487P/Siding Spring
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
$$
M_a = (15.264 + 2.482\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
15.264 |
| n |
2.482 |
| gf |
1.000 |
| gb |
-0.639 |
| 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 |
+24.3077 |
-6.416 |
| 2024-10-22 |
2025-04-19 |
-0.1753 |
-0.048 |
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 |
13:37:50.68 |
+32:31:42.9 |
HIP 66654 |
25.15 |
| 2026-02-03 12:00 |
13:37:45.68 |
+32:34:52.4 |
HIP 66654 |
27.06 |
| 2026-02-04 00:00 |
13:37:40.37 |
+32:38:02.2 |
HIP 66654 |
29.29 |
| 2026-02-04 12:00 |
13:37:34.77 |
+32:41:12.5 |
HIP 66654 |
31.77 |
| 2026-02-05 00:00 |
13:37:28.86 |
+32:44:23.1 |
HIP 66654 |
34.46 |
| 2026-02-05 12:00 |
13:37:22.66 |
+32:47:34.0 |
HIP 66654 |
37.32 |
| 2026-02-06 00:00 |
13:37:16.16 |
+32:50:45.1 |
HIP 66239 |
38.07 |
| 2026-02-06 12:00 |
13:37:09.36 |
+32:53:56.5 |
HIP 66239 |
35.40 |
| 2026-02-07 00:00 |
13:37:02.26 |
+32:57:08.1 |
HIP 66239 |
32.83 |
| 2026-02-07 12:00 |
13:36:54.86 |
+33:00:19.9 |
HIP 66239 |
30.39 |
| 2026-02-08 00:00 |
13:36:47.16 |
+33:03:31.8 |
HIP 66239 |
28.13 |
| 2026-02-08 12:00 |
13:36:39.16 |
+33:06:43.8 |
HIP 66239 |
26.10 |
| 2026-02-09 00:00 |
13:36:30.86 |
+33:09:55.9 |
HIP 66239 |
24.39 |
| 2026-02-09 12:00 |
13:36:22.26 |
+33:13:08.0 |
HIP 66239 |
23.06 |
| 2026-02-10 00:00 |
13:36:13.37 |
+33:16:20.1 |
HIP 66239 |
22.21 |
| 2026-02-10 12:00 |
13:36:04.17 |
+33:19:32.1 |
HIP 66239 |
21.91 |
| 2026-02-11 00:00 |
13:35:54.68 |
+33:22:44.1 |
HIP 66239 |
22.20 |
| 2026-02-11 12:00 |
13:35:44.89 |
+33:25:55.9 |
HIP 66239 |
23.06 |
| 2026-02-12 00:00 |
13:35:34.81 |
+33:29:07.6 |
HIP 66239 |
24.46 |
| 2026-02-12 12:00 |
13:35:24.43 |
+33:32:19.1 |
HIP 66193 |
25.18 |
| 2026-02-13 00:00 |
13:35:13.75 |
+33:35:30.4 |
HIP 66128 |
23.47 |
| 2026-02-13 12:00 |
13:35:02.78 |
+33:38:41.3 |
HIP 66128 |
20.86 |
| 2026-02-14 00:00 |
13:34:51.51 |
+33:41:52.0 |
HIP 66128 |
18.65 |
| 2026-02-14 12:00 |
13:34:39.95 |
+33:45:02.3 |
HIP 66128 |
17.03 |
| 2026-02-15 00:00 |
13:34:28.10 |
+33:48:12.2 |
HIP 66128 |
16.18 |
| 2026-02-15 12:00 |
13:34:15.96 |
+33:51:21.7 |
HIP 66145 |
15.46 |
| 2026-02-16 00:00 |
13:34:03.53 |
+33:54:30.7 |
HIP 66145 |
11.40 |
| 2026-02-16 12:00 |
13:33:50.81 |
+33:57:39.2 |
HIP 66145 |
7.32 |
| 2026-02-17 00:00 |
13:33:37.80 |
+34:00:47.2 |
HIP 66145 |
3.28 |
| 2026-02-17 12:00 |
13:33:24.50 |
+34:03:54.5 |
HIP 66145 |
1.50 |
| 2026-02-18 00:00 |
13:33:10.92 |
+34:07:01.2 |
HIP 66145 |
5.37 |
| 2026-02-18 12:00 |
13:32:57.06 |
+34:10:07.2 |
HIP 66145 |
9.55 |
| 2026-02-19 00:00 |
13:32:42.91 |
+34:13:12.5 |
HIP 66145 |
13.80 |
| 2026-02-19 12:00 |
13:32:28.48 |
+34:16:17.0 |
HIP 66145 |
18.07 |
| 2026-02-20 00:00 |
13:32:13.78 |
+34:19:20.7 |
HIP 66145 |
22.38 |
| 2026-02-20 12:00 |
13:31:58.79 |
+34:22:23.6 |
HIP 65898 |
19.66 |
| 2026-02-21 00:00 |
13:31:43.53 |
+34:25:25.5 |
HIP 65898 |
15.71 |
| 2026-02-21 12:00 |
13:31:28.00 |
+34:28:26.6 |
HIP 65898 |
12.00 |
| 2026-02-22 00:00 |
13:31:12.20 |
+34:31:26.6 |
HIP 65898 |
8.89 |
| 2026-02-22 12:00 |
13:30:56.13 |
+34:34:25.7 |
HIP 65898 |
7.25 |
| 2026-02-23 00:00 |
13:30:39.79 |
+34:37:23.6 |
HIP 65898 |
8.08 |
| 2026-02-23 12:00 |
13:30:23.19 |
+34:40:20.5 |
HIP 65853 |
10.49 |
| 2026-02-24 00:00 |
13:30:06.32 |
+34:43:16.3 |
HIP 65853 |
12.00 |