メタデータ
| 項目 |
値 |
| Designation |
C/2005 S4 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2007-07-18T15:31:21.316800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:53Z |
| Obs used |
580 |
| NEO |
- |
| M1 |
9.900 |
| K1 |
5.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2007-06-06.0000000 |
| e |
0.99897119 |
| q (au) |
5.850108 |
| a (au) |
5686.269098 |
| i (deg) |
107.958958 |
| Ω (om, deg) |
318.290291 |
| ω (w, deg) |
31.453945 |
| M (ma, deg) |
359.999902 |
等級
散乱 + 全体線形
$$
M_a = (6.966 + 3.745\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
6.966 |
| n |
3.745 |
| gf |
0.995 |
| gb |
-0.897 |
| k |
0.999 |
| 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 |
| 2005-07-27 |
2007-07-16 |
-1.0253 |
+0.679 |
| 2007-07-19 |
2008-10-06 |
+18.7523 |
-14.647 |
| 2008-10-06 |
2009-07-23 |
+4.6293 |
-3.301 |
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) |
| 2026-09-20 00:00 |
10:09:31.77 |
+27:39:36.5 |
HIP 49759 |
19.40 |
| 2026-09-20 12:00 |
10:09:34.58 |
+27:39:24.7 |
HIP 49759 |
19.65 |
| 2026-09-21 00:00 |
10:09:37.38 |
+27:39:13.0 |
HIP 49759 |
19.91 |
| 2026-09-21 12:00 |
10:09:40.17 |
+27:39:01.5 |
HIP 49759 |
20.19 |
| 2026-09-22 00:00 |
10:09:42.94 |
+27:38:50.2 |
HIP 49759 |
20.48 |
| 2026-09-22 12:00 |
10:09:45.70 |
+27:38:39.0 |
HIP 49759 |
20.78 |
| 2026-09-23 00:00 |
10:09:48.45 |
+27:38:28.0 |
HIP 49759 |
21.09 |
| 2026-09-23 12:00 |
10:09:51.18 |
+27:38:17.2 |
HIP 49759 |
21.42 |
| 2026-09-24 00:00 |
10:09:53.89 |
+27:38:06.5 |
HIP 49759 |
21.75 |
| 2026-09-24 12:00 |
10:09:56.60 |
+27:37:56.0 |
HIP 49759 |
22.10 |
| 2026-09-25 00:00 |
10:09:59.28 |
+27:37:45.7 |
HIP 49759 |
22.45 |
| 2026-09-25 12:00 |
10:10:01.96 |
+27:37:35.5 |
HIP 49759 |
22.81 |
| 2026-09-26 00:00 |
10:10:04.61 |
+27:37:25.5 |
HIP 49759 |
23.17 |
| 2026-09-26 12:00 |
10:10:07.26 |
+27:37:15.7 |
HIP 49759 |
23.55 |
| 2026-09-27 00:00 |
10:10:09.88 |
+27:37:06.1 |
HIP 49924 |
23.19 |
| 2026-09-27 12:00 |
10:10:12.49 |
+27:36:56.6 |
HIP 49924 |
22.82 |
| 2026-09-28 00:00 |
10:10:15.09 |
+27:36:47.3 |
HIP 49924 |
22.46 |
| 2026-09-28 12:00 |
10:10:17.67 |
+27:36:38.1 |
HIP 49924 |
22.10 |
| 2026-09-29 00:00 |
10:10:20.23 |
+27:36:29.2 |
HIP 49924 |
21.76 |
| 2026-09-29 12:00 |
10:10:22.77 |
+27:36:20.4 |
HIP 49924 |
21.43 |
| 2026-09-30 00:00 |
10:10:25.30 |
+27:36:11.8 |
HIP 49924 |
21.12 |
| 2026-09-30 12:00 |
10:10:27.82 |
+27:36:03.3 |
HIP 49924 |
20.81 |
| 2026-10-01 00:00 |
10:10:30.31 |
+27:35:55.0 |
HIP 49924 |
20.52 |
| 2026-10-01 12:00 |
10:10:32.79 |
+27:35:46.9 |
HIP 49924 |
20.23 |
| 2026-10-02 00:00 |
10:10:35.25 |
+27:35:39.0 |
HIP 49924 |
19.97 |
| 2026-10-02 12:00 |
10:10:37.69 |
+27:35:31.3 |
HIP 49924 |
19.71 |
| 2026-10-03 00:00 |
10:10:40.12 |
+27:35:23.7 |
HIP 49924 |
19.46 |
| 2026-10-03 12:00 |
10:10:42.53 |
+27:35:16.3 |
HIP 49924 |
19.23 |
| 2026-10-04 00:00 |
10:10:44.92 |
+27:35:09.1 |
HIP 49924 |
19.01 |
| 2026-10-04 12:00 |
10:10:47.29 |
+27:35:02.1 |
HIP 49924 |
18.81 |
| 2026-10-05 00:00 |
10:10:49.64 |
+27:34:55.2 |
HIP 49924 |
18.62 |
| 2026-10-05 12:00 |
10:10:51.97 |
+27:34:48.6 |
HIP 49924 |
18.44 |
| 2026-10-06 00:00 |
10:10:54.28 |
+27:34:42.1 |
HIP 49924 |
18.27 |
| 2026-10-06 12:00 |
10:10:56.58 |
+27:34:35.8 |
HIP 49924 |
18.12 |
| 2026-10-07 00:00 |
10:10:58.85 |
+27:34:29.6 |
HIP 49924 |
17.97 |
| 2026-10-07 12:00 |
10:11:01.11 |
+27:34:23.7 |
HIP 49924 |
17.85 |
| 2026-10-08 00:00 |
10:11:03.34 |
+27:34:17.9 |
HIP 49924 |
17.73 |
| 2026-10-08 12:00 |
10:11:05.56 |
+27:34:12.3 |
HIP 49924 |
17.63 |
| 2026-10-09 00:00 |
10:11:07.75 |
+27:34:06.9 |
HIP 49924 |
17.54 |
| 2026-10-09 12:00 |
10:11:09.93 |
+27:34:01.7 |
HIP 49924 |
17.46 |
| 2026-10-10 00:00 |
10:11:12.08 |
+27:33:56.7 |
HIP 49924 |
17.39 |
| 2026-10-10 12:00 |
10:11:14.22 |
+27:33:51.9 |
HIP 49924 |
17.34 |
| 2026-10-11 00:00 |
10:11:16.33 |
+27:33:47.2 |
HIP 49924 |
17.29 |