メタデータ
| 項目 |
値 |
| Designation |
C/2021 J2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-09-22T11:24:15.621120Z |
| Orbit solution date (soln_date, UTC) |
2023-12-06T01:14:09Z |
| Obs used |
218 |
| NEO |
- |
| M1 |
13.600 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-05-10T09:49:17.990400Z |
| Discovery magnitude (MPC) |
22.06 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) |
2022-02-01.0000000 |
| e |
0.95985091 |
| q (au) |
4.706567 |
| a (au) |
117.227257 |
| i (deg) |
156.209020 |
| Ω (om, deg) |
23.329370 |
| ω (w, deg) |
172.059356 |
| M (ma, deg) |
0.102134 |
等級
散乱 + 全体線形
$$
M_a = (14.688 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
14.688 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.612 |
| k |
0.800 |
| 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) |
| 2026-05-12 00:00 |
06:42:17.99 |
+00:31:30.4 |
HIP 31992 |
18.22 |
| 2026-05-12 12:00 |
06:42:21.84 |
+00:32:08.4 |
HIP 31992 |
19.25 |
| 2026-05-13 00:00 |
06:42:25.74 |
+00:32:46.0 |
HIP 31992 |
20.30 |
| 2026-05-13 12:00 |
06:42:29.70 |
+00:33:23.2 |
HIP 31992 |
21.38 |
| 2026-05-14 00:00 |
06:42:33.70 |
+00:34:00.0 |
HIP 31992 |
22.47 |
| 2026-05-14 12:00 |
06:42:37.76 |
+00:34:36.3 |
HIP 31992 |
23.59 |
| 2026-05-15 00:00 |
06:42:41.87 |
+00:35:12.2 |
HIP 31992 |
24.72 |
| 2026-05-15 12:00 |
06:42:46.03 |
+00:35:47.7 |
HIP 31992 |
25.87 |
| 2026-05-16 00:00 |
06:42:50.23 |
+00:36:22.9 |
HIP 32300 |
26.60 |
| 2026-05-16 12:00 |
06:42:54.49 |
+00:36:57.6 |
HIP 32300 |
25.57 |
| 2026-05-17 00:00 |
06:42:58.79 |
+00:37:31.8 |
HIP 32300 |
24.54 |
| 2026-05-17 12:00 |
06:43:03.15 |
+00:38:05.7 |
HIP 32300 |
23.51 |
| 2026-05-18 00:00 |
06:43:07.55 |
+00:38:39.2 |
HIP 32300 |
22.49 |
| 2026-05-18 12:00 |
06:43:11.99 |
+00:39:12.2 |
HIP 32300 |
21.49 |
| 2026-05-19 00:00 |
06:43:16.48 |
+00:39:44.8 |
HIP 32300 |
20.49 |
| 2026-05-19 12:00 |
06:43:21.02 |
+00:40:17.0 |
HIP 32300 |
19.51 |
| 2026-05-20 00:00 |
06:43:25.60 |
+00:40:48.8 |
HIP 32300 |
18.56 |
| 2026-05-20 12:00 |
06:43:30.23 |
+00:41:20.1 |
HIP 32300 |
17.62 |
| 2026-05-21 00:00 |
06:43:34.90 |
+00:41:51.0 |
HIP 32300 |
16.72 |
| 2026-05-21 12:00 |
06:43:39.62 |
+00:42:21.5 |
HIP 32300 |
15.86 |
| 2026-05-22 00:00 |
06:43:44.37 |
+00:42:51.6 |
HIP 32300 |
15.05 |
| 2026-05-22 12:00 |
06:43:49.17 |
+00:43:21.3 |
HIP 32300 |
14.29 |
| 2026-05-23 00:00 |
06:43:54.01 |
+00:43:50.5 |
HIP 32300 |
13.60 |
| 2026-05-23 12:00 |
06:43:58.90 |
+00:44:19.3 |
HIP 32300 |
13.00 |
| 2026-05-24 00:00 |
06:44:03.82 |
+00:44:47.7 |
HIP 32300 |
12.49 |
| 2026-05-24 12:00 |
06:44:08.78 |
+00:45:15.6 |
HIP 32300 |
12.09 |
| 2026-05-25 00:00 |
06:44:13.78 |
+00:45:43.2 |
HIP 32300 |
11.82 |
| 2026-05-25 12:00 |
06:44:18.82 |
+00:46:10.3 |
HIP 32300 |
11.69 |
| 2026-05-26 00:00 |
06:44:23.90 |
+00:46:37.0 |
HIP 32300 |
11.69 |
| 2026-05-26 12:00 |
06:44:29.02 |
+00:47:03.2 |
HIP 32327 |
11.63 |
| 2026-05-27 00:00 |
06:44:34.17 |
+00:47:29.0 |
HIP 32327 |
11.39 |
| 2026-05-27 12:00 |
06:44:39.36 |
+00:47:54.4 |
HIP 32327 |
11.29 |
| 2026-05-28 00:00 |
06:44:44.59 |
+00:48:19.4 |
HIP 32327 |
11.35 |
| 2026-05-28 12:00 |
06:44:49.85 |
+00:48:44.0 |
HIP 32327 |
11.57 |
| 2026-05-29 00:00 |
06:44:55.14 |
+00:49:08.1 |
HIP 32327 |
11.93 |
| 2026-05-29 12:00 |
06:45:00.48 |
+00:49:31.8 |
HIP 32327 |
12.43 |
| 2026-05-30 00:00 |
06:45:05.84 |
+00:49:55.1 |
HIP 32327 |
13.06 |
| 2026-05-30 12:00 |
06:45:11.24 |
+00:50:17.9 |
HIP 32327 |
13.79 |
| 2026-05-31 00:00 |
06:45:16.67 |
+00:50:40.3 |
HIP 32327 |
14.63 |
| 2026-05-31 12:00 |
06:45:22.14 |
+00:51:02.3 |
HIP 32327 |
15.54 |
| 2026-06-01 00:00 |
06:45:27.64 |
+00:51:23.9 |
HIP 32327 |
16.52 |
| 2026-06-01 12:00 |
06:45:33.17 |
+00:51:45.0 |
HIP 32327 |
17.56 |
| 2026-06-02 00:00 |
06:45:38.73 |
+00:52:05.7 |
HIP 32327 |
18.65 |