メタデータ
| 項目 |
値 |
| Designation |
P/2021 R8 (Sheppard) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-10-07T12:21:16.145280Z |
| Orbit solution date (soln_date, UTC) |
2021-12-07T11:12:02Z |
| Obs used |
26 |
| NEO |
- |
| M1 |
18.600 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-09-05T13:08:45.772800Z |
| Discovery magnitude (MPC) |
21.69 G |
| Discovery observatory (MPC) |
T09 · Subaru Telescope, Maunakea |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2021-09-16.0000000 |
| e |
0.29404210 |
| q (au) |
2.130978 |
| a (au) |
3.018562 |
| i (deg) |
2.203054 |
| Ω (om, deg) |
167.025325 |
| ω (w, deg) |
190.793883 |
| M (ma, deg) |
355.956657 |
等級
散乱 + 全体線形
$$
M_a = (16.419 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
16.419 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.900 |
| 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
ファインディングチャート
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
20:38:22.12 |
-15:46:41.5 |
HIP 101999 |
35.95 |
| 2026-06-01 12:00 |
20:38:32.07 |
-15:45:47.3 |
HIP 101999 |
33.58 |
| 2026-06-02 00:00 |
20:38:41.66 |
-15:44:54.5 |
HIP 101999 |
31.32 |
| 2026-06-02 12:00 |
20:38:50.90 |
-15:44:03.1 |
HIP 101999 |
29.17 |
| 2026-06-03 00:00 |
20:38:59.78 |
-15:43:13.1 |
HIP 101999 |
27.14 |
| 2026-06-03 12:00 |
20:39:08.29 |
-15:42:24.5 |
HIP 101999 |
25.22 |
| 2026-06-04 00:00 |
20:39:16.44 |
-15:41:37.4 |
HIP 101999 |
23.42 |
| 2026-06-04 12:00 |
20:39:24.22 |
-15:40:51.8 |
HIP 101999 |
21.74 |
| 2026-06-05 00:00 |
20:39:31.64 |
-15:40:07.6 |
HIP 101999 |
20.19 |
| 2026-06-05 12:00 |
20:39:38.69 |
-15:39:24.9 |
HIP 101999 |
18.78 |
| 2026-06-06 00:00 |
20:39:45.36 |
-15:38:43.7 |
HIP 101999 |
17.50 |
| 2026-06-06 12:00 |
20:39:51.66 |
-15:38:04.1 |
HIP 101999 |
16.36 |
| 2026-06-07 00:00 |
20:39:57.59 |
-15:37:26.0 |
HIP 101999 |
15.36 |
| 2026-06-07 12:00 |
20:40:03.13 |
-15:36:49.4 |
HIP 101999 |
14.51 |
| 2026-06-08 00:00 |
20:40:08.30 |
-15:36:14.4 |
HIP 101999 |
13.78 |
| 2026-06-08 12:00 |
20:40:13.09 |
-15:35:41.0 |
HIP 101999 |
13.19 |
| 2026-06-09 00:00 |
20:40:17.50 |
-15:35:09.2 |
HIP 101999 |
12.71 |
| 2026-06-09 12:00 |
20:40:21.52 |
-15:34:39.0 |
HIP 101999 |
12.35 |
| 2026-06-10 00:00 |
20:40:25.15 |
-15:34:10.4 |
HIP 101999 |
12.07 |
| 2026-06-10 12:00 |
20:40:28.40 |
-15:33:43.4 |
HIP 101999 |
11.86 |
| 2026-06-11 00:00 |
20:40:31.27 |
-15:33:18.1 |
HIP 101999 |
11.71 |
| 2026-06-11 12:00 |
20:40:33.74 |
-15:32:54.4 |
HIP 101999 |
11.60 |
| 2026-06-12 00:00 |
20:40:35.82 |
-15:32:32.4 |
HIP 101999 |
11.51 |
| 2026-06-12 12:00 |
20:40:37.51 |
-15:32:12.0 |
HIP 101999 |
11.42 |
| 2026-06-13 00:00 |
20:40:38.80 |
-15:31:53.4 |
HIP 101999 |
11.33 |
| 2026-06-13 12:00 |
20:40:39.71 |
-15:31:36.5 |
HIP 101999 |
11.22 |
| 2026-06-14 00:00 |
20:40:40.21 |
-15:31:21.2 |
HIP 101999 |
11.09 |
| 2026-06-14 12:00 |
20:40:40.33 |
-15:31:07.7 |
HIP 101999 |
10.93 |
| 2026-06-15 00:00 |
20:40:40.04 |
-15:30:55.9 |
HIP 101999 |
10.73 |
| 2026-06-15 12:00 |
20:40:39.37 |
-15:30:45.9 |
HIP 101999 |
10.50 |
| 2026-06-16 00:00 |
20:40:38.29 |
-15:30:37.5 |
HIP 101999 |
10.23 |
| 2026-06-16 12:00 |
20:40:36.82 |
-15:30:30.9 |
HIP 101999 |
9.93 |
| 2026-06-17 00:00 |
20:40:34.96 |
-15:30:26.1 |
HIP 101999 |
9.61 |
| 2026-06-17 12:00 |
20:40:32.69 |
-15:30:23.0 |
HIP 101999 |
9.27 |
| 2026-06-18 00:00 |
20:40:30.04 |
-15:30:21.7 |
HIP 101999 |
8.93 |
| 2026-06-18 12:00 |
20:40:26.99 |
-15:30:22.1 |
HIP 101999 |
8.61 |
| 2026-06-19 00:00 |
20:40:23.54 |
-15:30:24.3 |
HIP 101999 |
8.34 |
| 2026-06-19 12:00 |
20:40:19.70 |
-15:30:28.2 |
HIP 101999 |
8.16 |
| 2026-06-20 00:00 |
20:40:15.46 |
-15:30:33.9 |
HIP 101999 |
8.10 |
| 2026-06-20 12:00 |
20:40:10.84 |
-15:30:41.3 |
HIP 101999 |
8.20 |
| 2026-06-21 00:00 |
20:40:05.82 |
-15:30:50.6 |
HIP 101999 |
8.50 |
| 2026-06-21 12:00 |
20:40:00.40 |
-15:31:01.5 |
HIP 101999 |
9.02 |
| 2026-06-22 00:00 |
20:39:54.60 |
-15:31:14.3 |
HIP 101999 |
9.75 |