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) |
| 2026-07-29 00:00 |
22:25:54.80 |
+11:20:08.4 |
HIP 110676 |
14.40 |
| 2026-07-29 12:00 |
22:25:45.67 |
+11:20:23.7 |
HIP 110676 |
12.95 |
| 2026-07-30 00:00 |
22:25:36.49 |
+11:20:38.3 |
HIP 110676 |
11.76 |
| 2026-07-30 12:00 |
22:25:27.26 |
+11:20:52.1 |
HIP 110676 |
10.93 |
| 2026-07-31 00:00 |
22:25:17.99 |
+11:21:05.2 |
HIP 110676 |
10.54 |
| 2026-07-31 12:00 |
22:25:08.66 |
+11:21:17.6 |
HIP 110676 |
10.65 |
| 2026-08-01 00:00 |
22:24:59.30 |
+11:21:29.2 |
HIP 110676 |
11.26 |
| 2026-08-01 12:00 |
22:24:49.88 |
+11:21:40.1 |
HIP 110676 |
12.29 |
| 2026-08-02 00:00 |
22:24:40.43 |
+11:21:50.3 |
HIP 110676 |
13.66 |
| 2026-08-02 12:00 |
22:24:30.93 |
+11:21:59.7 |
HIP 110676 |
15.27 |
| 2026-08-03 00:00 |
22:24:21.39 |
+11:22:08.4 |
HIP 110676 |
17.07 |
| 2026-08-03 12:00 |
22:24:11.81 |
+11:22:16.4 |
HIP 110676 |
19.00 |
| 2026-08-04 00:00 |
22:24:02.18 |
+11:22:23.6 |
HIP 110676 |
21.03 |
| 2026-08-04 12:00 |
22:23:52.52 |
+11:22:30.1 |
HIP 110676 |
23.14 |
| 2026-08-05 00:00 |
22:23:42.82 |
+11:22:35.9 |
HIP 110676 |
25.31 |
| 2026-08-05 12:00 |
22:23:33.08 |
+11:22:41.0 |
HIP 110447 |
25.69 |
| 2026-08-06 00:00 |
22:23:23.31 |
+11:22:45.3 |
HIP 110447 |
24.08 |
| 2026-08-06 12:00 |
22:23:13.50 |
+11:22:49.0 |
HIP 110447 |
22.60 |
| 2026-08-07 00:00 |
22:23:03.65 |
+11:22:51.9 |
HIP 110447 |
21.27 |
| 2026-08-07 12:00 |
22:22:53.77 |
+11:22:54.0 |
HIP 110447 |
20.12 |
| 2026-08-08 00:00 |
22:22:43.86 |
+11:22:55.5 |
HIP 110447 |
19.20 |
| 2026-08-08 12:00 |
22:22:33.92 |
+11:22:56.2 |
HIP 110447 |
18.55 |
| 2026-08-09 00:00 |
22:22:23.94 |
+11:22:56.3 |
HIP 110390 |
17.40 |
| 2026-08-09 12:00 |
22:22:13.94 |
+11:22:55.6 |
HIP 110390 |
15.78 |
| 2026-08-10 00:00 |
22:22:03.90 |
+11:22:54.2 |
HIP 110390 |
14.40 |
| 2026-08-10 12:00 |
22:21:53.84 |
+11:22:52.1 |
HIP 110390 |
13.35 |
| 2026-08-11 00:00 |
22:21:43.75 |
+11:22:49.2 |
HIP 110390 |
12.70 |
| 2026-08-11 12:00 |
22:21:33.63 |
+11:22:45.7 |
HIP 110390 |
12.53 |
| 2026-08-12 00:00 |
22:21:23.49 |
+11:22:41.5 |
HIP 110390 |
12.86 |
| 2026-08-12 12:00 |
22:21:13.33 |
+11:22:36.6 |
HIP 110390 |
13.65 |
| 2026-08-13 00:00 |
22:21:03.14 |
+11:22:31.0 |
HIP 110390 |
14.84 |
| 2026-08-13 12:00 |
22:20:52.93 |
+11:22:24.7 |
HIP 110390 |
16.34 |
| 2026-08-14 00:00 |
22:20:42.70 |
+11:22:17.7 |
HIP 110390 |
18.07 |
| 2026-08-14 12:00 |
22:20:32.45 |
+11:22:10.0 |
HIP 110390 |
19.98 |
| 2026-08-15 00:00 |
22:20:22.18 |
+11:22:01.7 |
HIP 110286 |
19.68 |
| 2026-08-15 12:00 |
22:20:11.90 |
+11:21:52.6 |
HIP 110286 |
19.67 |
| 2026-08-16 00:00 |
22:20:01.59 |
+11:21:42.9 |
HIP 110286 |
19.96 |
| 2026-08-16 12:00 |
22:19:51.28 |
+11:21:32.5 |
HIP 110286 |
20.55 |
| 2026-08-17 00:00 |
22:19:40.95 |
+11:21:21.5 |
HIP 110286 |
21.42 |
| 2026-08-17 12:00 |
22:19:30.60 |
+11:21:09.8 |
HIP 110286 |
22.54 |
| 2026-08-18 00:00 |
22:19:20.25 |
+11:20:57.5 |
HIP 110286 |
23.87 |
| 2026-08-18 12:00 |
22:19:09.88 |
+11:20:44.5 |
HIP 110286 |
25.38 |
| 2026-08-19 00:00 |
22:18:59.51 |
+11:20:30.8 |
HIP 110286 |
27.05 |