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) |
| 2026-09-20 00:00 |
17:05:41.89 |
-51:59:45.6 |
HIP 83530 |
15.14 |
| 2026-09-20 12:00 |
17:05:42.80 |
-51:58:21.3 |
HIP 83530 |
14.57 |
| 2026-09-21 00:00 |
17:05:43.84 |
-51:56:57.4 |
HIP 83530 |
14.14 |
| 2026-09-21 12:00 |
17:05:45.00 |
-51:55:33.8 |
HIP 83530 |
13.86 |
| 2026-09-22 00:00 |
17:05:46.28 |
-51:54:10.5 |
HIP 83530 |
13.74 |
| 2026-09-22 12:00 |
17:05:47.70 |
-51:52:47.6 |
HIP 83530 |
13.78 |
| 2026-09-23 00:00 |
17:05:49.23 |
-51:51:25.1 |
HIP 83530 |
13.98 |
| 2026-09-23 12:00 |
17:05:50.89 |
-51:50:02.9 |
HIP 83530 |
14.33 |
| 2026-09-24 00:00 |
17:05:52.67 |
-51:48:41.1 |
HIP 83530 |
14.82 |
| 2026-09-24 12:00 |
17:05:54.57 |
-51:47:19.6 |
HIP 83530 |
15.44 |
| 2026-09-25 00:00 |
17:05:56.59 |
-51:45:58.5 |
HIP 83530 |
16.17 |
| 2026-09-25 12:00 |
17:05:58.73 |
-51:44:37.8 |
HIP 83530 |
17.00 |
| 2026-09-26 00:00 |
17:06:01.00 |
-51:43:17.4 |
HIP 83530 |
17.91 |
| 2026-09-26 12:00 |
17:06:03.37 |
-51:41:57.5 |
HIP 83530 |
18.89 |
| 2026-09-27 00:00 |
17:06:05.87 |
-51:40:37.9 |
HIP 83530 |
19.93 |
| 2026-09-27 12:00 |
17:06:08.49 |
-51:39:18.7 |
HIP 83530 |
21.02 |
| 2026-09-28 00:00 |
17:06:11.22 |
-51:37:59.8 |
HIP 83530 |
22.16 |
| 2026-09-28 12:00 |
17:06:14.06 |
-51:36:41.4 |
HIP 83530 |
23.33 |
| 2026-09-29 00:00 |
17:06:17.02 |
-51:35:23.4 |
HIP 83530 |
24.53 |
| 2026-09-29 12:00 |
17:06:20.10 |
-51:34:05.7 |
HIP 83530 |
25.76 |
| 2026-09-30 00:00 |
17:06:23.29 |
-51:32:48.4 |
HIP 83530 |
27.01 |
| 2026-09-30 12:00 |
17:06:26.59 |
-51:31:31.6 |
HIP 83530 |
28.28 |
| 2026-10-01 00:00 |
17:06:30.01 |
-51:30:15.1 |
HIP 83530 |
29.56 |
| 2026-10-01 12:00 |
17:06:33.53 |
-51:28:59.0 |
HIP 83773 |
29.75 |
| 2026-10-02 00:00 |
17:06:37.17 |
-51:27:43.4 |
HIP 83773 |
28.39 |
| 2026-10-02 12:00 |
17:06:40.92 |
-51:26:28.1 |
HIP 83773 |
27.04 |
| 2026-10-03 00:00 |
17:06:44.78 |
-51:25:13.3 |
HIP 83773 |
25.69 |
| 2026-10-03 12:00 |
17:06:48.75 |
-51:23:58.8 |
HIP 83773 |
24.35 |
| 2026-10-04 00:00 |
17:06:52.82 |
-51:22:44.8 |
HIP 83773 |
23.02 |
| 2026-10-04 12:00 |
17:06:57.00 |
-51:21:31.2 |
HIP 83773 |
21.70 |
| 2026-10-05 00:00 |
17:07:01.30 |
-51:20:18.0 |
HIP 83773 |
20.40 |
| 2026-10-05 12:00 |
17:07:05.69 |
-51:19:05.3 |
HIP 83773 |
19.11 |
| 2026-10-06 00:00 |
17:07:10.20 |
-51:17:52.9 |
HIP 83773 |
17.85 |
| 2026-10-06 12:00 |
17:07:14.81 |
-51:16:41.0 |
HIP 83773 |
16.61 |
| 2026-10-07 00:00 |
17:07:19.52 |
-51:15:29.5 |
HIP 83773 |
15.41 |
| 2026-10-07 12:00 |
17:07:24.33 |
-51:14:18.5 |
HIP 83773 |
14.26 |
| 2026-10-08 00:00 |
17:07:29.25 |
-51:13:07.9 |
HIP 83773 |
13.16 |
| 2026-10-08 12:00 |
17:07:34.28 |
-51:11:57.7 |
HIP 83773 |
12.14 |
| 2026-10-09 00:00 |
17:07:39.40 |
-51:10:47.9 |
HIP 83773 |
11.21 |
| 2026-10-09 12:00 |
17:07:44.62 |
-51:09:38.6 |
HIP 83773 |
10.41 |
| 2026-10-10 00:00 |
17:07:49.95 |
-51:08:29.8 |
HIP 83773 |
9.76 |
| 2026-10-10 12:00 |
17:07:55.37 |
-51:07:21.3 |
HIP 83773 |
9.30 |
| 2026-10-11 00:00 |
17:08:00.89 |
-51:06:13.4 |
HIP 83773 |
9.07 |