メタデータ
| 項目 |
値 |
| Designation |
C/2021 R2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-12-25T00:02:41.040960Z |
| Orbit solution date (soln_date, UTC) |
2022-12-08T23:43:01Z |
| Obs used |
126 |
| NEO |
- |
| M1 |
7.000 |
| K1 |
10.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-09-05T08:07:54.134400Z |
| Discovery magnitude (MPC) |
20.48 w |
| Discovery observatory (MPC) |
F52 · Pan-STARRS 2, Haleakala |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2021-11-08.0000000 |
| e |
0.99748693 |
| q (au) |
7.311968 |
| a (au) |
2909.581318 |
| i (deg) |
134.470894 |
| Ω (om, deg) |
16.283615 |
| ω (w, deg) |
32.298315 |
| M (ma, deg) |
359.999705 |
等級
散乱 + 全体線形
$$
M_a = (2.347 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
2.347 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
17:01:07.97 |
+20:49:45.1 |
HIP 83162 |
19.59 |
| 2026-07-29 12:00 |
17:00:58.32 |
+20:48:20.5 |
HIP 83162 |
17.45 |
| 2026-07-30 00:00 |
17:00:48.74 |
+20:46:55.4 |
HIP 83162 |
15.49 |
| 2026-07-30 12:00 |
17:00:39.25 |
+20:45:29.7 |
HIP 83162 |
13.79 |
| 2026-07-31 00:00 |
17:00:29.85 |
+20:44:03.6 |
HIP 83162 |
12.43 |
| 2026-07-31 12:00 |
17:00:20.52 |
+20:42:36.9 |
HIP 83162 |
11.54 |
| 2026-08-01 00:00 |
17:00:11.28 |
+20:41:09.6 |
HIP 83162 |
11.22 |
| 2026-08-01 12:00 |
17:00:02.12 |
+20:39:41.9 |
HIP 83162 |
11.52 |
| 2026-08-02 00:00 |
16:59:53.05 |
+20:38:13.6 |
HIP 83162 |
12.37 |
| 2026-08-02 12:00 |
16:59:44.05 |
+20:36:44.9 |
HIP 83162 |
13.67 |
| 2026-08-03 00:00 |
16:59:35.15 |
+20:35:15.7 |
HIP 83162 |
15.31 |
| 2026-08-03 12:00 |
16:59:26.32 |
+20:33:46.0 |
HIP 83162 |
17.17 |
| 2026-08-04 00:00 |
16:59:17.59 |
+20:32:15.8 |
HIP 83162 |
19.19 |
| 2026-08-04 12:00 |
16:59:08.93 |
+20:30:45.1 |
HIP 83162 |
21.33 |
| 2026-08-05 00:00 |
16:59:00.37 |
+20:29:14.0 |
HIP 83068 |
22.15 |
| 2026-08-05 12:00 |
16:58:51.89 |
+20:27:42.4 |
HIP 83068 |
20.03 |
| 2026-08-06 00:00 |
16:58:43.49 |
+20:26:10.4 |
HIP 83068 |
18.00 |
| 2026-08-06 12:00 |
16:58:35.18 |
+20:24:37.9 |
HIP 83068 |
16.10 |
| 2026-08-07 00:00 |
16:58:26.96 |
+20:23:05.0 |
HIP 83068 |
14.38 |
| 2026-08-07 12:00 |
16:58:18.83 |
+20:21:31.7 |
HIP 83068 |
12.89 |
| 2026-08-08 00:00 |
16:58:10.78 |
+20:19:58.0 |
HIP 83068 |
11.72 |
| 2026-08-08 12:00 |
16:58:02.82 |
+20:18:23.8 |
HIP 83068 |
10.97 |
| 2026-08-09 00:00 |
16:57:54.95 |
+20:16:49.2 |
HIP 83068 |
10.71 |
| 2026-08-09 12:00 |
16:57:47.17 |
+20:15:14.3 |
HIP 83068 |
10.98 |
| 2026-08-10 00:00 |
16:57:39.48 |
+20:13:38.9 |
HIP 83068 |
11.72 |
| 2026-08-10 12:00 |
16:57:31.87 |
+20:12:03.2 |
HIP 83004 |
12.72 |
| 2026-08-11 00:00 |
16:57:24.36 |
+20:10:27.1 |
HIP 83004 |
11.64 |
| 2026-08-11 12:00 |
16:57:16.93 |
+20:08:50.7 |
HIP 83004 |
10.98 |
| 2026-08-12 00:00 |
16:57:09.59 |
+20:07:13.8 |
HIP 83004 |
10.78 |
| 2026-08-12 12:00 |
16:57:02.35 |
+20:05:36.7 |
HIP 83004 |
11.08 |
| 2026-08-13 00:00 |
16:56:55.19 |
+20:03:59.2 |
HIP 83004 |
11.82 |
| 2026-08-13 12:00 |
16:56:48.12 |
+20:02:21.3 |
HIP 83004 |
12.93 |
| 2026-08-14 00:00 |
16:56:41.15 |
+20:00:43.2 |
HIP 83004 |
14.31 |
| 2026-08-14 12:00 |
16:56:34.26 |
+19:59:04.7 |
HIP 83004 |
15.89 |
| 2026-08-15 00:00 |
16:56:27.47 |
+19:57:25.9 |
HIP 83004 |
17.61 |
| 2026-08-15 12:00 |
16:56:20.76 |
+19:55:46.8 |
HIP 83004 |
19.42 |
| 2026-08-16 00:00 |
16:56:14.15 |
+19:54:07.5 |
HIP 83004 |
21.31 |
| 2026-08-16 12:00 |
16:56:07.63 |
+19:52:27.8 |
HIP 83004 |
23.25 |
| 2026-08-17 00:00 |
16:56:01.20 |
+19:50:47.9 |
HIP 83004 |
25.23 |
| 2026-08-17 12:00 |
16:55:54.86 |
+19:49:07.7 |
HIP 83004 |
27.23 |
| 2026-08-18 00:00 |
16:55:48.61 |
+19:47:27.2 |
HIP 83004 |
29.24 |
| 2026-08-18 12:00 |
16:55:42.45 |
+19:45:46.5 |
HIP 83004 |
31.27 |
| 2026-08-19 00:00 |
16:55:36.38 |
+19:44:05.6 |
HIP 83004 |
33.31 |