メタデータ
| 項目 |
値 |
| Designation |
487P/Siding Spring |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2024-10-20T18:47:47.019840Z |
| Orbit solution date (soln_date, UTC) |
2025-09-30T13:39:51Z |
| Obs used |
1401 |
| NEO |
- |
| M1 |
12.600 |
| K1 |
12.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2024-07-05T08:27:27.360000Z |
| Discovery magnitude (MPC) |
19.10 V |
| Discovery observatory (MPC) |
I47 · Pierre Auger Observatory, Malargüe |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2022-08-22.0000000 |
| e |
0.64812734 |
| q (au) |
1.817415 |
| a (au) |
5.164980 |
| i (deg) |
39.365304 |
| Ω (om, deg) |
49.200900 |
| ω (w, deg) |
0.816323 |
| M (ma, deg) |
293.601469 |
等級
散乱 + 全体線形
$$
M_a = (15.177 + 2.625\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
15.177 |
| n |
2.625 |
| gf |
1.000 |
| gb |
-0.640 |
| 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 |
| 2024-07-05 |
2024-10-17 |
+24.0739 |
-6.359 |
| 2024-10-22 |
2025-04-19 |
-0.5771 |
+0.059 |
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 |
12:26:15.00 |
+32:00:59.6 |
HIP 60605 |
15.01 |
| 2026-06-01 12:00 |
12:26:10.93 |
+31:56:56.7 |
HIP 60605 |
12.17 |
| 2026-06-02 00:00 |
12:26:07.07 |
+31:52:53.0 |
HIP 60605 |
10.31 |
| 2026-06-02 12:00 |
12:26:03.44 |
+31:48:48.6 |
HIP 60605 |
9.98 |
| 2026-06-03 00:00 |
12:26:00.03 |
+31:44:43.4 |
HIP 60605 |
11.33 |
| 2026-06-03 12:00 |
12:25:56.84 |
+31:40:37.5 |
HIP 60605 |
13.87 |
| 2026-06-04 00:00 |
12:25:53.86 |
+31:36:30.9 |
HIP 60605 |
17.09 |
| 2026-06-04 12:00 |
12:25:51.11 |
+31:32:23.5 |
HIP 60605 |
20.68 |
| 2026-06-05 00:00 |
12:25:48.57 |
+31:28:15.5 |
HIP 60529 |
20.29 |
| 2026-06-05 12:00 |
12:25:46.25 |
+31:24:06.9 |
HIP 60529 |
17.82 |
| 2026-06-06 00:00 |
12:25:44.14 |
+31:19:57.6 |
HIP 60529 |
16.13 |
| 2026-06-06 12:00 |
12:25:42.25 |
+31:15:47.6 |
HIP 60529 |
15.45 |
| 2026-06-07 00:00 |
12:25:40.57 |
+31:11:37.1 |
HIP 60555 |
14.60 |
| 2026-06-07 12:00 |
12:25:39.10 |
+31:07:25.9 |
HIP 60555 |
11.99 |
| 2026-06-08 00:00 |
12:25:37.85 |
+31:03:14.2 |
HIP 60555 |
10.51 |
| 2026-06-08 12:00 |
12:25:36.80 |
+30:59:01.8 |
HIP 60555 |
10.65 |
| 2026-06-09 00:00 |
12:25:35.97 |
+30:54:48.9 |
HIP 60555 |
12.37 |
| 2026-06-09 12:00 |
12:25:35.34 |
+30:50:35.5 |
HIP 60555 |
15.14 |
| 2026-06-10 00:00 |
12:25:34.92 |
+30:46:21.6 |
HIP 60555 |
18.50 |
| 2026-06-10 12:00 |
12:25:34.71 |
+30:42:07.1 |
HIP 60555 |
22.19 |
| 2026-06-11 00:00 |
12:25:34.70 |
+30:37:52.1 |
HIP 60555 |
26.07 |
| 2026-06-11 12:00 |
12:25:34.90 |
+30:33:36.6 |
HIP 60669 |
26.83 |
| 2026-06-12 00:00 |
12:25:35.31 |
+30:29:20.7 |
HIP 60669 |
22.67 |
| 2026-06-12 12:00 |
12:25:35.91 |
+30:25:04.3 |
HIP 60669 |
18.53 |
| 2026-06-13 00:00 |
12:25:36.72 |
+30:20:47.4 |
HIP 60669 |
14.45 |
| 2026-06-13 12:00 |
12:25:37.73 |
+30:16:30.1 |
HIP 60669 |
10.50 |
| 2026-06-14 00:00 |
12:25:38.94 |
+30:12:12.4 |
HIP 60669 |
6.94 |
| 2026-06-14 12:00 |
12:25:40.34 |
+30:07:54.3 |
HIP 60669 |
4.77 |
| 2026-06-15 00:00 |
12:25:41.95 |
+30:03:35.8 |
HIP 60669 |
5.84 |
| 2026-06-15 12:00 |
12:25:43.75 |
+29:59:16.9 |
HIP 60597 |
6.85 |
| 2026-06-16 00:00 |
12:25:45.75 |
+29:54:57.7 |
HIP 60597 |
7.24 |
| 2026-06-16 12:00 |
12:25:47.94 |
+29:50:38.1 |
HIP 60597 |
9.82 |
| 2026-06-17 00:00 |
12:25:50.33 |
+29:46:18.2 |
HIP 60597 |
13.38 |
| 2026-06-17 12:00 |
12:25:52.91 |
+29:41:57.9 |
HIP 60597 |
17.34 |
| 2026-06-18 00:00 |
12:25:55.67 |
+29:37:37.4 |
HIP 60597 |
21.48 |
| 2026-06-18 12:00 |
12:25:58.63 |
+29:33:16.6 |
HIP 60675 |
19.81 |
| 2026-06-19 00:00 |
12:26:01.78 |
+29:28:55.5 |
HIP 60675 |
15.43 |
| 2026-06-19 12:00 |
12:26:05.11 |
+29:24:34.1 |
HIP 60675 |
11.05 |
| 2026-06-20 00:00 |
12:26:08.63 |
+29:20:12.5 |
HIP 60675 |
6.73 |
| 2026-06-20 12:00 |
12:26:12.34 |
+29:15:50.6 |
HIP 60675 |
2.80 |
| 2026-06-21 00:00 |
12:26:16.22 |
+29:11:28.5 |
HIP 60675 |
3.15 |
| 2026-06-21 12:00 |
12:26:20.29 |
+29:07:06.2 |
HIP 60675 |
7.21 |
| 2026-06-22 00:00 |
12:26:24.54 |
+29:02:43.7 |
HIP 60675 |
11.58 |