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) |
| 2026-09-20 00:00 |
22:08:21.80 |
+10:47:23.0 |
HIP 109226 |
10.63 |
| 2026-09-20 12:00 |
22:08:12.96 |
+10:46:38.9 |
HIP 109226 |
8.36 |
| 2026-09-21 00:00 |
22:08:04.18 |
+10:45:54.5 |
HIP 109226 |
6.12 |
| 2026-09-21 12:00 |
22:07:55.45 |
+10:45:10.0 |
HIP 109226 |
3.94 |
| 2026-09-22 00:00 |
22:07:46.79 |
+10:44:25.1 |
HIP 109226 |
1.98 |
| 2026-09-22 12:00 |
22:07:38.18 |
+10:43:40.1 |
HIP 109226 |
1.58 |
| 2026-09-23 00:00 |
22:07:29.62 |
+10:42:54.8 |
HIP 109226 |
3.33 |
| 2026-09-23 12:00 |
22:07:21.13 |
+10:42:09.3 |
HIP 109226 |
5.44 |
| 2026-09-24 00:00 |
22:07:12.70 |
+10:41:23.7 |
HIP 109226 |
7.59 |
| 2026-09-24 12:00 |
22:07:04.33 |
+10:40:37.8 |
HIP 109226 |
9.76 |
| 2026-09-25 00:00 |
22:06:56.02 |
+10:39:51.8 |
HIP 109226 |
11.93 |
| 2026-09-25 12:00 |
22:06:47.77 |
+10:39:05.5 |
HIP 109226 |
14.09 |
| 2026-09-26 00:00 |
22:06:39.58 |
+10:38:19.1 |
HIP 109226 |
16.24 |
| 2026-09-26 12:00 |
22:06:31.46 |
+10:37:32.6 |
HIP 109226 |
18.37 |
| 2026-09-27 00:00 |
22:06:23.40 |
+10:36:45.9 |
HIP 109226 |
20.50 |
| 2026-09-27 12:00 |
22:06:15.40 |
+10:35:59.0 |
HIP 109226 |
22.61 |
| 2026-09-28 00:00 |
22:06:07.47 |
+10:35:12.0 |
HIP 109226 |
24.71 |
| 2026-09-28 12:00 |
22:05:59.61 |
+10:34:24.8 |
HIP 109226 |
26.79 |
| 2026-09-29 00:00 |
22:05:51.81 |
+10:33:37.6 |
HIP 108963 |
27.62 |
| 2026-09-29 12:00 |
22:05:44.08 |
+10:32:50.2 |
HIP 108963 |
25.71 |
| 2026-09-30 00:00 |
22:05:36.42 |
+10:32:02.7 |
HIP 108963 |
23.84 |
| 2026-09-30 12:00 |
22:05:28.83 |
+10:31:15.0 |
HIP 108963 |
22.02 |
| 2026-10-01 00:00 |
22:05:21.31 |
+10:30:27.3 |
HIP 108963 |
20.24 |
| 2026-10-01 12:00 |
22:05:13.85 |
+10:29:39.5 |
HIP 108963 |
18.51 |
| 2026-10-02 00:00 |
22:05:06.47 |
+10:28:51.6 |
HIP 108963 |
16.86 |
| 2026-10-02 12:00 |
22:04:59.16 |
+10:28:03.6 |
HIP 108963 |
15.28 |
| 2026-10-03 00:00 |
22:04:51.92 |
+10:27:15.6 |
HIP 108963 |
13.82 |
| 2026-10-03 12:00 |
22:04:44.75 |
+10:26:27.5 |
HIP 108963 |
12.50 |
| 2026-10-04 00:00 |
22:04:37.65 |
+10:25:39.3 |
HIP 108963 |
11.35 |
| 2026-10-04 12:00 |
22:04:30.63 |
+10:24:51.1 |
HIP 108963 |
10.43 |
| 2026-10-05 00:00 |
22:04:23.68 |
+10:24:02.8 |
HIP 108963 |
9.80 |
| 2026-10-05 12:00 |
22:04:16.81 |
+10:23:14.5 |
HIP 108963 |
9.50 |
| 2026-10-06 00:00 |
22:04:10.01 |
+10:22:26.2 |
HIP 108963 |
9.55 |
| 2026-10-06 12:00 |
22:04:03.29 |
+10:21:37.9 |
HIP 108963 |
9.94 |
| 2026-10-07 00:00 |
22:03:56.65 |
+10:20:49.5 |
HIP 108963 |
10.62 |
| 2026-10-07 12:00 |
22:03:50.08 |
+10:20:01.2 |
HIP 108963 |
11.54 |
| 2026-10-08 00:00 |
22:03:43.60 |
+10:19:12.8 |
HIP 108963 |
12.63 |
| 2026-10-08 12:00 |
22:03:37.19 |
+10:18:24.5 |
HIP 108963 |
13.85 |
| 2026-10-09 00:00 |
22:03:30.86 |
+10:17:36.2 |
HIP 108963 |
15.16 |
| 2026-10-09 12:00 |
22:03:24.60 |
+10:16:47.9 |
HIP 108963 |
16.53 |
| 2026-10-10 00:00 |
22:03:18.43 |
+10:15:59.6 |
HIP 108963 |
17.95 |
| 2026-10-10 12:00 |
22:03:12.34 |
+10:15:11.4 |
HIP 108963 |
19.39 |
| 2026-10-11 00:00 |
22:03:06.33 |
+10:14:23.3 |
HIP 108963 |
20.86 |