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) |
| 2026-05-12 00:00 |
08:15:04.79 |
+20:46:54.6 |
HIP 40361 |
9.88 |
| 2026-05-12 12:00 |
08:15:15.99 |
+20:46:11.0 |
HIP 40471 |
7.89 |
| 2026-05-13 00:00 |
08:15:27.35 |
+20:45:27.0 |
HIP 40471 |
5.15 |
| 2026-05-13 12:00 |
08:15:38.87 |
+20:44:42.4 |
HIP 40471 |
2.41 |
| 2026-05-14 00:00 |
08:15:50.53 |
+20:43:57.4 |
HIP 40471 |
0.85 |
| 2026-05-14 12:00 |
08:16:02.35 |
+20:43:11.8 |
HIP 40471 |
3.45 |
| 2026-05-15 00:00 |
08:16:14.32 |
+20:42:25.8 |
HIP 40471 |
6.32 |
| 2026-05-15 12:00 |
08:16:26.44 |
+20:41:39.3 |
HIP 40471 |
9.24 |
| 2026-05-16 00:00 |
08:16:38.70 |
+20:40:52.2 |
HIP 40471 |
12.21 |
| 2026-05-16 12:00 |
08:16:51.11 |
+20:40:04.8 |
HIP 40471 |
15.22 |
| 2026-05-17 00:00 |
08:17:03.67 |
+20:39:16.8 |
HIP 40471 |
18.26 |
| 2026-05-17 12:00 |
08:17:16.37 |
+20:38:28.3 |
HIP 40471 |
21.33 |
| 2026-05-18 00:00 |
08:17:29.21 |
+20:37:39.4 |
HIP 40471 |
24.44 |
| 2026-05-18 12:00 |
08:17:42.19 |
+20:36:50.0 |
HIP 40471 |
27.59 |
| 2026-05-19 00:00 |
08:17:55.31 |
+20:36:00.2 |
HIP 40813 |
30.40 |
| 2026-05-19 12:00 |
08:18:08.56 |
+20:35:09.9 |
HIP 40813 |
27.33 |
| 2026-05-20 00:00 |
08:18:21.95 |
+20:34:19.1 |
HIP 40813 |
24.26 |
| 2026-05-20 12:00 |
08:18:35.48 |
+20:33:27.8 |
HIP 40813 |
21.22 |
| 2026-05-21 00:00 |
08:18:49.13 |
+20:32:36.1 |
HIP 40813 |
18.23 |
| 2026-05-21 12:00 |
08:19:02.92 |
+20:31:44.0 |
HIP 40813 |
15.35 |
| 2026-05-22 00:00 |
08:19:16.83 |
+20:30:51.4 |
HIP 40813 |
12.68 |
| 2026-05-22 12:00 |
08:19:30.88 |
+20:29:58.3 |
HIP 40813 |
10.40 |
| 2026-05-23 00:00 |
08:19:45.04 |
+20:29:04.8 |
HIP 40813 |
8.87 |
| 2026-05-23 12:00 |
08:19:59.34 |
+20:28:10.9 |
HIP 40813 |
8.54 |
| 2026-05-24 00:00 |
08:20:13.75 |
+20:27:16.5 |
HIP 40813 |
9.56 |
| 2026-05-24 12:00 |
08:20:28.29 |
+20:26:21.7 |
HIP 40813 |
11.61 |
| 2026-05-25 00:00 |
08:20:42.95 |
+20:25:26.5 |
HIP 40813 |
14.28 |
| 2026-05-25 12:00 |
08:20:57.72 |
+20:24:30.8 |
HIP 40813 |
17.30 |
| 2026-05-26 00:00 |
08:21:12.61 |
+20:23:34.7 |
HIP 40813 |
20.52 |
| 2026-05-26 12:00 |
08:21:27.62 |
+20:22:38.2 |
HIP 41083 |
23.80 |
| 2026-05-27 00:00 |
08:21:42.74 |
+20:21:41.2 |
HIP 41083 |
21.32 |
| 2026-05-27 12:00 |
08:21:57.98 |
+20:20:43.9 |
HIP 41083 |
19.20 |
| 2026-05-28 00:00 |
08:22:13.33 |
+20:19:46.1 |
HIP 41083 |
17.60 |
| 2026-05-28 12:00 |
08:22:28.79 |
+20:18:47.9 |
HIP 41083 |
16.69 |
| 2026-05-29 00:00 |
08:22:44.35 |
+20:17:49.3 |
HIP 41083 |
16.59 |
| 2026-05-29 12:00 |
08:23:00.03 |
+20:16:50.3 |
HIP 41098 |
15.77 |
| 2026-05-30 00:00 |
08:23:15.81 |
+20:15:50.8 |
HIP 41098 |
15.02 |
| 2026-05-30 12:00 |
08:23:31.70 |
+20:14:51.0 |
HIP 41098 |
15.24 |
| 2026-05-31 00:00 |
08:23:47.69 |
+20:13:50.7 |
HIP 41232 |
15.16 |
| 2026-05-31 12:00 |
08:24:03.79 |
+20:12:50.1 |
HIP 41232 |
11.26 |
| 2026-06-01 00:00 |
08:24:19.99 |
+20:11:49.1 |
HIP 41232 |
7.34 |
| 2026-06-01 12:00 |
08:24:36.29 |
+20:10:47.6 |
HIP 41232 |
3.43 |
| 2026-06-02 00:00 |
08:24:52.69 |
+20:09:45.8 |
HIP 41232 |
1.01 |