238P/Read
メタデータ
| 項目 |
値 |
| Designation |
238P/Read |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2022-06-05T10:21:50.189760Z |
| Orbit solution date (soln_date, UTC) |
2024-05-30T15:51:09Z |
| Obs used |
119 |
| NEO |
- |
| M1 |
8.300 |
| K1 |
29.750 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2022-09-15.0000000 |
| e |
0.25167358 |
| q (au) |
2.369349 |
| a (au) |
3.166197 |
| i (deg) |
1.264088 |
| Ω (om, deg) |
51.625454 |
| ω (w, deg) |
324.206807 |
| M (ma, deg) |
17.768666 |
等級
散乱 + 全体線形
$$
M_a = (13.654 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.654 |
| n |
6.000 |
| gf |
0.972 |
| gb |
-0.872 |
| k |
1.000 |
| δ90 |
8.980 |
| 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 |
| 2021-06-11 |
2021-11-26 |
+2.0364 |
+0.529 |
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 |
16:12:09.48 |
-21:06:30.9 |
HIP 79369 |
3.26 |
| 2026-02-03 12:00 |
16:12:35.73 |
-21:07:42.6 |
HIP 79369 |
9.48 |
| 2026-02-04 00:00 |
16:13:01.84 |
-21:08:53.8 |
HIP 79369 |
15.68 |
| 2026-02-04 12:00 |
16:13:27.81 |
-21:10:04.3 |
HIP 79524 |
14.23 |
| 2026-02-05 00:00 |
16:13:53.62 |
-21:11:14.2 |
HIP 79599 |
9.51 |
| 2026-02-05 12:00 |
16:14:19.29 |
-21:12:23.5 |
HIP 79599 |
6.35 |
| 2026-02-06 00:00 |
16:14:44.82 |
-21:13:32.1 |
HIP 79599 |
8.00 |
| 2026-02-06 12:00 |
16:15:10.19 |
-21:14:40.2 |
HIP 79599 |
12.66 |
| 2026-02-07 00:00 |
16:15:35.41 |
-21:15:47.6 |
HIP 79743 |
12.52 |
| 2026-02-07 12:00 |
16:16:00.47 |
-21:16:54.5 |
HIP 79743 |
7.11 |
| 2026-02-08 00:00 |
16:16:25.38 |
-21:18:00.7 |
HIP 79743 |
3.86 |
| 2026-02-08 12:00 |
16:16:50.13 |
-21:19:06.3 |
HIP 79785 |
2.19 |
| 2026-02-09 00:00 |
16:17:14.73 |
-21:20:11.3 |
HIP 79785 |
4.19 |
| 2026-02-09 12:00 |
16:17:39.16 |
-21:21:15.6 |
HIP 79785 |
9.88 |
| 2026-02-10 00:00 |
16:18:03.44 |
-21:22:19.4 |
HIP 79785 |
15.60 |
| 2026-02-10 12:00 |
16:18:27.55 |
-21:23:22.6 |
HIP 79910 |
12.49 |
| 2026-02-11 00:00 |
16:18:51.49 |
-21:24:25.1 |
HIP 79977 |
8.79 |
| 2026-02-11 12:00 |
16:19:15.27 |
-21:25:27.1 |
HIP 79977 |
3.48 |
| 2026-02-12 00:00 |
16:19:38.88 |
-21:26:28.4 |
HIP 79977 |
3.18 |
| 2026-02-12 12:00 |
16:20:02.32 |
-21:27:29.2 |
HIP 80059 |
6.74 |
| 2026-02-13 00:00 |
16:20:25.59 |
-21:28:29.3 |
HIP 80059 |
2.13 |
| 2026-02-13 12:00 |
16:20:48.68 |
-21:29:28.8 |
HIP 80059 |
4.89 |
| 2026-02-14 00:00 |
16:21:11.60 |
-21:30:27.7 |
HIP 80059 |
10.11 |
| 2026-02-14 12:00 |
16:21:34.35 |
-21:31:26.1 |
HIP 80169 |
5.55 |
| 2026-02-15 00:00 |
16:21:56.91 |
-21:32:23.8 |
HIP 80169 |
3.73 |
| 2026-02-15 12:00 |
16:22:19.30 |
-21:33:20.9 |
HIP 80169 |
7.31 |
| 2026-02-16 00:00 |
16:22:41.50 |
-21:34:17.4 |
HIP 80169 |
12.16 |
| 2026-02-16 12:00 |
16:23:03.52 |
-21:35:13.4 |
HIP 80169 |
17.20 |
| 2026-02-17 00:00 |
16:23:25.36 |
-21:36:08.7 |
HIP 80276 |
19.43 |
| 2026-02-17 12:00 |
16:23:47.01 |
-21:37:03.4 |
HIP 80276 |
21.72 |
| 2026-02-18 00:00 |
16:24:08.47 |
-21:37:57.6 |
HIP 80458 |
17.89 |
| 2026-02-18 12:00 |
16:24:29.75 |
-21:38:51.1 |
HIP 80458 |
12.87 |
| 2026-02-19 00:00 |
16:24:50.83 |
-21:39:44.1 |
HIP 80458 |
7.89 |
| 2026-02-19 12:00 |
16:25:11.72 |
-21:40:36.5 |
HIP 80458 |
2.96 |
| 2026-02-20 00:00 |
16:25:32.41 |
-21:41:28.3 |
HIP 80458 |
1.93 |
| 2026-02-20 12:00 |
16:25:52.91 |
-21:42:19.5 |
HIP 80458 |
6.77 |
| 2026-02-21 00:00 |
16:26:13.21 |
-21:43:10.1 |
HIP 80534 |
5.91 |
| 2026-02-21 12:00 |
16:26:33.31 |
-21:44:00.2 |
HIP 80534 |
3.76 |
| 2026-02-22 00:00 |
16:26:53.22 |
-21:44:49.6 |
HIP 80534 |
6.15 |
| 2026-02-22 12:00 |
16:27:12.92 |
-21:45:38.5 |
HIP 80534 |
10.23 |
| 2026-02-23 00:00 |
16:27:32.41 |
-21:46:26.8 |
HIP 80534 |
14.61 |
| 2026-02-23 12:00 |
16:27:51.71 |
-21:47:14.6 |
HIP 80534 |
19.04 |
| 2026-02-24 00:00 |
16:28:10.79 |
-21:48:01.7 |
HIP 80756 |
21.19 |