メタデータ
| 項目 |
値 |
| Designation |
C/2009 K5 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2010-04-30T00:35:23.349120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:31Z |
| Obs used |
2488 |
| NEO |
- |
| M1 |
11.900 |
| K1 |
5.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2010-07-13.0000000 |
| e |
1.00083854 |
| q (au) |
1.422401 |
| a (au) |
-1696.276803 |
| i (deg) |
103.879390 |
| Ω (om, deg) |
257.856328 |
| ω (w, deg) |
66.174175 |
| M (ma, deg) |
0.001044 |
等級
散乱 + 全体線形
$$
M_a = (10.374 + 4.416\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.374 |
| n |
4.416 |
| gf |
0.999 |
| gb |
-0.589 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2009-05-27 |
2010-04-29 |
+0.0122 |
-1.630 |
| 2010-04-30 |
2010-09-19 |
+0.7909 |
-1.983 |
| 2010-09-19 |
2010-10-19 |
+22.6695 |
-9.980 |
| 2010-10-19 |
2011-11-26 |
-2.0385 |
+1.098 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
04:47:36.90 |
-18:40:45.8 |
HIP 22227 |
20.11 |
| 2026-07-29 12:00 |
04:47:38.96 |
-18:41:11.7 |
HIP 22227 |
20.74 |
| 2026-07-30 00:00 |
04:47:41.00 |
-18:41:37.8 |
HIP 22227 |
21.37 |
| 2026-07-30 12:00 |
04:47:43.01 |
-18:42:04.1 |
HIP 22227 |
22.00 |
| 2026-07-31 00:00 |
04:47:45.01 |
-18:42:30.7 |
HIP 22227 |
22.64 |
| 2026-07-31 12:00 |
04:47:46.97 |
-18:42:57.4 |
HIP 22227 |
23.27 |
| 2026-08-01 00:00 |
04:47:48.92 |
-18:43:24.3 |
HIP 22227 |
23.90 |
| 2026-08-01 12:00 |
04:47:50.84 |
-18:43:51.4 |
HIP 22227 |
24.53 |
| 2026-08-02 00:00 |
04:47:52.73 |
-18:44:18.7 |
HIP 22227 |
25.17 |
| 2026-08-02 12:00 |
04:47:54.61 |
-18:44:46.2 |
HIP 22227 |
25.80 |
| 2026-08-03 00:00 |
04:47:56.46 |
-18:45:13.9 |
HIP 22227 |
26.43 |
| 2026-08-03 12:00 |
04:47:58.28 |
-18:45:41.8 |
HIP 22227 |
27.06 |
| 2026-08-04 00:00 |
04:48:00.08 |
-18:46:09.8 |
HIP 22227 |
27.69 |
| 2026-08-04 12:00 |
04:48:01.86 |
-18:46:38.1 |
HIP 22227 |
28.32 |
| 2026-08-05 00:00 |
04:48:03.61 |
-18:47:06.5 |
HIP 22227 |
28.95 |
| 2026-08-05 12:00 |
04:48:05.34 |
-18:47:35.2 |
HIP 22227 |
29.57 |
| 2026-08-06 00:00 |
04:48:07.04 |
-18:48:04.0 |
HIP 22227 |
30.20 |
| 2026-08-06 12:00 |
04:48:08.72 |
-18:48:33.0 |
HIP 22227 |
30.82 |
| 2026-08-07 00:00 |
04:48:10.37 |
-18:49:02.1 |
HIP 22227 |
31.45 |
| 2026-08-07 12:00 |
04:48:12.00 |
-18:49:31.5 |
HIP 22227 |
32.07 |
| 2026-08-08 00:00 |
04:48:13.60 |
-18:50:01.0 |
HIP 22227 |
32.69 |
| 2026-08-08 12:00 |
04:48:15.18 |
-18:50:30.7 |
HIP 22227 |
33.31 |
| 2026-08-09 00:00 |
04:48:16.73 |
-18:51:00.6 |
HIP 22227 |
33.93 |
| 2026-08-09 12:00 |
04:48:18.25 |
-18:51:30.6 |
HIP 22227 |
34.55 |
| 2026-08-10 00:00 |
04:48:19.75 |
-18:52:00.8 |
HIP 22519 |
34.27 |
| 2026-08-10 12:00 |
04:48:21.22 |
-18:52:31.2 |
HIP 22519 |
33.89 |
| 2026-08-11 00:00 |
04:48:22.67 |
-18:53:01.8 |
HIP 22519 |
33.53 |
| 2026-08-11 12:00 |
04:48:24.09 |
-18:53:32.5 |
HIP 22519 |
33.18 |
| 2026-08-12 00:00 |
04:48:25.48 |
-18:54:03.3 |
HIP 22519 |
32.85 |
| 2026-08-12 12:00 |
04:48:26.85 |
-18:54:34.4 |
HIP 22519 |
32.53 |
| 2026-08-13 00:00 |
04:48:28.19 |
-18:55:05.6 |
HIP 22519 |
32.23 |
| 2026-08-13 12:00 |
04:48:29.50 |
-18:55:36.9 |
HIP 22519 |
31.94 |
| 2026-08-14 00:00 |
04:48:30.79 |
-18:56:08.4 |
HIP 22519 |
31.67 |
| 2026-08-14 12:00 |
04:48:32.04 |
-18:56:40.1 |
HIP 22519 |
31.41 |
| 2026-08-15 00:00 |
04:48:33.27 |
-18:57:11.9 |
HIP 22519 |
31.17 |
| 2026-08-15 12:00 |
04:48:34.48 |
-18:57:43.8 |
HIP 22519 |
30.94 |
| 2026-08-16 00:00 |
04:48:35.65 |
-18:58:15.9 |
HIP 22519 |
30.74 |
| 2026-08-16 12:00 |
04:48:36.80 |
-18:58:48.2 |
HIP 22519 |
30.55 |
| 2026-08-17 00:00 |
04:48:37.92 |
-18:59:20.5 |
HIP 22519 |
30.37 |
| 2026-08-17 12:00 |
04:48:39.01 |
-18:59:53.1 |
HIP 22519 |
30.22 |
| 2026-08-18 00:00 |
04:48:40.08 |
-19:00:25.7 |
HIP 22519 |
30.08 |
| 2026-08-18 12:00 |
04:48:41.11 |
-19:00:58.5 |
HIP 22519 |
29.97 |
| 2026-08-19 00:00 |
04:48:42.12 |
-19:01:31.4 |
HIP 22519 |
29.87 |