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) |
| 2026-07-29 00:00 |
17:24:46.66 |
-31:43:34.9 |
HIP 85100 |
15.82 |
| 2026-07-29 12:00 |
17:24:39.88 |
-31:43:28.8 |
HIP 85100 |
14.37 |
| 2026-07-30 00:00 |
17:24:33.19 |
-31:43:22.5 |
HIP 85100 |
12.94 |
| 2026-07-30 12:00 |
17:24:26.60 |
-31:43:16.1 |
HIP 85100 |
11.54 |
| 2026-07-31 00:00 |
17:24:20.11 |
-31:43:09.6 |
HIP 85100 |
10.16 |
| 2026-07-31 12:00 |
17:24:13.72 |
-31:43:03.0 |
HIP 85100 |
8.79 |
| 2026-08-01 00:00 |
17:24:07.44 |
-31:42:56.3 |
HIP 85100 |
7.45 |
| 2026-08-01 12:00 |
17:24:01.25 |
-31:42:49.5 |
HIP 85100 |
6.13 |
| 2026-08-02 00:00 |
17:23:55.16 |
-31:42:42.6 |
HIP 85100 |
4.84 |
| 2026-08-02 12:00 |
17:23:49.18 |
-31:42:35.6 |
HIP 85100 |
3.56 |
| 2026-08-03 00:00 |
17:23:43.30 |
-31:42:28.5 |
HIP 85100 |
2.31 |
| 2026-08-03 12:00 |
17:23:37.53 |
-31:42:21.3 |
HIP 85100 |
1.09 |
| 2026-08-04 00:00 |
17:23:31.86 |
-31:42:14.1 |
HIP 85100 |
0.27 |
| 2026-08-04 12:00 |
17:23:26.29 |
-31:42:06.7 |
HIP 85100 |
1.36 |
| 2026-08-05 00:00 |
17:23:20.83 |
-31:41:59.3 |
HIP 85100 |
2.52 |
| 2026-08-05 12:00 |
17:23:15.47 |
-31:41:51.8 |
HIP 85100 |
3.66 |
| 2026-08-06 00:00 |
17:23:10.22 |
-31:41:44.2 |
HIP 85100 |
4.78 |
| 2026-08-06 12:00 |
17:23:05.08 |
-31:41:36.6 |
HIP 85100 |
5.88 |
| 2026-08-07 00:00 |
17:23:00.04 |
-31:41:28.8 |
HIP 85100 |
6.96 |
| 2026-08-07 12:00 |
17:22:55.11 |
-31:41:21.1 |
HIP 85100 |
8.01 |
| 2026-08-08 00:00 |
17:22:50.29 |
-31:41:13.2 |
HIP 84987 |
8.02 |
| 2026-08-08 12:00 |
17:22:45.58 |
-31:41:05.3 |
HIP 84987 |
7.01 |
| 2026-08-09 00:00 |
17:22:40.98 |
-31:40:57.4 |
HIP 84987 |
6.03 |
| 2026-08-09 12:00 |
17:22:36.49 |
-31:40:49.4 |
HIP 84987 |
5.07 |
| 2026-08-10 00:00 |
17:22:32.11 |
-31:40:41.3 |
HIP 84987 |
4.14 |
| 2026-08-10 12:00 |
17:22:27.84 |
-31:40:33.3 |
HIP 84987 |
3.23 |
| 2026-08-11 00:00 |
17:22:23.68 |
-31:40:25.1 |
HIP 84987 |
2.36 |
| 2026-08-11 12:00 |
17:22:19.63 |
-31:40:17.0 |
HIP 84987 |
1.53 |
| 2026-08-12 00:00 |
17:22:15.70 |
-31:40:08.8 |
HIP 84987 |
0.82 |
| 2026-08-12 12:00 |
17:22:11.88 |
-31:40:00.5 |
HIP 84987 |
0.64 |
| 2026-08-13 00:00 |
17:22:08.17 |
-31:39:52.2 |
HIP 84987 |
1.21 |
| 2026-08-13 12:00 |
17:22:04.57 |
-31:39:44.0 |
HIP 84987 |
1.92 |
| 2026-08-14 00:00 |
17:22:01.09 |
-31:39:35.6 |
HIP 84987 |
2.65 |
| 2026-08-14 12:00 |
17:21:57.72 |
-31:39:27.3 |
HIP 84987 |
3.36 |
| 2026-08-15 00:00 |
17:21:54.47 |
-31:39:18.9 |
HIP 84987 |
4.06 |
| 2026-08-15 12:00 |
17:21:51.33 |
-31:39:10.6 |
HIP 84987 |
4.73 |
| 2026-08-16 00:00 |
17:21:48.30 |
-31:39:02.2 |
HIP 84987 |
5.38 |
| 2026-08-16 12:00 |
17:21:45.39 |
-31:38:53.8 |
HIP 84987 |
6.01 |
| 2026-08-17 00:00 |
17:21:42.60 |
-31:38:45.4 |
HIP 84987 |
6.62 |
| 2026-08-17 12:00 |
17:21:39.92 |
-31:38:37.0 |
HIP 84987 |
7.20 |
| 2026-08-18 00:00 |
17:21:37.35 |
-31:38:28.6 |
HIP 84987 |
7.76 |
| 2026-08-18 12:00 |
17:21:34.90 |
-31:38:20.2 |
HIP 84987 |
8.30 |
| 2026-08-19 00:00 |
17:21:32.57 |
-31:38:11.8 |
HIP 84987 |
8.81 |