メタデータ
| 項目 |
値 |
| Designation |
C/2021 C5 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-02-11T00:59:44.805120Z |
| Orbit solution date (soln_date, UTC) |
2024-07-08T10:14:37Z |
| Obs used |
456 |
| NEO |
- |
| M1 |
12.100 |
| K1 |
5.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-02-12T08:17:13.660800Z |
| Discovery magnitude (MPC) |
21.01 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2022-03-02.0000000 |
| e |
0.99926635 |
| q (au) |
3.241820 |
| a (au) |
4418.763332 |
| i (deg) |
50.784623 |
| Ω (om, deg) |
323.689906 |
| ω (w, deg) |
270.917360 |
| M (ma, deg) |
359.998839 |
等級
散乱 + 全体線形
$$
M_a = (12.668 + 3.655\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.668 |
| n |
3.655 |
| gf |
1.000 |
| gb |
-0.758 |
| k |
0.800 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2020-12-22 |
2022-01-05 |
+4.2672 |
-3.352 |
| 2022-01-05 |
2022-06-07 |
+5.6932 |
-3.927 |
| 2022-06-07 |
2023-02-07 |
-20.1432 |
+11.501 |
| 2023-02-16 |
2024-07-03 |
+12.5302 |
-5.302 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
22:34:04.15 |
+08:27:17.5 |
HIP 111572 |
32.98 |
| 2026-05-12 12:00 |
22:34:07.76 |
+08:29:01.9 |
HIP 111572 |
32.77 |
| 2026-05-13 00:00 |
22:34:11.28 |
+08:30:46.0 |
HIP 111572 |
32.70 |
| 2026-05-13 12:00 |
22:34:14.72 |
+08:32:29.9 |
HIP 111572 |
32.75 |
| 2026-05-14 00:00 |
22:34:18.07 |
+08:34:13.5 |
HIP 111572 |
32.94 |
| 2026-05-14 12:00 |
22:34:21.35 |
+08:35:56.7 |
HIP 111572 |
33.24 |
| 2026-05-15 00:00 |
22:34:24.53 |
+08:37:39.6 |
HIP 111572 |
33.67 |
| 2026-05-15 12:00 |
22:34:27.63 |
+08:39:22.3 |
HIP 111383 |
33.52 |
| 2026-05-16 00:00 |
22:34:30.65 |
+08:41:04.6 |
HIP 111383 |
32.04 |
| 2026-05-16 12:00 |
22:34:33.58 |
+08:42:46.6 |
HIP 111383 |
30.61 |
| 2026-05-17 00:00 |
22:34:36.42 |
+08:44:28.3 |
HIP 111383 |
29.22 |
| 2026-05-17 12:00 |
22:34:39.18 |
+08:46:09.6 |
HIP 111383 |
27.88 |
| 2026-05-18 00:00 |
22:34:41.85 |
+08:47:50.6 |
HIP 111383 |
26.59 |
| 2026-05-18 12:00 |
22:34:44.43 |
+08:49:31.3 |
HIP 111383 |
25.36 |
| 2026-05-19 00:00 |
22:34:46.93 |
+08:51:11.6 |
HIP 111383 |
24.19 |
| 2026-05-19 12:00 |
22:34:49.34 |
+08:52:51.5 |
HIP 111383 |
23.10 |
| 2026-05-20 00:00 |
22:34:51.66 |
+08:54:31.2 |
HIP 111383 |
22.09 |
| 2026-05-20 12:00 |
22:34:53.89 |
+08:56:10.4 |
HIP 111383 |
21.16 |
| 2026-05-21 00:00 |
22:34:56.04 |
+08:57:49.3 |
HIP 111383 |
20.33 |
| 2026-05-21 12:00 |
22:34:58.10 |
+08:59:27.8 |
HIP 111383 |
19.60 |
| 2026-05-22 00:00 |
22:35:00.07 |
+09:01:06.0 |
HIP 111383 |
18.99 |
| 2026-05-22 12:00 |
22:35:01.95 |
+09:02:43.8 |
HIP 111383 |
18.50 |
| 2026-05-23 00:00 |
22:35:03.75 |
+09:04:21.2 |
HIP 111383 |
18.14 |
| 2026-05-23 12:00 |
22:35:05.46 |
+09:05:58.2 |
HIP 111383 |
17.91 |
| 2026-05-24 00:00 |
22:35:07.07 |
+09:07:34.9 |
HIP 111383 |
17.82 |
| 2026-05-24 12:00 |
22:35:08.60 |
+09:09:11.2 |
HIP 111383 |
17.86 |
| 2026-05-25 00:00 |
22:35:10.04 |
+09:10:47.0 |
HIP 111383 |
18.03 |
| 2026-05-25 12:00 |
22:35:11.39 |
+09:12:22.5 |
HIP 111383 |
18.32 |
| 2026-05-26 00:00 |
22:35:12.66 |
+09:13:57.6 |
HIP 111383 |
18.73 |
| 2026-05-26 12:00 |
22:35:13.83 |
+09:15:32.3 |
HIP 111383 |
19.24 |
| 2026-05-27 00:00 |
22:35:14.91 |
+09:17:06.5 |
HIP 111399 |
18.80 |
| 2026-05-27 12:00 |
22:35:15.91 |
+09:18:40.4 |
HIP 111399 |
18.37 |
| 2026-05-28 00:00 |
22:35:16.81 |
+09:20:13.9 |
HIP 111399 |
18.05 |
| 2026-05-28 12:00 |
22:35:17.63 |
+09:21:46.9 |
HIP 111399 |
17.83 |
| 2026-05-29 00:00 |
22:35:18.35 |
+09:23:19.5 |
HIP 111399 |
17.74 |
| 2026-05-29 12:00 |
22:35:18.99 |
+09:24:51.7 |
HIP 111399 |
17.75 |
| 2026-05-30 00:00 |
22:35:19.53 |
+09:26:23.5 |
HIP 111399 |
17.88 |
| 2026-05-30 12:00 |
22:35:19.99 |
+09:27:54.8 |
HIP 111399 |
18.12 |
| 2026-05-31 00:00 |
22:35:20.35 |
+09:29:25.7 |
HIP 111399 |
18.45 |
| 2026-05-31 12:00 |
22:35:20.63 |
+09:30:56.1 |
HIP 111399 |
18.88 |
| 2026-06-01 00:00 |
22:35:20.81 |
+09:32:26.1 |
HIP 111399 |
19.39 |
| 2026-06-01 12:00 |
22:35:20.91 |
+09:33:55.7 |
HIP 111399 |
19.98 |
| 2026-06-02 00:00 |
22:35:20.91 |
+09:35:24.8 |
HIP 111399 |
20.64 |