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 |
| 1987-12-27 |
1988-02-01 |
-7.4131 |
+0.143 |
| 1988-02-01 |
1988-02-18 |
+3.8294 |
-0.662 |
| 1988-02-18 |
1988-03-22 |
+3.4165 |
-0.549 |
| 1988-03-22 |
1988-05-10 |
-6.7830 |
+2.088 |
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) |
| 2026-06-01 00:00 |
05:20:14.18 |
+18:39:01.9 |
HIP 24910 |
3.78 |
| 2026-06-01 12:00 |
05:20:16.09 |
+18:39:03.6 |
HIP 24910 |
3.64 |
| 2026-06-02 00:00 |
05:20:17.99 |
+18:39:05.3 |
HIP 24910 |
3.55 |
| 2026-06-02 12:00 |
05:20:19.90 |
+18:39:06.9 |
HIP 24910 |
3.52 |
| 2026-06-03 00:00 |
05:20:21.82 |
+18:39:08.5 |
HIP 24910 |
3.55 |
| 2026-06-03 12:00 |
05:20:23.73 |
+18:39:10.1 |
HIP 24910 |
3.63 |
| 2026-06-04 00:00 |
05:20:25.65 |
+18:39:11.7 |
HIP 24910 |
3.76 |
| 2026-06-04 12:00 |
05:20:27.57 |
+18:39:13.3 |
HIP 24910 |
3.95 |
| 2026-06-05 00:00 |
05:20:29.49 |
+18:39:14.9 |
HIP 24910 |
4.17 |
| 2026-06-05 12:00 |
05:20:31.41 |
+18:39:16.4 |
HIP 24910 |
4.43 |
| 2026-06-06 00:00 |
05:20:33.34 |
+18:39:18.0 |
HIP 24910 |
4.73 |
| 2026-06-06 12:00 |
05:20:35.26 |
+18:39:19.5 |
HIP 24910 |
5.04 |
| 2026-06-07 00:00 |
05:20:37.19 |
+18:39:21.0 |
HIP 24910 |
5.38 |
| 2026-06-07 12:00 |
05:20:39.12 |
+18:39:22.4 |
HIP 24910 |
5.73 |
| 2026-06-08 00:00 |
05:20:41.05 |
+18:39:23.9 |
HIP 24910 |
6.10 |
| 2026-06-08 12:00 |
05:20:42.98 |
+18:39:25.3 |
HIP 24910 |
6.48 |
| 2026-06-09 00:00 |
05:20:44.91 |
+18:39:26.7 |
HIP 24910 |
6.86 |
| 2026-06-09 12:00 |
05:20:46.85 |
+18:39:28.1 |
HIP 24910 |
7.26 |
| 2026-06-10 00:00 |
05:20:48.78 |
+18:39:29.5 |
HIP 24910 |
7.66 |
| 2026-06-10 12:00 |
05:20:50.72 |
+18:39:30.9 |
HIP 24910 |
8.07 |
| 2026-06-11 00:00 |
05:20:52.65 |
+18:39:32.2 |
HIP 24910 |
8.49 |
| 2026-06-11 12:00 |
05:20:54.59 |
+18:39:33.5 |
HIP 24910 |
8.91 |
| 2026-06-12 00:00 |
05:20:56.53 |
+18:39:34.8 |
HIP 24910 |
9.33 |
| 2026-06-12 12:00 |
05:20:58.46 |
+18:39:36.1 |
HIP 24910 |
9.75 |
| 2026-06-13 00:00 |
05:21:00.40 |
+18:39:37.4 |
HIP 24910 |
10.18 |
| 2026-06-13 12:00 |
05:21:02.33 |
+18:39:38.6 |
HIP 24910 |
10.61 |
| 2026-06-14 00:00 |
05:21:04.27 |
+18:39:39.9 |
HIP 24910 |
11.05 |
| 2026-06-14 12:00 |
05:21:06.20 |
+18:39:41.1 |
HIP 24910 |
11.48 |
| 2026-06-15 00:00 |
05:21:08.14 |
+18:39:42.3 |
HIP 24910 |
11.92 |
| 2026-06-15 12:00 |
05:21:10.07 |
+18:39:43.4 |
HIP 24910 |
12.36 |
| 2026-06-16 00:00 |
05:21:12.01 |
+18:39:44.6 |
HIP 24910 |
12.79 |
| 2026-06-16 12:00 |
05:21:13.94 |
+18:39:45.7 |
HIP 24910 |
13.23 |
| 2026-06-17 00:00 |
05:21:15.87 |
+18:39:46.8 |
HIP 24910 |
13.67 |
| 2026-06-17 12:00 |
05:21:17.80 |
+18:39:47.9 |
HIP 24910 |
14.12 |
| 2026-06-18 00:00 |
05:21:19.73 |
+18:39:48.9 |
HIP 24910 |
14.56 |
| 2026-06-18 12:00 |
05:21:21.65 |
+18:39:50.0 |
HIP 24910 |
15.00 |
| 2026-06-19 00:00 |
05:21:23.58 |
+18:39:51.0 |
HIP 25035 |
15.06 |
| 2026-06-19 12:00 |
05:21:25.50 |
+18:39:52.0 |
HIP 25035 |
14.94 |
| 2026-06-20 00:00 |
05:21:27.42 |
+18:39:53.0 |
HIP 25035 |
14.82 |
| 2026-06-20 12:00 |
05:21:29.34 |
+18:39:53.9 |
HIP 25035 |
14.72 |
| 2026-06-21 00:00 |
05:21:31.25 |
+18:39:54.8 |
HIP 25035 |
14.64 |
| 2026-06-21 12:00 |
05:21:33.17 |
+18:39:55.8 |
HIP 25035 |
14.57 |
| 2026-06-22 00:00 |
05:21:35.08 |
+18:39:56.6 |
HIP 25035 |
14.51 |