メタデータ
| 項目 |
値 |
| Designation |
P/2021 R4 (Wierzchos) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-10-13T22:05:15.889920Z |
| Orbit solution date (soln_date, UTC) |
2021-11-20T19:13:09Z |
| Obs used |
76 |
| NEO |
- |
| M1 |
16.300 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-09-06T09:39:32.976000Z |
| Discovery magnitude (MPC) |
21.16 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2021-09-24.0000000 |
| e |
0.58615107 |
| q (au) |
2.325993 |
| a (au) |
5.620391 |
| i (deg) |
21.040112 |
| Ω (om, deg) |
321.256290 |
| ω (w, deg) |
56.624470 |
| M (ma, deg) |
358.526498 |
等級
散乱 + 全体線形
$$
M_a = (15.933 + 3.415\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
15.933 |
| n |
3.415 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
11:40:29.35 |
-11:12:32.9 |
HIP 56798 |
27.32 |
| 2026-09-20 12:00 |
11:40:43.20 |
-11:14:15.1 |
HIP 57105 |
30.10 |
| 2026-09-21 00:00 |
11:40:57.05 |
-11:15:57.5 |
HIP 57105 |
26.33 |
| 2026-09-21 12:00 |
11:41:10.89 |
-11:17:40.2 |
HIP 57105 |
22.58 |
| 2026-09-22 00:00 |
11:41:24.72 |
-11:19:23.2 |
HIP 57105 |
18.84 |
| 2026-09-22 12:00 |
11:41:38.55 |
-11:21:06.4 |
HIP 57105 |
15.14 |
| 2026-09-23 00:00 |
11:41:52.37 |
-11:22:49.9 |
HIP 57105 |
11.49 |
| 2026-09-23 12:00 |
11:42:06.18 |
-11:24:33.7 |
HIP 57105 |
7.99 |
| 2026-09-24 00:00 |
11:42:19.98 |
-11:26:17.7 |
HIP 57105 |
4.94 |
| 2026-09-24 12:00 |
11:42:33.78 |
-11:28:01.9 |
HIP 57105 |
3.72 |
| 2026-09-25 00:00 |
11:42:47.57 |
-11:29:46.4 |
HIP 57105 |
5.67 |
| 2026-09-25 12:00 |
11:43:01.34 |
-11:31:31.2 |
HIP 57105 |
8.91 |
| 2026-09-26 00:00 |
11:43:15.11 |
-11:33:16.2 |
HIP 57105 |
12.46 |
| 2026-09-26 12:00 |
11:43:28.87 |
-11:35:01.5 |
HIP 57105 |
16.13 |
| 2026-09-27 00:00 |
11:43:42.62 |
-11:36:47.0 |
HIP 57281 |
17.47 |
| 2026-09-27 12:00 |
11:43:56.35 |
-11:38:32.7 |
HIP 57281 |
15.71 |
| 2026-09-28 00:00 |
11:44:10.08 |
-11:40:18.6 |
HIP 57281 |
14.75 |
| 2026-09-28 12:00 |
11:44:23.79 |
-11:42:04.8 |
HIP 57281 |
14.74 |
| 2026-09-29 00:00 |
11:44:37.48 |
-11:43:51.3 |
HIP 57281 |
15.69 |
| 2026-09-29 12:00 |
11:44:51.17 |
-11:45:37.9 |
HIP 57281 |
17.43 |
| 2026-09-30 00:00 |
11:45:04.84 |
-11:47:24.8 |
HIP 57281 |
19.75 |
| 2026-09-30 12:00 |
11:45:18.50 |
-11:49:11.8 |
HIP 57414 |
18.48 |
| 2026-10-01 00:00 |
11:45:32.14 |
-11:50:59.1 |
HIP 57414 |
14.83 |
| 2026-10-01 12:00 |
11:45:45.76 |
-11:52:46.6 |
HIP 57414 |
11.27 |
| 2026-10-02 00:00 |
11:45:59.37 |
-11:54:34.4 |
HIP 57414 |
7.91 |
| 2026-10-02 12:00 |
11:46:12.97 |
-11:56:22.3 |
HIP 57414 |
5.17 |
| 2026-10-03 00:00 |
11:46:26.54 |
-11:58:10.4 |
HIP 57414 |
4.41 |
| 2026-10-03 12:00 |
11:46:40.10 |
-11:59:58.7 |
HIP 57414 |
6.37 |
| 2026-10-04 00:00 |
11:46:53.64 |
-12:01:47.2 |
HIP 57414 |
9.50 |
| 2026-10-04 12:00 |
11:47:07.16 |
-12:03:36.0 |
HIP 57414 |
12.97 |
| 2026-10-05 00:00 |
11:47:20.67 |
-12:05:24.9 |
HIP 57494 |
16.49 |
| 2026-10-05 12:00 |
11:47:34.15 |
-12:07:13.9 |
HIP 57494 |
19.27 |
| 2026-10-06 00:00 |
11:47:47.61 |
-12:09:03.2 |
HIP 57494 |
22.34 |
| 2026-10-06 12:00 |
11:48:01.05 |
-12:10:52.7 |
HIP 57494 |
25.59 |
| 2026-10-07 00:00 |
11:48:14.47 |
-12:12:42.3 |
HIP 57634 |
27.13 |
| 2026-10-07 12:00 |
11:48:27.86 |
-12:14:32.1 |
HIP 57634 |
24.11 |
| 2026-10-08 00:00 |
11:48:41.24 |
-12:16:22.0 |
HIP 57634 |
21.32 |
| 2026-10-08 12:00 |
11:48:54.59 |
-12:18:12.2 |
HIP 57634 |
18.86 |
| 2026-10-09 00:00 |
11:49:07.91 |
-12:20:02.4 |
HIP 57634 |
16.88 |
| 2026-10-09 12:00 |
11:49:21.21 |
-12:21:52.9 |
HIP 57634 |
15.55 |
| 2026-10-10 00:00 |
11:49:34.49 |
-12:23:43.4 |
HIP 57634 |
15.05 |
| 2026-10-10 12:00 |
11:49:47.73 |
-12:25:34.2 |
HIP 57634 |
15.45 |
| 2026-10-11 00:00 |
11:50:00.96 |
-12:27:25.0 |
HIP 57634 |
16.68 |