P/2021 C2 (PANSTARRS)
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) |
| 2026-02-03 00:00 |
17:42:47.91 |
-29:04:04.8 |
HIP 86619 |
11.02 |
| 2026-02-03 12:00 |
17:43:00.54 |
-29:04:40.9 |
HIP 86619 |
13.71 |
| 2026-02-04 00:00 |
17:43:13.10 |
-29:05:17.0 |
HIP 86619 |
16.43 |
| 2026-02-04 12:00 |
17:43:25.59 |
-29:05:53.2 |
HIP 86619 |
19.15 |
| 2026-02-05 00:00 |
17:43:38.00 |
-29:06:29.4 |
HIP 86619 |
21.88 |
| 2026-02-05 12:00 |
17:43:50.34 |
-29:07:05.7 |
HIP 86911 |
21.77 |
| 2026-02-06 00:00 |
17:44:02.59 |
-29:07:41.9 |
HIP 86911 |
19.10 |
| 2026-02-06 12:00 |
17:44:14.78 |
-29:08:18.2 |
HIP 86911 |
16.47 |
| 2026-02-07 00:00 |
17:44:26.88 |
-29:08:54.6 |
HIP 86911 |
13.91 |
| 2026-02-07 12:00 |
17:44:38.91 |
-29:09:31.0 |
HIP 86911 |
11.42 |
| 2026-02-08 00:00 |
17:44:50.86 |
-29:10:07.4 |
HIP 86911 |
9.08 |
| 2026-02-08 12:00 |
17:45:02.73 |
-29:10:43.8 |
HIP 86911 |
6.99 |
| 2026-02-09 00:00 |
17:45:14.52 |
-29:11:20.3 |
HIP 86911 |
5.45 |
| 2026-02-09 12:00 |
17:45:26.22 |
-29:11:56.9 |
HIP 86911 |
4.95 |
| 2026-02-10 00:00 |
17:45:37.85 |
-29:12:33.4 |
HIP 86911 |
5.75 |
| 2026-02-10 12:00 |
17:45:49.39 |
-29:13:10.0 |
HIP 86911 |
7.42 |
| 2026-02-11 00:00 |
17:46:00.86 |
-29:13:46.7 |
HIP 86948 |
8.93 |
| 2026-02-11 12:00 |
17:46:12.24 |
-29:14:23.4 |
HIP 86948 |
9.85 |
| 2026-02-12 00:00 |
17:46:23.53 |
-29:15:00.1 |
HIP 87038 |
8.77 |
| 2026-02-12 12:00 |
17:46:34.74 |
-29:15:36.9 |
HIP 87038 |
6.36 |
| 2026-02-13 00:00 |
17:46:45.86 |
-29:16:13.7 |
HIP 87038 |
4.12 |
| 2026-02-13 12:00 |
17:46:56.90 |
-29:16:50.5 |
HIP 87038 |
2.45 |
| 2026-02-14 00:00 |
17:47:07.85 |
-29:17:27.4 |
HIP 87038 |
2.71 |
| 2026-02-14 12:00 |
17:47:18.72 |
-29:18:04.3 |
HIP 87038 |
4.55 |
| 2026-02-15 00:00 |
17:47:29.49 |
-29:18:41.3 |
HIP 87038 |
6.78 |
| 2026-02-15 12:00 |
17:47:40.18 |
-29:19:18.4 |
HIP 87038 |
9.09 |
| 2026-02-16 00:00 |
17:47:50.78 |
-29:19:55.4 |
HIP 87038 |
11.42 |
| 2026-02-16 12:00 |
17:48:01.29 |
-29:20:32.5 |
HIP 87038 |
13.76 |
| 2026-02-17 00:00 |
17:48:11.70 |
-29:21:09.7 |
HIP 87038 |
16.09 |
| 2026-02-17 12:00 |
17:48:22.03 |
-29:21:46.9 |
HIP 87233 |
14.69 |
| 2026-02-18 00:00 |
17:48:32.26 |
-29:22:24.2 |
HIP 87233 |
12.38 |
| 2026-02-18 12:00 |
17:48:42.40 |
-29:23:01.5 |
HIP 87233 |
10.09 |
| 2026-02-19 00:00 |
17:48:52.45 |
-29:23:38.8 |
HIP 87233 |
7.82 |
| 2026-02-19 12:00 |
17:49:02.41 |
-29:24:16.2 |
HIP 87233 |
5.57 |
| 2026-02-20 00:00 |
17:49:12.27 |
-29:24:53.7 |
HIP 87233 |
3.35 |
| 2026-02-20 12:00 |
17:49:22.03 |
-29:25:31.2 |
HIP 87233 |
1.20 |
| 2026-02-21 00:00 |
17:49:31.70 |
-29:26:08.7 |
HIP 87233 |
1.21 |
| 2026-02-21 12:00 |
17:49:41.28 |
-29:26:46.3 |
HIP 87233 |
3.32 |
| 2026-02-22 00:00 |
17:49:50.76 |
-29:27:24.0 |
HIP 87233 |
5.46 |
| 2026-02-22 12:00 |
17:50:00.14 |
-29:28:01.7 |
HIP 87233 |
7.59 |
| 2026-02-23 00:00 |
17:50:09.42 |
-29:28:39.4 |
HIP 87233 |
9.70 |
| 2026-02-23 12:00 |
17:50:18.60 |
-29:29:17.2 |
HIP 87233 |
11.79 |
| 2026-02-24 00:00 |
17:50:27.69 |
-29:29:55.1 |
HIP 87233 |
13.86 |