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) |
| 2026-07-29 00:00 |
06:57:26.53 |
+00:45:49.8 |
HIP 33525 |
25.42 |
| 2026-07-29 12:00 |
06:57:32.25 |
+00:45:24.2 |
HIP 33525 |
24.53 |
| 2026-07-30 00:00 |
06:57:37.94 |
+00:44:58.4 |
HIP 33525 |
23.70 |
| 2026-07-30 12:00 |
06:57:43.60 |
+00:44:32.2 |
HIP 33525 |
22.93 |
| 2026-07-31 00:00 |
06:57:49.23 |
+00:44:05.6 |
HIP 33525 |
22.23 |
| 2026-07-31 12:00 |
06:57:54.84 |
+00:43:38.8 |
HIP 33525 |
21.59 |
| 2026-08-01 00:00 |
06:58:00.41 |
+00:43:11.6 |
HIP 33525 |
21.04 |
| 2026-08-01 12:00 |
06:58:05.96 |
+00:42:44.1 |
HIP 33525 |
20.58 |
| 2026-08-02 00:00 |
06:58:11.47 |
+00:42:16.2 |
HIP 33525 |
20.20 |
| 2026-08-02 12:00 |
06:58:16.96 |
+00:41:48.0 |
HIP 33525 |
19.91 |
| 2026-08-03 00:00 |
06:58:22.41 |
+00:41:19.5 |
HIP 33525 |
19.72 |
| 2026-08-03 12:00 |
06:58:27.83 |
+00:40:50.7 |
HIP 33525 |
19.63 |
| 2026-08-04 00:00 |
06:58:33.22 |
+00:40:21.6 |
HIP 33525 |
19.63 |
| 2026-08-04 12:00 |
06:58:38.57 |
+00:39:52.1 |
HIP 33525 |
19.73 |
| 2026-08-05 00:00 |
06:58:43.90 |
+00:39:22.3 |
HIP 33657 |
19.69 |
| 2026-08-05 12:00 |
06:58:49.19 |
+00:38:52.2 |
HIP 33657 |
19.33 |
| 2026-08-06 00:00 |
06:58:54.44 |
+00:38:21.8 |
HIP 33657 |
19.08 |
| 2026-08-06 12:00 |
06:58:59.67 |
+00:37:51.0 |
HIP 33657 |
18.94 |
| 2026-08-07 00:00 |
06:59:04.85 |
+00:37:20.0 |
HIP 33657 |
18.91 |
| 2026-08-07 12:00 |
06:59:10.00 |
+00:36:48.7 |
HIP 33657 |
18.99 |
| 2026-08-08 00:00 |
06:59:15.12 |
+00:36:17.0 |
HIP 33657 |
19.18 |
| 2026-08-08 12:00 |
06:59:20.20 |
+00:35:45.0 |
HIP 33657 |
19.47 |
| 2026-08-09 00:00 |
06:59:25.24 |
+00:35:12.8 |
HIP 33677 |
19.30 |
| 2026-08-09 12:00 |
06:59:30.24 |
+00:34:40.2 |
HIP 33677 |
18.46 |
| 2026-08-10 00:00 |
06:59:35.21 |
+00:34:07.3 |
HIP 33677 |
17.67 |
| 2026-08-10 12:00 |
06:59:40.13 |
+00:33:34.1 |
HIP 33677 |
16.96 |
| 2026-08-11 00:00 |
06:59:45.02 |
+00:33:00.7 |
HIP 33677 |
16.32 |
| 2026-08-11 12:00 |
06:59:49.87 |
+00:32:26.9 |
HIP 33677 |
15.76 |
| 2026-08-12 00:00 |
06:59:54.68 |
+00:31:52.8 |
HIP 33677 |
15.30 |
| 2026-08-12 12:00 |
06:59:59.44 |
+00:31:18.5 |
HIP 33677 |
14.93 |
| 2026-08-13 00:00 |
07:00:04.17 |
+00:30:43.9 |
HIP 33677 |
14.66 |
| 2026-08-13 12:00 |
07:00:08.85 |
+00:30:08.9 |
HIP 33677 |
14.51 |
| 2026-08-14 00:00 |
07:00:13.50 |
+00:29:33.7 |
HIP 33677 |
14.45 |
| 2026-08-14 12:00 |
07:00:18.10 |
+00:28:58.3 |
HIP 33677 |
14.51 |
| 2026-08-15 00:00 |
07:00:22.65 |
+00:28:22.5 |
HIP 33677 |
14.67 |
| 2026-08-15 12:00 |
07:00:27.17 |
+00:27:46.5 |
HIP 33677 |
14.93 |
| 2026-08-16 00:00 |
07:00:31.63 |
+00:27:10.2 |
HIP 33677 |
15.28 |
| 2026-08-16 12:00 |
07:00:36.06 |
+00:26:33.6 |
HIP 33677 |
15.71 |
| 2026-08-17 00:00 |
07:00:40.44 |
+00:25:56.8 |
HIP 33677 |
16.22 |
| 2026-08-17 12:00 |
07:00:44.77 |
+00:25:19.7 |
HIP 33677 |
16.80 |
| 2026-08-18 00:00 |
07:00:49.06 |
+00:24:42.3 |
HIP 33677 |
17.43 |
| 2026-08-18 12:00 |
07:00:53.30 |
+00:24:04.7 |
HIP 33677 |
18.12 |
| 2026-08-19 00:00 |
07:00:57.49 |
+00:23:26.8 |
HIP 33677 |
18.84 |