メタデータ
| 項目 |
値 |
| Designation |
P/2021 HS (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-08-06T09:22:36.661440Z |
| Orbit solution date (soln_date, UTC) |
2021-12-17T03:12:57Z |
| Obs used |
181 |
| NEO |
Yes |
| M1 |
20.600 |
| 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) |
2021-07-03.0000000 |
| e |
0.81016790 |
| q (au) |
0.796446 |
| a (au) |
4.195528 |
| i (deg) |
12.171396 |
| Ω (om, deg) |
262.395858 |
| ω (w, deg) |
46.086196 |
| M (ma, deg) |
356.055743 |
等級
散乱 + 全体線形
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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) |
| 2026-03-26 00:00 |
08:14:47.01 |
+09:47:52.4 |
HIP 40449 |
15.35 |
| 2026-03-26 12:00 |
08:14:41.83 |
+09:48:41.7 |
HIP 40449 |
15.74 |
| 2026-03-27 00:00 |
08:14:36.80 |
+09:49:30.6 |
HIP 40449 |
16.25 |
| 2026-03-27 12:00 |
08:14:31.90 |
+09:50:19.2 |
HIP 40449 |
16.84 |
| 2026-03-28 00:00 |
08:14:27.14 |
+09:51:07.4 |
HIP 40449 |
17.50 |
| 2026-03-28 12:00 |
08:14:22.52 |
+09:51:55.2 |
HIP 40449 |
18.22 |
| 2026-03-29 00:00 |
08:14:18.04 |
+09:52:42.6 |
HIP 40372 |
18.90 |
| 2026-03-29 12:00 |
08:14:13.70 |
+09:53:29.6 |
HIP 40372 |
18.36 |
| 2026-03-30 00:00 |
08:14:09.50 |
+09:54:16.3 |
HIP 40372 |
17.90 |
| 2026-03-30 12:00 |
08:14:05.43 |
+09:55:02.6 |
HIP 40372 |
17.52 |
| 2026-03-31 00:00 |
08:14:01.51 |
+09:55:48.5 |
HIP 40372 |
17.21 |
| 2026-03-31 12:00 |
08:13:57.72 |
+09:56:34.0 |
HIP 40372 |
16.97 |
| 2026-04-01 00:00 |
08:13:54.08 |
+09:57:19.1 |
HIP 40372 |
16.81 |
| 2026-04-01 12:00 |
08:13:50.57 |
+09:58:03.7 |
HIP 40372 |
16.70 |
| 2026-04-02 00:00 |
08:13:47.20 |
+09:58:48.0 |
HIP 40372 |
16.66 |
| 2026-04-02 12:00 |
08:13:43.98 |
+09:59:31.9 |
HIP 40372 |
16.67 |
| 2026-04-03 00:00 |
08:13:40.89 |
+10:00:15.4 |
HIP 40372 |
16.73 |
| 2026-04-03 12:00 |
08:13:37.94 |
+10:00:58.5 |
HIP 40372 |
16.84 |
| 2026-04-04 00:00 |
08:13:35.13 |
+10:01:41.1 |
HIP 40372 |
16.98 |
| 2026-04-04 12:00 |
08:13:32.45 |
+10:02:23.4 |
HIP 40372 |
17.15 |
| 2026-04-05 00:00 |
08:13:29.92 |
+10:03:05.2 |
HIP 40372 |
17.34 |
| 2026-04-05 12:00 |
08:13:27.53 |
+10:03:46.6 |
HIP 40372 |
17.55 |
| 2026-04-06 00:00 |
08:13:25.27 |
+10:04:27.6 |
HIP 40372 |
17.78 |
| 2026-04-06 12:00 |
08:13:23.15 |
+10:05:08.1 |
HIP 40284 |
17.98 |
| 2026-04-07 00:00 |
08:13:21.18 |
+10:05:48.2 |
HIP 40284 |
17.42 |
| 2026-04-07 12:00 |
08:13:19.34 |
+10:06:27.9 |
HIP 40284 |
16.88 |
| 2026-04-08 00:00 |
08:13:17.63 |
+10:07:07.2 |
HIP 40284 |
16.36 |
| 2026-04-08 12:00 |
08:13:16.07 |
+10:07:46.0 |
HIP 40284 |
15.85 |
| 2026-04-09 00:00 |
08:13:14.65 |
+10:08:24.3 |
HIP 40284 |
15.36 |
| 2026-04-09 12:00 |
08:13:13.36 |
+10:09:02.3 |
HIP 40284 |
14.88 |
| 2026-04-10 00:00 |
08:13:12.21 |
+10:09:39.7 |
HIP 40284 |
14.42 |
| 2026-04-10 12:00 |
08:13:11.20 |
+10:10:16.8 |
HIP 40284 |
13.96 |
| 2026-04-11 00:00 |
08:13:10.32 |
+10:10:53.3 |
HIP 40284 |
13.51 |
| 2026-04-11 12:00 |
08:13:09.58 |
+10:11:29.5 |
HIP 40284 |
13.07 |
| 2026-04-12 00:00 |
08:13:08.98 |
+10:12:05.1 |
HIP 40284 |
12.64 |
| 2026-04-12 12:00 |
08:13:08.52 |
+10:12:40.4 |
HIP 40284 |
12.21 |
| 2026-04-13 00:00 |
08:13:08.20 |
+10:13:15.1 |
HIP 40284 |
11.77 |
| 2026-04-13 12:00 |
08:13:08.01 |
+10:13:49.4 |
HIP 40284 |
11.34 |
| 2026-04-14 00:00 |
08:13:07.95 |
+10:14:23.2 |
HIP 40284 |
10.91 |
| 2026-04-14 12:00 |
08:13:08.04 |
+10:14:56.6 |
HIP 40284 |
10.47 |
| 2026-04-15 00:00 |
08:13:08.25 |
+10:15:29.4 |
HIP 40284 |
10.02 |
| 2026-04-15 12:00 |
08:13:08.61 |
+10:16:01.9 |
HIP 40284 |
9.57 |
| 2026-04-16 00:00 |
08:13:09.10 |
+10:16:33.8 |
HIP 40284 |
9.12 |