メタデータ
| 項目 |
値 |
| Designation |
125P/Spacewatch |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2013-02-17T02:03:36.748800Z |
| Orbit solution date (soln_date, UTC) |
2024-10-29T14:53:15Z |
| Obs used |
1297 |
| NEO |
- |
| M1 |
12.900 |
| K1 |
16.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2015-08-11.0000000 |
| e |
0.51269168 |
| q (au) |
1.523187 |
| a (au) |
3.125715 |
| i (deg) |
9.988031 |
| Ω (om, deg) |
153.195189 |
| ω (w, deg) |
87.145345 |
| M (ma, deg) |
161.393997 |
等級
散乱 + 全体線形
$$
M_a = (12.400 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.400 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.850 |
| k |
0.999 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
04:25:02.65 |
+10:35:43.3 |
HIP 20481 |
28.03 |
| 2026-09-20 12:00 |
04:25:01.83 |
+10:34:29.2 |
HIP 20481 |
28.47 |
| 2026-09-21 00:00 |
04:25:00.79 |
+10:33:14.7 |
HIP 20481 |
28.92 |
| 2026-09-21 12:00 |
04:24:59.53 |
+10:31:59.6 |
HIP 20481 |
29.38 |
| 2026-09-22 00:00 |
04:24:58.04 |
+10:30:44.0 |
HIP 20597 |
28.20 |
| 2026-09-22 12:00 |
04:24:56.33 |
+10:29:27.8 |
HIP 20597 |
26.89 |
| 2026-09-23 00:00 |
04:24:54.38 |
+10:28:11.2 |
HIP 20597 |
25.56 |
| 2026-09-23 12:00 |
04:24:52.22 |
+10:26:54.0 |
HIP 20597 |
24.22 |
| 2026-09-24 00:00 |
04:24:49.82 |
+10:25:36.3 |
HIP 20597 |
22.88 |
| 2026-09-24 12:00 |
04:24:47.20 |
+10:24:18.2 |
HIP 20597 |
21.53 |
| 2026-09-25 00:00 |
04:24:44.36 |
+10:22:59.5 |
HIP 20597 |
20.19 |
| 2026-09-25 12:00 |
04:24:41.28 |
+10:21:40.3 |
HIP 20597 |
18.87 |
| 2026-09-26 00:00 |
04:24:37.98 |
+10:20:20.7 |
HIP 20597 |
17.57 |
| 2026-09-26 12:00 |
04:24:34.45 |
+10:19:00.6 |
HIP 20597 |
16.31 |
| 2026-09-27 00:00 |
04:24:30.69 |
+10:17:40.0 |
HIP 20597 |
15.12 |
| 2026-09-27 12:00 |
04:24:26.71 |
+10:16:18.9 |
HIP 20597 |
14.02 |
| 2026-09-28 00:00 |
04:24:22.49 |
+10:14:57.4 |
HIP 20597 |
13.06 |
| 2026-09-28 12:00 |
04:24:18.05 |
+10:13:35.4 |
HIP 20597 |
12.29 |
| 2026-09-29 00:00 |
04:24:13.38 |
+10:12:13.0 |
HIP 20597 |
11.75 |
| 2026-09-29 12:00 |
04:24:08.48 |
+10:10:50.1 |
HIP 20597 |
11.51 |
| 2026-09-30 00:00 |
04:24:03.35 |
+10:09:26.8 |
HIP 20597 |
11.60 |
| 2026-09-30 12:00 |
04:23:58.00 |
+10:08:03.1 |
HIP 20597 |
12.03 |
| 2026-10-01 00:00 |
04:23:52.41 |
+10:06:38.9 |
HIP 20597 |
12.80 |
| 2026-10-01 12:00 |
04:23:46.60 |
+10:05:14.4 |
HIP 20597 |
13.85 |
| 2026-10-02 00:00 |
04:23:40.55 |
+10:03:49.4 |
HIP 20597 |
15.16 |
| 2026-10-02 12:00 |
04:23:34.28 |
+10:02:24.0 |
HIP 20597 |
16.68 |
| 2026-10-03 00:00 |
04:23:27.78 |
+10:00:58.2 |
HIP 20447 |
17.26 |
| 2026-10-03 12:00 |
04:23:21.05 |
+09:59:32.1 |
HIP 20447 |
15.18 |
| 2026-10-04 00:00 |
04:23:14.09 |
+09:58:05.5 |
HIP 20447 |
13.11 |
| 2026-10-04 12:00 |
04:23:06.90 |
+09:56:38.6 |
HIP 20447 |
11.08 |
| 2026-10-05 00:00 |
04:22:59.48 |
+09:55:11.4 |
HIP 20447 |
9.15 |
| 2026-10-05 12:00 |
04:22:51.83 |
+09:53:43.7 |
HIP 20447 |
7.44 |
| 2026-10-06 00:00 |
04:22:43.96 |
+09:52:15.8 |
HIP 20447 |
6.22 |
| 2026-10-06 12:00 |
04:22:35.85 |
+09:50:47.5 |
HIP 20447 |
5.84 |
| 2026-10-07 00:00 |
04:22:27.52 |
+09:49:18.8 |
HIP 20447 |
6.52 |
| 2026-10-07 12:00 |
04:22:18.97 |
+09:47:49.9 |
HIP 20447 |
8.03 |
| 2026-10-08 00:00 |
04:22:10.19 |
+09:46:20.6 |
HIP 20447 |
10.04 |
| 2026-10-08 12:00 |
04:22:01.18 |
+09:44:51.1 |
HIP 20447 |
12.35 |
| 2026-10-09 00:00 |
04:21:51.94 |
+09:43:21.2 |
HIP 20447 |
14.83 |
| 2026-10-09 12:00 |
04:21:42.49 |
+09:41:51.1 |
HIP 20447 |
17.44 |
| 2026-10-10 00:00 |
04:21:32.80 |
+09:40:20.8 |
HIP 20447 |
20.15 |
| 2026-10-10 12:00 |
04:21:22.90 |
+09:38:50.1 |
HIP 20447 |
22.94 |
| 2026-10-11 00:00 |
04:21:12.77 |
+09:37:19.2 |
HIP 20281 |
24.54 |