メタデータ
| 項目 |
値 |
| Designation |
323P/SOHO |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-01-17T15:09:04.803840Z |
| Orbit solution date (soln_date, UTC) |
2025-02-20T14:38:09Z |
| Obs used |
171 |
| NEO |
Yes |
| M1 |
23.400 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2021-03-03.0000000 |
| e |
0.98481410 |
| q (au) |
0.039207 |
| a (au) |
2.581828 |
| i (deg) |
5.369972 |
| Ω (om, deg) |
324.229171 |
| ω (w, deg) |
353.174495 |
| M (ma, deg) |
10.541190 |
等級
散乱 + 全体線形
$$
M_a = (20.000 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
20.000 |
| n |
6.000 |
| 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 |
| 2025-01-27 |
2025-02-08 |
-17.3579 |
+3.208 |
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 |
09:02:40.48 |
+17:37:34.5 |
HIP 44432 |
7.46 |
| 2026-07-29 12:00 |
09:03:01.90 |
+17:36:01.5 |
HIP 44432 |
2.30 |
| 2026-07-30 00:00 |
09:03:23.32 |
+17:34:28.3 |
HIP 44432 |
3.44 |
| 2026-07-30 12:00 |
09:03:44.73 |
+17:32:55.1 |
HIP 44432 |
8.68 |
| 2026-07-31 00:00 |
09:04:06.13 |
+17:31:21.7 |
HIP 44432 |
13.99 |
| 2026-07-31 12:00 |
09:04:27.54 |
+17:29:48.2 |
HIP 44432 |
19.31 |
| 2026-08-01 00:00 |
09:04:48.93 |
+17:28:14.6 |
HIP 44637 |
14.34 |
| 2026-08-01 12:00 |
09:05:10.32 |
+17:26:40.9 |
HIP 44637 |
9.02 |
| 2026-08-02 00:00 |
09:05:31.71 |
+17:25:07.1 |
HIP 44637 |
3.72 |
| 2026-08-02 12:00 |
09:05:53.08 |
+17:23:33.1 |
HIP 44637 |
1.80 |
| 2026-08-03 00:00 |
09:06:14.45 |
+17:21:59.1 |
HIP 44637 |
7.04 |
| 2026-08-03 12:00 |
09:06:35.81 |
+17:20:25.0 |
HIP 44637 |
12.36 |
| 2026-08-04 00:00 |
09:06:57.16 |
+17:18:50.8 |
HIP 44674 |
15.67 |
| 2026-08-04 12:00 |
09:07:18.50 |
+17:17:16.5 |
HIP 44674 |
18.36 |
| 2026-08-05 00:00 |
09:07:39.83 |
+17:15:42.1 |
HIP 44908 |
17.88 |
| 2026-08-05 12:00 |
09:08:01.14 |
+17:14:07.6 |
HIP 44908 |
12.71 |
| 2026-08-06 00:00 |
09:08:22.45 |
+17:12:33.1 |
HIP 44908 |
7.78 |
| 2026-08-06 12:00 |
09:08:43.74 |
+17:10:58.5 |
HIP 44908 |
4.00 |
| 2026-08-07 00:00 |
09:09:05.03 |
+17:09:23.7 |
HIP 44908 |
5.31 |
| 2026-08-07 12:00 |
09:09:26.29 |
+17:07:49.0 |
HIP 44908 |
9.85 |
| 2026-08-08 00:00 |
09:09:47.54 |
+17:06:14.1 |
HIP 44908 |
14.91 |
| 2026-08-08 12:00 |
09:10:08.78 |
+17:04:39.2 |
HIP 44908 |
20.11 |
| 2026-08-09 00:00 |
09:10:30.00 |
+17:03:04.2 |
HIP 44908 |
25.35 |
| 2026-08-09 12:00 |
09:10:51.21 |
+17:01:29.2 |
HIP 44908 |
30.61 |
| 2026-08-10 00:00 |
09:11:12.39 |
+16:59:54.1 |
HIP 45209 |
31.73 |
| 2026-08-10 12:00 |
09:11:33.56 |
+16:58:19.0 |
HIP 45209 |
27.09 |
| 2026-08-11 00:00 |
09:11:54.71 |
+16:56:43.8 |
HIP 45209 |
22.75 |
| 2026-08-11 12:00 |
09:12:15.84 |
+16:55:08.6 |
HIP 45209 |
18.92 |
| 2026-08-12 00:00 |
09:12:36.95 |
+16:53:33.3 |
HIP 45209 |
15.94 |
| 2026-08-12 12:00 |
09:12:58.03 |
+16:51:58.1 |
HIP 45209 |
14.37 |
| 2026-08-13 00:00 |
09:13:19.10 |
+16:50:22.7 |
HIP 45209 |
14.65 |
| 2026-08-13 12:00 |
09:13:40.14 |
+16:48:47.4 |
HIP 45209 |
16.69 |
| 2026-08-14 00:00 |
09:14:01.16 |
+16:47:12.1 |
HIP 45209 |
19.96 |
| 2026-08-14 12:00 |
09:14:22.15 |
+16:45:36.7 |
HIP 45209 |
23.95 |
| 2026-08-15 00:00 |
09:14:43.12 |
+16:44:01.3 |
HIP 45209 |
28.35 |
| 2026-08-15 12:00 |
09:15:04.06 |
+16:42:25.9 |
HIP 45209 |
33.01 |
| 2026-08-16 00:00 |
09:15:24.97 |
+16:40:50.5 |
HIP 45579 |
29.12 |
| 2026-08-16 12:00 |
09:15:45.86 |
+16:39:15.2 |
HIP 45579 |
23.88 |
| 2026-08-17 00:00 |
09:16:06.71 |
+16:37:39.8 |
HIP 45579 |
18.64 |
| 2026-08-17 12:00 |
09:16:27.54 |
+16:36:04.4 |
HIP 45579 |
13.42 |
| 2026-08-18 00:00 |
09:16:48.34 |
+16:34:29.1 |
HIP 45579 |
8.22 |
| 2026-08-18 12:00 |
09:17:09.11 |
+16:32:53.7 |
HIP 45579 |
3.13 |
| 2026-08-19 00:00 |
09:17:29.84 |
+16:31:18.4 |
HIP 45579 |
2.56 |