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) |
| 2026-07-29 00:00 |
12:38:37.56 |
+23:40:02.3 |
HIP 61681 |
2.08 |
| 2026-07-29 12:00 |
12:38:52.09 |
+23:35:48.3 |
HIP 61681 |
3.48 |
| 2026-07-30 00:00 |
12:39:06.72 |
+23:31:34.6 |
HIP 61681 |
8.84 |
| 2026-07-30 12:00 |
12:39:21.44 |
+23:27:21.2 |
HIP 61681 |
14.24 |
| 2026-07-31 00:00 |
12:39:36.26 |
+23:23:08.3 |
HIP 61681 |
19.65 |
| 2026-07-31 12:00 |
12:39:51.18 |
+23:18:55.6 |
HIP 61860 |
23.66 |
| 2026-08-01 00:00 |
12:40:06.18 |
+23:14:43.4 |
HIP 61860 |
18.33 |
| 2026-08-01 12:00 |
12:40:21.29 |
+23:10:31.5 |
HIP 61860 |
13.09 |
| 2026-08-02 00:00 |
12:40:36.48 |
+23:06:19.9 |
HIP 61860 |
8.12 |
| 2026-08-02 12:00 |
12:40:51.76 |
+23:02:08.8 |
HIP 61860 |
4.50 |
| 2026-08-03 00:00 |
12:41:07.14 |
+22:57:58.0 |
HIP 61860 |
5.89 |
| 2026-08-03 12:00 |
12:41:22.60 |
+22:53:47.6 |
HIP 61860 |
10.46 |
| 2026-08-04 00:00 |
12:41:38.16 |
+22:49:37.6 |
HIP 61860 |
15.65 |
| 2026-08-04 12:00 |
12:41:53.80 |
+22:45:27.9 |
HIP 61860 |
21.01 |
| 2026-08-05 00:00 |
12:42:09.53 |
+22:41:18.7 |
HIP 61860 |
26.44 |
| 2026-08-05 12:00 |
12:42:25.34 |
+22:37:09.8 |
HIP 61860 |
31.91 |
| 2026-08-06 00:00 |
12:42:41.24 |
+22:33:01.3 |
HIP 62150 |
35.11 |
| 2026-08-06 12:00 |
12:42:57.23 |
+22:28:53.2 |
HIP 62162 |
35.31 |
| 2026-08-07 00:00 |
12:43:13.30 |
+22:24:45.6 |
HIP 62162 |
29.82 |
| 2026-08-07 12:00 |
12:43:29.46 |
+22:20:38.3 |
HIP 62162 |
24.35 |
| 2026-08-08 00:00 |
12:43:45.70 |
+22:16:31.4 |
HIP 62162 |
18.94 |
| 2026-08-08 12:00 |
12:44:02.02 |
+22:12:25.0 |
HIP 62162 |
13.65 |
| 2026-08-09 00:00 |
12:44:18.42 |
+22:08:19.0 |
HIP 62162 |
8.74 |
| 2026-08-09 12:00 |
12:44:34.90 |
+22:04:13.4 |
HIP 62162 |
5.39 |
| 2026-08-10 00:00 |
12:44:51.46 |
+22:00:08.2 |
HIP 62162 |
6.69 |
| 2026-08-10 12:00 |
12:45:08.10 |
+21:56:03.5 |
HIP 62162 |
11.12 |
| 2026-08-11 00:00 |
12:45:24.82 |
+21:51:59.2 |
HIP 62280 |
11.70 |
| 2026-08-11 12:00 |
12:45:41.62 |
+21:47:55.3 |
HIP 62280 |
14.57 |
| 2026-08-12 00:00 |
12:45:58.49 |
+21:43:51.9 |
HIP 62334 |
11.50 |
| 2026-08-12 12:00 |
12:46:15.44 |
+21:39:48.9 |
HIP 62334 |
6.00 |
| 2026-08-13 00:00 |
12:46:32.47 |
+21:35:46.4 |
HIP 62334 |
1.93 |
| 2026-08-13 12:00 |
12:46:49.56 |
+21:31:44.4 |
HIP 62334 |
5.96 |
| 2026-08-14 00:00 |
12:47:06.73 |
+21:27:42.8 |
HIP 62334 |
11.48 |
| 2026-08-14 12:00 |
12:47:23.98 |
+21:23:41.7 |
HIP 62441 |
15.81 |
| 2026-08-15 00:00 |
12:47:41.29 |
+21:19:41.1 |
HIP 62441 |
18.65 |
| 2026-08-15 12:00 |
12:47:58.68 |
+21:15:40.9 |
HIP 62441 |
22.59 |
| 2026-08-16 00:00 |
12:48:16.13 |
+21:11:41.3 |
HIP 62344 |
26.02 |
| 2026-08-16 12:00 |
12:48:33.65 |
+21:07:42.1 |
HIP 62344 |
29.03 |
| 2026-08-17 00:00 |
12:48:51.24 |
+21:03:43.4 |
HIP 62494 |
26.32 |
| 2026-08-17 12:00 |
12:49:08.90 |
+20:59:45.2 |
HIP 62494 |
24.02 |
| 2026-08-18 00:00 |
12:49:26.62 |
+20:55:47.5 |
HIP 62494 |
22.97 |
| 2026-08-18 12:00 |
12:49:44.41 |
+20:51:50.4 |
HIP 62494 |
23.34 |
| 2026-08-19 00:00 |
12:50:02.26 |
+20:47:53.7 |
HIP 62686 |
18.33 |