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
$$
M_a = (10.374 + 4.415\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.374 |
| n |
4.415 |
| gf |
1.000 |
| 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 |
+0.0125 |
-1.630 |
| 2010-04-30 |
2010-09-19 |
+0.7906 |
-1.983 |
| 2010-09-19 |
2010-10-19 |
+22.6718 |
-9.981 |
| 2010-10-19 |
2011-11-26 |
-2.0378 |
+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) |
| 2026-05-12 00:00 |
04:39:36.62 |
-18:24:04.1 |
HIP 21561 |
26.98 |
| 2026-05-12 12:00 |
04:39:39.85 |
-18:23:50.2 |
HIP 21561 |
27.71 |
| 2026-05-13 00:00 |
04:39:43.10 |
-18:23:36.5 |
HIP 21561 |
28.44 |
| 2026-05-13 12:00 |
04:39:46.35 |
-18:23:23.1 |
HIP 21561 |
29.18 |
| 2026-05-14 00:00 |
04:39:49.62 |
-18:23:10.0 |
HIP 21561 |
29.92 |
| 2026-05-14 12:00 |
04:39:52.89 |
-18:22:57.1 |
HIP 21561 |
30.67 |
| 2026-05-15 00:00 |
04:39:56.17 |
-18:22:44.4 |
HIP 21561 |
31.42 |
| 2026-05-15 12:00 |
04:39:59.46 |
-18:22:32.0 |
HIP 21561 |
32.18 |
| 2026-05-16 00:00 |
04:40:02.76 |
-18:22:19.9 |
HIP 21561 |
32.95 |
| 2026-05-16 12:00 |
04:40:06.06 |
-18:22:08.0 |
HIP 21561 |
33.72 |
| 2026-05-17 00:00 |
04:40:09.38 |
-18:21:56.3 |
HIP 21561 |
34.49 |
| 2026-05-17 12:00 |
04:40:12.70 |
-18:21:44.9 |
HIP 21561 |
35.27 |
| 2026-05-18 00:00 |
04:40:16.02 |
-18:21:33.8 |
HIP 21561 |
36.04 |
| 2026-05-18 12:00 |
04:40:19.36 |
-18:21:22.9 |
HIP 21561 |
36.83 |
| 2026-05-19 00:00 |
04:40:22.70 |
-18:21:12.3 |
HIP 21561 |
37.61 |
| 2026-05-19 12:00 |
04:40:26.05 |
-18:21:01.9 |
HIP 21561 |
38.40 |
| 2026-05-20 00:00 |
04:40:29.40 |
-18:20:51.8 |
HIP 21561 |
39.19 |
| 2026-05-20 12:00 |
04:40:32.76 |
-18:20:42.0 |
HIP 21561 |
39.99 |
| 2026-05-21 00:00 |
04:40:36.13 |
-18:20:32.4 |
HIP 21646 |
40.59 |
| 2026-05-21 12:00 |
04:40:39.50 |
-18:20:23.0 |
HIP 21646 |
41.19 |
| 2026-05-22 00:00 |
04:40:42.87 |
-18:20:14.0 |
HIP 21646 |
41.80 |
| 2026-05-22 12:00 |
04:40:46.26 |
-18:20:05.2 |
HIP 21646 |
42.41 |
| 2026-05-23 00:00 |
04:40:49.64 |
-18:19:56.6 |
HIP 21925 |
42.02 |
| 2026-05-23 12:00 |
04:40:53.03 |
-18:19:48.3 |
HIP 21925 |
41.37 |
| 2026-05-24 00:00 |
04:40:56.43 |
-18:19:40.3 |
HIP 21925 |
40.72 |
| 2026-05-24 12:00 |
04:40:59.82 |
-18:19:32.5 |
HIP 21925 |
40.09 |
| 2026-05-25 00:00 |
04:41:03.23 |
-18:19:25.0 |
HIP 21925 |
39.46 |
| 2026-05-25 12:00 |
04:41:06.63 |
-18:19:17.8 |
HIP 21925 |
38.84 |
| 2026-05-26 00:00 |
04:41:10.04 |
-18:19:10.8 |
HIP 21925 |
38.23 |
| 2026-05-26 12:00 |
04:41:13.45 |
-18:19:04.1 |
HIP 21925 |
37.64 |
| 2026-05-27 00:00 |
04:41:16.87 |
-18:18:57.7 |
HIP 21925 |
37.05 |
| 2026-05-27 12:00 |
04:41:20.29 |
-18:18:51.5 |
HIP 21925 |
36.48 |
| 2026-05-28 00:00 |
04:41:23.71 |
-18:18:45.6 |
HIP 21925 |
35.92 |
| 2026-05-28 12:00 |
04:41:27.13 |
-18:18:39.9 |
HIP 21925 |
35.37 |
| 2026-05-29 00:00 |
04:41:30.56 |
-18:18:34.5 |
HIP 21925 |
34.84 |
| 2026-05-29 12:00 |
04:41:33.98 |
-18:18:29.4 |
HIP 21925 |
34.32 |
| 2026-05-30 00:00 |
04:41:37.41 |
-18:18:24.5 |
HIP 21925 |
33.82 |
| 2026-05-30 12:00 |
04:41:40.84 |
-18:18:19.9 |
HIP 21925 |
33.33 |
| 2026-05-31 00:00 |
04:41:44.27 |
-18:18:15.6 |
HIP 21925 |
32.86 |
| 2026-05-31 12:00 |
04:41:47.70 |
-18:18:11.6 |
HIP 21925 |
32.41 |
| 2026-06-01 00:00 |
04:41:51.14 |
-18:18:07.8 |
HIP 21925 |
31.98 |
| 2026-06-01 12:00 |
04:41:54.57 |
-18:18:04.3 |
HIP 21925 |
31.57 |
| 2026-06-02 00:00 |
04:41:58.00 |
-18:18:01.0 |
HIP 21925 |
31.17 |