メタデータ
| 項目 |
値 |
| Designation |
C/2021 K2 (MASTER) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-09-09T03:37:31.964160Z |
| Orbit solution date (soln_date, UTC) |
2022-07-16T01:42:47Z |
| Obs used |
80 |
| NEO |
- |
| M1 |
8.000 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-05-22T23:28:21.792000Z |
| Discovery magnitude (MPC) |
18.70 R |
| Discovery observatory (MPC) |
K95 · MASTER-SAAO Observatory, Sutherland |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2021-10-19.0000000 |
| e |
1.00120074 |
| q (au) |
5.467026 |
| a (au) |
-4553.055334 |
| i (deg) |
100.845478 |
| Ω (om, deg) |
282.245058 |
| ω (w, deg) |
343.321986 |
| M (ma, deg) |
0.000128 |
等級
散乱 + 全体線形
$$
M_a = (10.807 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.807 |
| n |
2.000 |
| gf |
0.997 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
9.959 |
| 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 |
17:35:23.89 |
+54:11:27.9 |
HIP 86354 |
29.95 |
| 2026-03-26 12:00 |
17:35:19.14 |
+54:14:25.3 |
HIP 86354 |
31.27 |
| 2026-03-27 00:00 |
17:35:14.24 |
+54:17:22.5 |
HIP 86354 |
32.84 |
| 2026-03-27 12:00 |
17:35:09.19 |
+54:20:19.3 |
HIP 85759 |
32.41 |
| 2026-03-28 00:00 |
17:35:03.98 |
+54:23:15.9 |
HIP 85759 |
31.67 |
| 2026-03-28 12:00 |
17:34:58.63 |
+54:26:12.2 |
HIP 85759 |
31.20 |
| 2026-03-29 00:00 |
17:34:53.12 |
+54:29:08.2 |
HIP 85759 |
30.99 |
| 2026-03-29 12:00 |
17:34:47.46 |
+54:32:03.8 |
HIP 86058 |
28.45 |
| 2026-03-30 00:00 |
17:34:41.64 |
+54:34:59.1 |
HIP 86058 |
25.71 |
| 2026-03-30 12:00 |
17:34:35.68 |
+54:37:54.1 |
HIP 86058 |
23.06 |
| 2026-03-31 00:00 |
17:34:29.56 |
+54:40:48.6 |
HIP 86058 |
20.53 |
| 2026-03-31 12:00 |
17:34:23.29 |
+54:43:42.9 |
HIP 86058 |
18.17 |
| 2026-04-01 00:00 |
17:34:16.87 |
+54:46:36.7 |
HIP 86058 |
16.05 |
| 2026-04-01 12:00 |
17:34:10.29 |
+54:49:30.2 |
HIP 86058 |
14.30 |
| 2026-04-02 00:00 |
17:34:03.57 |
+54:52:23.2 |
HIP 86058 |
13.04 |
| 2026-04-02 12:00 |
17:33:56.69 |
+54:55:15.8 |
HIP 86058 |
12.45 |
| 2026-04-03 00:00 |
17:33:49.65 |
+54:58:08.0 |
HIP 86058 |
12.60 |
| 2026-04-03 12:00 |
17:33:42.47 |
+55:00:59.8 |
HIP 86058 |
13.47 |
| 2026-04-04 00:00 |
17:33:35.13 |
+55:03:51.1 |
HIP 85829 |
13.07 |
| 2026-04-04 12:00 |
17:33:27.64 |
+55:06:42.0 |
HIP 85829 |
10.89 |
| 2026-04-05 00:00 |
17:33:20.00 |
+55:09:32.3 |
HIP 85829 |
9.19 |
| 2026-04-05 12:00 |
17:33:12.20 |
+55:12:22.2 |
HIP 85829 |
8.28 |
| 2026-04-06 00:00 |
17:33:04.25 |
+55:15:11.6 |
HIP 85829 |
8.42 |
| 2026-04-06 12:00 |
17:32:56.15 |
+55:18:00.5 |
HIP 85819 |
9.54 |
| 2026-04-07 00:00 |
17:32:47.89 |
+55:20:48.9 |
HIP 85819 |
11.13 |
| 2026-04-07 12:00 |
17:32:39.49 |
+55:23:36.7 |
HIP 85819 |
13.23 |
| 2026-04-08 00:00 |
17:32:30.93 |
+55:26:24.0 |
HIP 85819 |
15.63 |
| 2026-04-08 12:00 |
17:32:22.21 |
+55:29:10.8 |
HIP 85819 |
18.21 |
| 2026-04-09 00:00 |
17:32:13.35 |
+55:31:57.0 |
HIP 85819 |
20.91 |
| 2026-04-09 12:00 |
17:32:04.33 |
+55:34:42.6 |
HIP 85819 |
23.68 |
| 2026-04-10 00:00 |
17:31:55.16 |
+55:37:27.6 |
HIP 85819 |
26.50 |
| 2026-04-10 12:00 |
17:31:45.84 |
+55:40:12.0 |
HIP 85819 |
29.36 |
| 2026-04-11 00:00 |
17:31:36.37 |
+55:42:55.8 |
HIP 85819 |
32.25 |
| 2026-04-11 12:00 |
17:31:26.75 |
+55:45:38.9 |
HIP 85819 |
35.15 |
| 2026-04-12 00:00 |
17:31:16.97 |
+55:48:21.4 |
HIP 85466 |
35.54 |
| 2026-04-12 12:00 |
17:31:07.04 |
+55:51:03.3 |
HIP 85466 |
32.82 |
| 2026-04-13 00:00 |
17:30:56.97 |
+55:53:44.5 |
HIP 85466 |
30.16 |
| 2026-04-13 12:00 |
17:30:46.74 |
+55:56:25.1 |
HIP 85466 |
27.56 |
| 2026-04-14 00:00 |
17:30:36.36 |
+55:59:04.9 |
HIP 85466 |
25.05 |
| 2026-04-14 12:00 |
17:30:25.83 |
+56:01:44.1 |
HIP 85466 |
22.66 |
| 2026-04-15 00:00 |
17:30:15.15 |
+56:04:22.5 |
HIP 85466 |
20.42 |
| 2026-04-15 12:00 |
17:30:04.33 |
+56:07:00.2 |
HIP 85466 |
18.40 |
| 2026-04-16 00:00 |
17:29:53.35 |
+56:09:37.2 |
HIP 85466 |
16.67 |