C/2021 R2 (PANSTARRS)
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) |
| 2026-02-03 00:00 |
17:49:40.41 |
+17:21:31.6 |
HIP 87267 |
35.76 |
| 2026-02-03 12:00 |
17:49:44.20 |
+17:22:30.8 |
HIP 87267 |
34.70 |
| 2026-02-04 00:00 |
17:49:47.91 |
+17:23:30.5 |
HIP 87267 |
33.64 |
| 2026-02-04 12:00 |
17:49:51.57 |
+17:24:30.9 |
HIP 87267 |
32.60 |
| 2026-02-05 00:00 |
17:49:55.16 |
+17:25:31.9 |
HIP 87267 |
31.57 |
| 2026-02-05 12:00 |
17:49:58.69 |
+17:26:33.5 |
HIP 87267 |
30.56 |
| 2026-02-06 00:00 |
17:50:02.15 |
+17:27:35.8 |
HIP 87267 |
29.56 |
| 2026-02-06 12:00 |
17:50:05.54 |
+17:28:38.6 |
HIP 87267 |
28.57 |
| 2026-02-07 00:00 |
17:50:08.87 |
+17:29:41.9 |
HIP 87267 |
27.60 |
| 2026-02-07 12:00 |
17:50:12.14 |
+17:30:45.9 |
HIP 87267 |
26.64 |
| 2026-02-08 00:00 |
17:50:15.33 |
+17:31:50.5 |
HIP 87267 |
25.71 |
| 2026-02-08 12:00 |
17:50:18.46 |
+17:32:55.6 |
HIP 87267 |
24.80 |
| 2026-02-09 00:00 |
17:50:21.52 |
+17:34:01.4 |
HIP 87267 |
23.91 |
| 2026-02-09 12:00 |
17:50:24.51 |
+17:35:07.7 |
HIP 87267 |
23.05 |
| 2026-02-10 00:00 |
17:50:27.43 |
+17:36:14.5 |
HIP 87267 |
22.22 |
| 2026-02-10 12:00 |
17:50:30.28 |
+17:37:21.9 |
HIP 87267 |
21.42 |
| 2026-02-11 00:00 |
17:50:33.06 |
+17:38:29.9 |
HIP 87267 |
20.66 |
| 2026-02-11 12:00 |
17:50:35.77 |
+17:39:38.5 |
HIP 87267 |
19.94 |
| 2026-02-12 00:00 |
17:50:38.41 |
+17:40:47.5 |
HIP 87267 |
19.27 |
| 2026-02-12 12:00 |
17:50:40.97 |
+17:41:57.2 |
HIP 87267 |
18.65 |
| 2026-02-13 00:00 |
17:50:43.46 |
+17:43:07.3 |
HIP 87267 |
18.08 |
| 2026-02-13 12:00 |
17:50:45.88 |
+17:44:18.0 |
HIP 87267 |
17.57 |
| 2026-02-14 00:00 |
17:50:48.22 |
+17:45:29.2 |
HIP 87267 |
17.13 |
| 2026-02-14 12:00 |
17:50:50.49 |
+17:46:41.0 |
HIP 87267 |
16.76 |
| 2026-02-15 00:00 |
17:50:52.69 |
+17:47:53.2 |
HIP 87267 |
16.47 |
| 2026-02-15 12:00 |
17:50:54.81 |
+17:49:06.0 |
HIP 87267 |
16.26 |
| 2026-02-16 00:00 |
17:50:56.85 |
+17:50:19.3 |
HIP 87267 |
16.13 |
| 2026-02-16 12:00 |
17:50:58.82 |
+17:51:33.1 |
HIP 87267 |
16.09 |
| 2026-02-17 00:00 |
17:51:00.71 |
+17:52:47.3 |
HIP 87267 |
16.14 |
| 2026-02-17 12:00 |
17:51:02.52 |
+17:54:02.1 |
HIP 87267 |
16.28 |
| 2026-02-18 00:00 |
17:51:04.25 |
+17:55:17.4 |
HIP 87267 |
16.49 |
| 2026-02-18 12:00 |
17:51:05.91 |
+17:56:33.1 |
HIP 87267 |
16.80 |
| 2026-02-19 00:00 |
17:51:07.48 |
+17:57:49.3 |
HIP 87267 |
17.18 |
| 2026-02-19 12:00 |
17:51:08.98 |
+17:59:05.9 |
HIP 87267 |
17.63 |
| 2026-02-20 00:00 |
17:51:10.39 |
+18:00:23.1 |
HIP 87267 |
18.15 |
| 2026-02-20 12:00 |
17:51:11.73 |
+18:01:40.6 |
HIP 87267 |
18.73 |
| 2026-02-21 00:00 |
17:51:12.98 |
+18:02:58.6 |
HIP 87355 |
18.34 |
| 2026-02-21 12:00 |
17:51:14.16 |
+18:04:17.1 |
HIP 87355 |
17.11 |
| 2026-02-22 00:00 |
17:51:15.25 |
+18:05:36.0 |
HIP 87355 |
15.89 |
| 2026-02-22 12:00 |
17:51:16.26 |
+18:06:55.3 |
HIP 87355 |
14.68 |
| 2026-02-23 00:00 |
17:51:17.19 |
+18:08:15.0 |
HIP 87355 |
13.48 |
| 2026-02-23 12:00 |
17:51:18.03 |
+18:09:35.2 |
HIP 87355 |
12.29 |
| 2026-02-24 00:00 |
17:51:18.79 |
+18:10:55.7 |
HIP 87355 |
11.13 |