C/1987 U3 (McNaught)
メタデータ
| 項目 |
値 |
| Designation |
C/1987 U3 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1987-12-11T22:32:44.332800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:36Z |
| Obs used |
106 |
| NEO |
- |
| M1 |
6.100 |
| K1 |
17.250 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1988-01-08.0000000 |
| e |
0.99855807 |
| q (au) |
0.841167 |
| a (au) |
583.363126 |
| i (deg) |
97.126481 |
| Ω (om, deg) |
261.341785 |
| ω (w, deg) |
17.409142 |
| M (ma, deg) |
0.001893 |
等級
散乱 + 全体線形
$$
M_a = (4.978 + 3.538\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
4.978 |
| n |
3.538 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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 |
| 1987-10-20 |
1987-11-12 |
+6.8257 |
+0.463 |
| 1987-12-27 |
1988-02-01 |
-7.5354 |
+0.143 |
| 1988-02-01 |
1988-03-14 |
+4.5436 |
-0.760 |
| 1988-03-14 |
1988-04-10 |
-12.5690 |
+3.795 |
| 1988-04-10 |
1988-05-10 |
+4.8167 |
-2.114 |
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) |
| 2026-02-03 00:00 |
05:17:53.17 |
+18:32:07.3 |
HIP 24612 |
17.41 |
| 2026-02-03 12:00 |
05:17:51.95 |
+18:32:07.3 |
HIP 24612 |
17.13 |
| 2026-02-04 00:00 |
05:17:50.73 |
+18:32:07.3 |
HIP 24612 |
16.86 |
| 2026-02-04 12:00 |
05:17:49.53 |
+18:32:07.4 |
HIP 24612 |
16.59 |
| 2026-02-05 00:00 |
05:17:48.35 |
+18:32:07.5 |
HIP 24612 |
16.33 |
| 2026-02-05 12:00 |
05:17:47.18 |
+18:32:07.5 |
HIP 24612 |
16.07 |
| 2026-02-06 00:00 |
05:17:46.03 |
+18:32:07.7 |
HIP 24612 |
15.82 |
| 2026-02-06 12:00 |
05:17:44.89 |
+18:32:07.8 |
HIP 24612 |
15.57 |
| 2026-02-07 00:00 |
05:17:43.77 |
+18:32:08.0 |
HIP 24612 |
15.32 |
| 2026-02-07 12:00 |
05:17:42.66 |
+18:32:08.2 |
HIP 24612 |
15.08 |
| 2026-02-08 00:00 |
05:17:41.57 |
+18:32:08.4 |
HIP 24612 |
14.84 |
| 2026-02-08 12:00 |
05:17:40.49 |
+18:32:08.7 |
HIP 24612 |
14.61 |
| 2026-02-09 00:00 |
05:17:39.43 |
+18:32:09.0 |
HIP 24612 |
14.38 |
| 2026-02-09 12:00 |
05:17:38.38 |
+18:32:09.3 |
HIP 24612 |
14.16 |
| 2026-02-10 00:00 |
05:17:37.35 |
+18:32:09.6 |
HIP 24612 |
13.94 |
| 2026-02-10 12:00 |
05:17:36.34 |
+18:32:10.0 |
HIP 24612 |
13.72 |
| 2026-02-11 00:00 |
05:17:35.34 |
+18:32:10.3 |
HIP 24612 |
13.51 |
| 2026-02-11 12:00 |
05:17:34.36 |
+18:32:10.8 |
HIP 24612 |
13.30 |
| 2026-02-12 00:00 |
05:17:33.39 |
+18:32:11.2 |
HIP 24612 |
13.10 |
| 2026-02-12 12:00 |
05:17:32.45 |
+18:32:11.6 |
HIP 24612 |
12.90 |
| 2026-02-13 00:00 |
05:17:31.51 |
+18:32:12.1 |
HIP 24612 |
12.71 |
| 2026-02-13 12:00 |
05:17:30.59 |
+18:32:12.6 |
HIP 24612 |
12.52 |
| 2026-02-14 00:00 |
05:17:29.69 |
+18:32:13.2 |
HIP 24612 |
12.34 |
| 2026-02-14 12:00 |
05:17:28.81 |
+18:32:13.7 |
HIP 24612 |
12.16 |
| 2026-02-15 00:00 |
05:17:27.94 |
+18:32:14.3 |
HIP 24612 |
11.98 |
| 2026-02-15 12:00 |
05:17:27.09 |
+18:32:14.9 |
HIP 24612 |
11.81 |
| 2026-02-16 00:00 |
05:17:26.26 |
+18:32:15.6 |
HIP 24612 |
11.64 |
| 2026-02-16 12:00 |
05:17:25.44 |
+18:32:16.2 |
HIP 24612 |
11.48 |
| 2026-02-17 00:00 |
05:17:24.64 |
+18:32:16.9 |
HIP 24612 |
11.33 |
| 2026-02-17 12:00 |
05:17:23.85 |
+18:32:17.6 |
HIP 24612 |
11.18 |
| 2026-02-18 00:00 |
05:17:23.08 |
+18:32:18.4 |
HIP 24612 |
11.03 |
| 2026-02-18 12:00 |
05:17:22.33 |
+18:32:19.1 |
HIP 24612 |
10.88 |
| 2026-02-19 00:00 |
05:17:21.60 |
+18:32:19.9 |
HIP 24612 |
10.75 |
| 2026-02-19 12:00 |
05:17:20.88 |
+18:32:20.7 |
HIP 24612 |
10.61 |
| 2026-02-20 00:00 |
05:17:20.18 |
+18:32:21.6 |
HIP 24612 |
10.48 |
| 2026-02-20 12:00 |
05:17:19.50 |
+18:32:22.4 |
HIP 24612 |
10.36 |
| 2026-02-21 00:00 |
05:17:18.83 |
+18:32:23.3 |
HIP 24612 |
10.24 |
| 2026-02-21 12:00 |
05:17:18.19 |
+18:32:24.2 |
HIP 24612 |
10.13 |
| 2026-02-22 00:00 |
05:17:17.56 |
+18:32:25.1 |
HIP 24612 |
10.02 |
| 2026-02-22 12:00 |
05:17:16.94 |
+18:32:26.1 |
HIP 24612 |
9.91 |
| 2026-02-23 00:00 |
05:17:16.34 |
+18:32:27.0 |
HIP 24612 |
9.81 |
| 2026-02-23 12:00 |
05:17:15.77 |
+18:32:28.0 |
HIP 24612 |
9.71 |
| 2026-02-24 00:00 |
05:17:15.20 |
+18:32:29.1 |
HIP 24612 |
9.62 |