09-29 00:00 |
17:24:50.52 |
-31:30:05.2 |
HIP 85329 |
20.02 |
| 2026-09-29 12:00 |
17:24:57.46 |
-31:30:03.3 |
HIP 85329 |
18.71 |
| 2026-09-30 00:00 |
17:25:04.49 |
-31:30:01.5 |
HIP 85329 |
17.40 |
| 2026-09-30 12:00 |
17:25:11.62 |
-31:29:59.8 |
HIP 85329 |
16.10 |
| 2026-10-01 00:00 |
17:25:18.85 |
-31:29:58.3 |
HIP 85329 |
14.83 |
| 2026-10-01 12:00 |
17:25:26.18 |
-31:29:56.9 |
HIP 85329 |
13.60 |
| 2026-10-02 00:00 |
17:25:33.60 |
-31:29:55.6 |
HIP 85329 |
12.43 |
| 2026-10-02 12:00 |
17:25:41.13 |
-31:29:54.4 |
HIP 85329 |
11.34 |
| 2026-10-03 00:00 |
17:25:48.75 |
-31:29:53.3 |
HIP 85329 |
10.37 |
| 2026-10-03 12:00 |
17:25:56.47 |
-31:29:52.3 |
HIP 85329 |
9.57 |
| 2026-10-04 00:00 |
17:26:04.28 |
-31:29:51.5 |
HIP 85329 |
8.99 |
| 2026-10-04 12:00 |
17:26:12.19 |
-31:29:50.8 |
HIP 85329 |
8.70 |
| 2026-10-05 00:00 |
17:26:20.19 |
-31:29:50.2 |
HIP 85329 |
8.73 |
| 2026-10-05 12:00 |
17:26:28.29 |
-31:29:49.7 |
HIP 85329 |
9.08 |
| 2026-10-06 00:00 |
17:26:36.49 |
-31:29:49.3 |
HIP 85329 |
9.74 |
| 2026-10-06 12:00 |
17:26:44.78 |
-31:29:49.1 |
HIP 85329 |
10.66 |
| 2026-10-07 00:00 |
17:26:53.16 |
-31:29:49.0 |
HIP 85329 |
11.79 |
| 2026-10-07 12:00 |
17:27:01.63 |
-31:29:49.0 |
HIP 85329 |
13.07 |
| 2026-10-08 00:00 |
17:27:10.20 |
-31:29:49.1 |
HIP 85329 |
14.49 |
| 2026-10-08 12:00 |
17:27:18.86 |
-31:29:49.3 |
HIP 85329 |
16.00 |
| 2026-10-09 00:00 |
17:27:27.62 |
-31:29:49.7 |
HIP 85524 |
17.03 |
| 2026-10-09 12:00 |
17:27:36.46 |
-31:29:50.1 |
HIP 85524 |
15.32 |
| 2026-10-10 00:00 |
17:27:45.39 |
-31:29:50.7 |
HIP 85524 |
13.64 |
| 2026-10-10 12:00 |
17:27:54.42 |
-31:29:51.5 |
HIP 85524 |
12.02 |
| 2026-10-11 00:00 |
17:28:03.53 |
-31:29:52.3 |
HIP 85524 |
10.48 |