メタデータ
| 項目 |
値 |
| Designation |
C/2007 P1 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2007-04-03T06:43:48.607680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:10Z |
| Obs used |
16 |
| NEO |
- |
| M1 |
13.600 |
| K1 |
10.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2007-08-10.0000000 |
| e |
1.00042564 |
| q (au) |
0.522246 |
| a (au) |
-1226.959668 |
| i (deg) |
119.181662 |
| Ω (om, deg) |
187.061353 |
| ω (w, deg) |
90.192851 |
| M (ma, deg) |
0.002952 |
等級
散乱 + 全体線形
$$
M_a = (17.762 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
17.762 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-1.000 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
23:00:31.01 |
-74:33:30.2 |
HIP 114063 |
25.15 |
| 2026-09-20 12:00 |
23:00:20.99 |
-74:33:27.2 |
HIP 114063 |
25.75 |
| 2026-09-21 00:00 |
23:00:10.99 |
-74:33:23.8 |
HIP 114063 |
26.35 |
| 2026-09-21 12:00 |
23:00:01.02 |
-74:33:20.0 |
HIP 114063 |
26.97 |
| 2026-09-22 00:00 |
22:59:51.07 |
-74:33:15.9 |
HIP 114063 |
27.58 |
| 2026-09-22 12:00 |
22:59:41.16 |
-74:33:11.4 |
HIP 113118 |
27.85 |
| 2026-09-23 00:00 |
22:59:31.27 |
-74:33:06.4 |
HIP 113118 |
27.43 |
| 2026-09-23 12:00 |
22:59:21.41 |
-74:33:01.2 |
HIP 113118 |
27.02 |
| 2026-09-24 00:00 |
22:59:11.57 |
-74:32:55.5 |
HIP 113118 |
26.63 |
| 2026-09-24 12:00 |
22:59:01.77 |
-74:32:49.5 |
HIP 113118 |
26.26 |
| 2026-09-25 00:00 |
22:58:52.01 |
-74:32:43.0 |
HIP 113118 |
25.90 |
| 2026-09-25 12:00 |
22:58:42.27 |
-74:32:36.2 |
HIP 113118 |
25.56 |
| 2026-09-26 00:00 |
22:58:32.57 |
-74:32:29.1 |
HIP 113118 |
25.23 |
| 2026-09-26 12:00 |
22:58:22.90 |
-74:32:21.5 |
HIP 113118 |
24.93 |
| 2026-09-27 00:00 |
22:58:13.26 |
-74:32:13.6 |
HIP 113118 |
24.65 |
| 2026-09-27 12:00 |
22:58:03.67 |
-74:32:05.4 |
HIP 113118 |
24.38 |
| 2026-09-28 00:00 |
22:57:54.11 |
-74:31:56.7 |
HIP 113118 |
24.14 |
| 2026-09-28 12:00 |
22:57:44.58 |
-74:31:47.7 |
HIP 113118 |
23.92 |
| 2026-09-29 00:00 |
22:57:35.10 |
-74:31:38.3 |
HIP 113118 |
23.72 |
| 2026-09-29 12:00 |
22:57:25.65 |
-74:31:28.6 |
HIP 113118 |
23.54 |
| 2026-09-30 00:00 |
22:57:16.24 |
-74:31:18.4 |
HIP 113118 |
23.39 |
| 2026-09-30 12:00 |
22:57:06.88 |
-74:31:08.0 |
HIP 113118 |
23.26 |
| 2026-10-01 00:00 |
22:56:57.55 |
-74:30:57.1 |
HIP 113118 |
23.15 |
| 2026-10-01 12:00 |
22:56:48.27 |
-74:30:45.9 |
HIP 113118 |
23.07 |
| 2026-10-02 00:00 |
22:56:39.03 |
-74:30:34.3 |
HIP 113118 |
23.01 |
| 2026-10-02 12:00 |
22:56:29.84 |
-74:30:22.4 |
HIP 113118 |
22.97 |
| 2026-10-03 00:00 |
22:56:20.69 |
-74:30:10.1 |
HIP 113118 |
22.96 |
| 2026-10-03 12:00 |
22:56:11.59 |
-74:29:57.4 |
HIP 113118 |
22.98 |
| 2026-10-04 00:00 |
22:56:02.53 |
-74:29:44.4 |
HIP 113118 |
23.01 |
| 2026-10-04 12:00 |
22:55:53.52 |
-74:29:31.1 |
HIP 113118 |
23.08 |
| 2026-10-05 00:00 |
22:55:44.56 |
-74:29:17.3 |
HIP 113118 |
23.16 |
| 2026-10-05 12:00 |
22:55:35.64 |
-74:29:03.3 |
HIP 113118 |
23.27 |
| 2026-10-06 00:00 |
22:55:26.78 |
-74:28:48.8 |
HIP 113118 |
23.40 |
| 2026-10-06 12:00 |
22:55:17.97 |
-74:28:34.0 |
HIP 113118 |
23.56 |
| 2026-10-07 00:00 |
22:55:09.21 |
-74:28:18.9 |
HIP 113118 |
23.73 |
| 2026-10-07 12:00 |
22:55:00.50 |
-74:28:03.4 |
HIP 113118 |
23.93 |
| 2026-10-08 00:00 |
22:54:51.84 |
-74:27:47.6 |
HIP 113118 |
24.15 |
| 2026-10-08 12:00 |
22:54:43.24 |
-74:27:31.4 |
HIP 113118 |
24.39 |
| 2026-10-09 00:00 |
22:54:34.69 |
-74:27:14.9 |
HIP 113118 |
24.65 |
| 2026-10-09 12:00 |
22:54:26.20 |
-74:26:58.0 |
HIP 113118 |
24.93 |
| 2026-10-10 00:00 |
22:54:17.77 |
-74:26:40.8 |
HIP 113118 |
25.22 |
| 2026-10-10 12:00 |
22:54:09.39 |
-74:26:23.3 |
HIP 113118 |
25.53 |
| 2026-10-11 00:00 |
22:54:01.07 |
-74:26:05.4 |
HIP 113118 |
25.86 |