メタデータ
| 項目 |
値 |
| Designation |
C/2021 X2 (Bok) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-07-08T03:45:12.778560Z |
| Orbit solution date (soln_date, UTC) |
2024-04-15T15:43:28Z |
| Obs used |
95 |
| NEO |
- |
| M1 |
10.600 |
| K1 |
16.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-12-01T09:04:17.558400Z |
| Discovery magnitude (MPC) |
21.60 G |
| Discovery observatory (MPC) |
V00 · Kitt Peak-Bok |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2022-06-25.0000000 |
| e |
1.00130749 |
| q (au) |
2.994542 |
| a (au) |
-2290.292591 |
| i (deg) |
137.143974 |
| Ω (om, deg) |
228.798155 |
| ω (w, deg) |
193.283930 |
| M (ma, deg) |
-0.000118 |
等級
散乱 + 全体線形
$$
M_a = (10.258 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.258 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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) |
| 2026-06-01 00:00 |
17:57:03.76 |
-56:08:06.1 |
HIP 87753 |
16.32 |
| 2026-06-01 12:00 |
17:56:41.87 |
-56:08:13.8 |
HIP 87753 |
13.92 |
| 2026-06-02 00:00 |
17:56:19.92 |
-56:08:20.6 |
HIP 87753 |
11.82 |
| 2026-06-02 12:00 |
17:55:57.93 |
-56:08:26.5 |
HIP 87753 |
10.24 |
| 2026-06-03 00:00 |
17:55:35.89 |
-56:08:31.4 |
HIP 87753 |
9.42 |
| 2026-06-03 12:00 |
17:55:13.80 |
-56:08:35.4 |
HIP 87753 |
9.58 |
| 2026-06-04 00:00 |
17:54:51.67 |
-56:08:38.4 |
HIP 87753 |
10.68 |
| 2026-06-04 12:00 |
17:54:29.50 |
-56:08:40.5 |
HIP 87753 |
12.48 |
| 2026-06-05 00:00 |
17:54:07.29 |
-56:08:41.6 |
HIP 87522 |
10.51 |
| 2026-06-05 12:00 |
17:53:45.04 |
-56:08:41.7 |
HIP 87522 |
7.42 |
| 2026-06-06 00:00 |
17:53:22.76 |
-56:08:40.8 |
HIP 87522 |
4.34 |
| 2026-06-06 12:00 |
17:53:00.44 |
-56:08:39.0 |
HIP 87522 |
1.35 |
| 2026-06-07 00:00 |
17:52:38.09 |
-56:08:36.3 |
HIP 87522 |
2.04 |
| 2026-06-07 12:00 |
17:52:15.71 |
-56:08:32.5 |
HIP 87522 |
5.09 |
| 2026-06-08 00:00 |
17:51:53.31 |
-56:08:27.8 |
HIP 87522 |
8.20 |
| 2026-06-08 12:00 |
17:51:30.88 |
-56:08:22.1 |
HIP 87522 |
11.32 |
| 2026-06-09 00:00 |
17:51:08.42 |
-56:08:15.4 |
HIP 87522 |
14.45 |
| 2026-06-09 12:00 |
17:50:45.95 |
-56:08:07.8 |
HIP 87522 |
17.58 |
| 2026-06-10 00:00 |
17:50:23.46 |
-56:07:59.1 |
HIP 87522 |
20.72 |
| 2026-06-10 12:00 |
17:50:00.95 |
-56:07:49.5 |
HIP 87070 |
20.74 |
| 2026-06-11 00:00 |
17:49:38.43 |
-56:07:38.9 |
HIP 87070 |
17.64 |
| 2026-06-11 12:00 |
17:49:15.89 |
-56:07:27.3 |
HIP 87070 |
14.57 |
| 2026-06-12 00:00 |
17:48:53.35 |
-56:07:14.7 |
HIP 87070 |
11.54 |
| 2026-06-12 12:00 |
17:48:30.80 |
-56:07:01.1 |
HIP 87070 |
8.59 |
| 2026-06-13 00:00 |
17:48:08.24 |
-56:06:46.6 |
HIP 87070 |
5.87 |
| 2026-06-13 12:00 |
17:47:45.68 |
-56:06:31.1 |
HIP 87070 |
3.88 |
| 2026-06-14 00:00 |
17:47:23.13 |
-56:06:14.5 |
HIP 87070 |
3.95 |
| 2026-06-14 12:00 |
17:47:00.57 |
-56:05:57.0 |
HIP 87070 |
6.02 |
| 2026-06-15 00:00 |
17:46:38.02 |
-56:05:38.5 |
HIP 87070 |
8.77 |
| 2026-06-15 12:00 |
17:46:15.47 |
-56:05:19.0 |
HIP 87070 |
11.74 |
| 2026-06-16 00:00 |
17:45:52.93 |
-56:04:58.6 |
HIP 87070 |
14.79 |
| 2026-06-16 12:00 |
17:45:30.41 |
-56:04:37.1 |
HIP 86978 |
17.67 |
| 2026-06-17 00:00 |
17:45:07.90 |
-56:04:14.7 |
HIP 86978 |
19.03 |
| 2026-06-17 12:00 |
17:44:45.40 |
-56:03:51.2 |
HIP 86780 |
18.70 |
| 2026-06-18 00:00 |
17:44:22.93 |
-56:03:26.8 |
HIP 86780 |
18.23 |
| 2026-06-18 12:00 |
17:44:00.47 |
-56:03:01.5 |
HIP 86640 |
16.52 |
| 2026-06-19 00:00 |
17:43:38.04 |
-56:02:35.1 |
HIP 86640 |
13.51 |
| 2026-06-19 12:00 |
17:43:15.63 |
-56:02:07.8 |
HIP 86640 |
10.58 |
| 2026-06-20 00:00 |
17:42:53.25 |
-56:01:39.5 |
HIP 86640 |
7.83 |
| 2026-06-20 12:00 |
17:42:30.89 |
-56:01:10.3 |
HIP 86640 |
5.52 |
| 2026-06-21 00:00 |
17:42:08.57 |
-56:00:40.0 |
HIP 86640 |
4.42 |
| 2026-06-21 12:00 |
17:41:46.29 |
-56:00:08.9 |
HIP 86640 |
5.34 |
| 2026-06-22 00:00 |
17:41:24.04 |
-55:59:36.7 |
HIP 86640 |
7.57 |