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) |
| 2026-03-26 00:00 |
18:27:54.20 |
-54:15:42.8 |
HIP 90470 |
13.88 |
| 2026-03-26 12:00 |
18:27:50.73 |
-54:16:49.8 |
HIP 90470 |
14.91 |
| 2026-03-27 00:00 |
18:27:47.10 |
-54:17:57.0 |
HIP 90470 |
15.97 |
| 2026-03-27 12:00 |
18:27:43.31 |
-54:19:04.2 |
HIP 90470 |
17.06 |
| 2026-03-28 00:00 |
18:27:39.36 |
-54:20:11.6 |
HIP 90470 |
18.17 |
| 2026-03-28 12:00 |
18:27:35.25 |
-54:21:19.0 |
HIP 90470 |
19.30 |
| 2026-03-29 00:00 |
18:27:30.97 |
-54:22:26.5 |
HIP 90470 |
20.44 |
| 2026-03-29 12:00 |
18:27:26.53 |
-54:23:34.1 |
HIP 90566 |
21.60 |
| 2026-03-30 00:00 |
18:27:21.92 |
-54:24:41.8 |
HIP 90566 |
21.07 |
| 2026-03-30 12:00 |
18:27:17.15 |
-54:25:49.6 |
HIP 90566 |
20.62 |
| 2026-03-31 00:00 |
18:27:12.22 |
-54:26:57.3 |
HIP 90566 |
20.26 |
| 2026-03-31 12:00 |
18:27:07.12 |
-54:28:05.2 |
HIP 90277 |
19.44 |
| 2026-04-01 00:00 |
18:27:01.86 |
-54:29:13.1 |
HIP 90277 |
18.20 |
| 2026-04-01 12:00 |
18:26:56.43 |
-54:30:21.0 |
HIP 90277 |
16.96 |
| 2026-04-02 00:00 |
18:26:50.84 |
-54:31:28.9 |
HIP 90277 |
15.72 |
| 2026-04-02 12:00 |
18:26:45.08 |
-54:32:36.9 |
HIP 90277 |
14.49 |
| 2026-04-03 00:00 |
18:26:39.16 |
-54:33:44.8 |
HIP 90277 |
13.27 |
| 2026-04-03 12:00 |
18:26:33.07 |
-54:34:52.8 |
HIP 90277 |
12.07 |
| 2026-04-04 00:00 |
18:26:26.82 |
-54:36:00.8 |
HIP 90277 |
10.91 |
| 2026-04-04 12:00 |
18:26:20.40 |
-54:37:08.8 |
HIP 90277 |
9.80 |
| 2026-04-05 00:00 |
18:26:13.81 |
-54:38:16.7 |
HIP 90277 |
8.77 |
| 2026-04-05 12:00 |
18:26:07.06 |
-54:39:24.6 |
HIP 90277 |
7.86 |
| 2026-04-06 00:00 |
18:26:00.14 |
-54:40:32.5 |
HIP 90277 |
7.14 |
| 2026-04-06 12:00 |
18:25:53.05 |
-54:41:40.4 |
HIP 90277 |
6.65 |
| 2026-04-07 00:00 |
18:25:45.80 |
-54:42:48.2 |
HIP 90277 |
6.49 |
| 2026-04-07 12:00 |
18:25:38.38 |
-54:43:55.9 |
HIP 90277 |
6.67 |
| 2026-04-08 00:00 |
18:25:30.79 |
-54:45:03.6 |
HIP 90277 |
7.18 |
| 2026-04-08 12:00 |
18:25:23.03 |
-54:46:11.2 |
HIP 90277 |
7.97 |
| 2026-04-09 00:00 |
18:25:15.11 |
-54:47:18.7 |
HIP 90277 |
8.97 |
| 2026-04-09 12:00 |
18:25:07.02 |
-54:48:26.1 |
HIP 90231 |
9.86 |
| 2026-04-10 00:00 |
18:24:58.76 |
-54:49:33.5 |
HIP 90231 |
8.38 |
| 2026-04-10 12:00 |
18:24:50.33 |
-54:50:40.7 |
HIP 90231 |
6.95 |
| 2026-04-11 00:00 |
18:24:41.73 |
-54:51:47.8 |
HIP 90231 |
5.65 |
| 2026-04-11 12:00 |
18:24:32.97 |
-54:52:54.8 |
HIP 90231 |
4.59 |
| 2026-04-12 00:00 |
18:24:24.03 |
-54:54:01.6 |
HIP 90231 |
4.01 |
| 2026-04-12 12:00 |
18:24:14.93 |
-54:55:08.3 |
HIP 90231 |
4.13 |
| 2026-04-13 00:00 |
18:24:05.66 |
-54:56:14.9 |
HIP 90231 |
4.91 |
| 2026-04-13 12:00 |
18:23:56.23 |
-54:57:21.3 |
HIP 90231 |
6.12 |
| 2026-04-14 00:00 |
18:23:46.62 |
-54:58:27.5 |
HIP 90193 |
6.30 |
| 2026-04-14 12:00 |
18:23:36.85 |
-54:59:33.6 |
HIP 90193 |
6.60 |
| 2026-04-15 00:00 |
18:23:26.91 |
-55:00:39.4 |
HIP 90193 |
7.34 |
| 2026-04-15 12:00 |
18:23:16.80 |
-55:01:45.1 |
HIP 90193 |
8.44 |
| 2026-04-16 00:00 |
18:23:06.52 |
-55:02:50.5 |
HIP 90193 |
9.77 |