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 |
0.997 |
| 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) |
| 2026-03-26 00:00 |
17:49:20.51 |
+19:39:43.5 |
HIP 87192 |
25.61 |
| 2026-03-26 12:00 |
17:49:15.65 |
+19:41:15.9 |
HIP 87192 |
26.78 |
| 2026-03-27 00:00 |
17:49:10.70 |
+19:42:48.2 |
HIP 87192 |
28.03 |
| 2026-03-27 12:00 |
17:49:05.65 |
+19:44:20.5 |
HIP 87222 |
27.52 |
| 2026-03-28 00:00 |
17:49:00.50 |
+19:45:52.7 |
HIP 87222 |
26.09 |
| 2026-03-28 12:00 |
17:48:55.26 |
+19:47:24.9 |
HIP 87222 |
24.72 |
| 2026-03-29 00:00 |
17:48:49.92 |
+19:48:56.9 |
HIP 87222 |
23.45 |
| 2026-03-29 12:00 |
17:48:44.49 |
+19:50:28.9 |
HIP 87222 |
22.29 |
| 2026-03-30 00:00 |
17:48:38.96 |
+19:52:00.7 |
HIP 87222 |
21.26 |
| 2026-03-30 12:00 |
17:48:33.33 |
+19:53:32.5 |
HIP 87222 |
20.40 |
| 2026-03-31 00:00 |
17:48:27.60 |
+19:55:04.1 |
HIP 87222 |
19.71 |
| 2026-03-31 12:00 |
17:48:21.78 |
+19:56:35.6 |
HIP 87084 |
18.41 |
| 2026-04-01 00:00 |
17:48:15.87 |
+19:58:07.0 |
HIP 87084 |
16.38 |
| 2026-04-01 12:00 |
17:48:09.85 |
+19:59:38.2 |
HIP 87084 |
14.36 |
| 2026-04-02 00:00 |
17:48:03.75 |
+20:01:09.3 |
HIP 87084 |
12.35 |
| 2026-04-02 12:00 |
17:47:57.54 |
+20:02:40.2 |
HIP 87084 |
10.35 |
| 2026-04-03 00:00 |
17:47:51.24 |
+20:04:11.0 |
HIP 87084 |
8.41 |
| 2026-04-03 12:00 |
17:47:44.85 |
+20:05:41.6 |
HIP 87084 |
6.57 |
| 2026-04-04 00:00 |
17:47:38.36 |
+20:07:12.0 |
HIP 87084 |
4.98 |
| 2026-04-04 12:00 |
17:47:31.77 |
+20:08:42.2 |
HIP 87084 |
3.96 |
| 2026-04-05 00:00 |
17:47:25.09 |
+20:10:12.2 |
HIP 87084 |
4.00 |
| 2026-04-05 12:00 |
17:47:18.31 |
+20:11:42.0 |
HIP 87084 |
5.10 |
| 2026-04-06 00:00 |
17:47:11.44 |
+20:13:11.6 |
HIP 87084 |
6.77 |
| 2026-04-06 12:00 |
17:47:04.48 |
+20:14:41.0 |
HIP 87084 |
8.69 |
| 2026-04-07 00:00 |
17:46:57.42 |
+20:16:10.1 |
HIP 87084 |
10.75 |
| 2026-04-07 12:00 |
17:46:50.26 |
+20:17:39.0 |
HIP 87084 |
12.88 |
| 2026-04-08 00:00 |
17:46:43.01 |
+20:19:07.7 |
HIP 87084 |
15.06 |
| 2026-04-08 12:00 |
17:46:35.67 |
+20:20:36.1 |
HIP 87084 |
17.27 |
| 2026-04-09 00:00 |
17:46:28.23 |
+20:22:04.2 |
HIP 87084 |
19.52 |
| 2026-04-09 12:00 |
17:46:20.70 |
+20:23:32.1 |
HIP 87084 |
21.78 |
| 2026-04-10 00:00 |
17:46:13.07 |
+20:24:59.7 |
HIP 87084 |
24.07 |
| 2026-04-10 12:00 |
17:46:05.36 |
+20:26:26.9 |
HIP 87084 |
26.38 |
| 2026-04-11 00:00 |
17:45:57.54 |
+20:27:53.9 |
HIP 87084 |
28.70 |
| 2026-04-11 12:00 |
17:45:49.64 |
+20:29:20.6 |
HIP 87084 |
31.04 |
| 2026-04-12 00:00 |
17:45:41.64 |
+20:30:46.9 |
HIP 87084 |
33.40 |
| 2026-04-12 12:00 |
17:45:33.55 |
+20:32:12.9 |
HIP 87084 |
35.77 |
| 2026-04-13 00:00 |
17:45:25.37 |
+20:33:38.6 |
HIP 87084 |
38.16 |
| 2026-04-13 12:00 |
17:45:17.10 |
+20:35:04.0 |
HIP 86666 |
39.87 |
| 2026-04-14 00:00 |
17:45:08.73 |
+20:36:28.9 |
HIP 86666 |
37.78 |
| 2026-04-14 12:00 |
17:45:00.28 |
+20:37:53.5 |
HIP 86666 |
35.72 |
| 2026-04-15 00:00 |
17:44:51.73 |
+20:39:17.8 |
HIP 86666 |
33.69 |
| 2026-04-15 12:00 |
17:44:43.09 |
+20:40:41.6 |
HIP 86666 |
31.69 |
| 2026-04-16 00:00 |
17:44:34.36 |
+20:42:05.1 |
HIP 86666 |
29.74 |