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 |
-0.569 |
| 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) |
| 2026-03-26 00:00 |
17:56:16.14 |
-30:09:20.1 |
HIP 87760 |
13.64 |
| 2026-03-26 12:00 |
17:56:18.42 |
-30:10:00.8 |
HIP 87760 |
14.48 |
| 2026-03-27 00:00 |
17:56:20.58 |
-30:10:41.6 |
HIP 87760 |
15.30 |
| 2026-03-27 12:00 |
17:56:22.61 |
-30:11:22.4 |
HIP 87760 |
16.11 |
| 2026-03-28 00:00 |
17:56:24.53 |
-30:12:03.2 |
HIP 87760 |
16.90 |
| 2026-03-28 12:00 |
17:56:26.32 |
-30:12:44.1 |
HIP 87760 |
17.67 |
| 2026-03-29 00:00 |
17:56:27.99 |
-30:13:24.9 |
HIP 87760 |
18.44 |
| 2026-03-29 12:00 |
17:56:29.54 |
-30:14:05.8 |
HIP 87760 |
19.18 |
| 2026-03-30 00:00 |
17:56:30.97 |
-30:14:46.7 |
HIP 87760 |
19.91 |
| 2026-03-30 12:00 |
17:56:32.28 |
-30:15:27.6 |
HIP 87760 |
20.63 |
| 2026-03-31 00:00 |
17:56:33.47 |
-30:16:08.5 |
HIP 87956 |
21.34 |
| 2026-03-31 12:00 |
17:56:34.53 |
-30:16:49.5 |
HIP 87956 |
20.87 |
| 2026-04-01 00:00 |
17:56:35.47 |
-30:17:30.4 |
HIP 87956 |
20.45 |
| 2026-04-01 12:00 |
17:56:36.29 |
-30:18:11.4 |
HIP 87956 |
20.06 |
| 2026-04-02 00:00 |
17:56:36.99 |
-30:18:52.3 |
HIP 87956 |
19.72 |
| 2026-04-02 12:00 |
17:56:37.57 |
-30:19:33.3 |
HIP 87956 |
19.42 |
| 2026-04-03 00:00 |
17:56:38.02 |
-30:20:14.3 |
HIP 87956 |
19.17 |
| 2026-04-03 12:00 |
17:56:38.36 |
-30:20:55.3 |
HIP 87956 |
18.97 |
| 2026-04-04 00:00 |
17:56:38.57 |
-30:21:36.3 |
HIP 87956 |
18.82 |
| 2026-04-04 12:00 |
17:56:38.66 |
-30:22:17.3 |
HIP 87956 |
18.72 |
| 2026-04-05 00:00 |
17:56:38.62 |
-30:22:58.3 |
HIP 87956 |
18.66 |
| 2026-04-05 12:00 |
17:56:38.47 |
-30:23:39.2 |
HIP 87956 |
18.66 |
| 2026-04-06 00:00 |
17:56:38.19 |
-30:24:20.2 |
HIP 87956 |
18.71 |
| 2026-04-06 12:00 |
17:56:37.79 |
-30:25:01.2 |
HIP 87956 |
18.81 |
| 2026-04-07 00:00 |
17:56:37.27 |
-30:25:42.1 |
HIP 87956 |
18.97 |
| 2026-04-07 12:00 |
17:56:36.62 |
-30:26:23.1 |
HIP 87956 |
19.17 |
| 2026-04-08 00:00 |
17:56:35.85 |
-30:27:04.0 |
HIP 87756 |
19.36 |
| 2026-04-08 12:00 |
17:56:34.97 |
-30:27:44.9 |
HIP 87756 |
18.74 |
| 2026-04-09 00:00 |
17:56:33.95 |
-30:28:25.9 |
HIP 87756 |
18.10 |
| 2026-04-09 12:00 |
17:56:32.82 |
-30:29:06.7 |
HIP 87756 |
17.46 |
| 2026-04-10 00:00 |
17:56:31.56 |
-30:29:47.6 |
HIP 87756 |
16.80 |
| 2026-04-10 12:00 |
17:56:30.19 |
-30:30:28.4 |
HIP 87756 |
16.12 |
| 2026-04-11 00:00 |
17:56:28.69 |
-30:31:09.2 |
HIP 87756 |
15.44 |
| 2026-04-11 12:00 |
17:56:27.06 |
-30:31:50.0 |
HIP 87756 |
14.74 |
| 2026-04-12 00:00 |
17:56:25.32 |
-30:32:30.8 |
HIP 87756 |
14.02 |
| 2026-04-12 12:00 |
17:56:23.46 |
-30:33:11.5 |
HIP 87756 |
13.30 |
| 2026-04-13 00:00 |
17:56:21.47 |
-30:33:52.2 |
HIP 87756 |
12.56 |
| 2026-04-13 12:00 |
17:56:19.36 |
-30:34:32.8 |
HIP 87756 |
11.80 |
| 2026-04-14 00:00 |
17:56:17.13 |
-30:35:13.4 |
HIP 87756 |
11.03 |
| 2026-04-14 12:00 |
17:56:14.78 |
-30:35:54.0 |
HIP 87756 |
10.25 |
| 2026-04-15 00:00 |
17:56:12.31 |
-30:36:34.5 |
HIP 87756 |
9.46 |
| 2026-04-15 12:00 |
17:56:09.71 |
-30:37:15.0 |
HIP 87756 |
8.66 |
| 2026-04-16 00:00 |
17:56:07.00 |
-30:37:55.4 |
HIP 87756 |
7.85 |