メタデータ
| 項目 |
値 |
| Designation |
C/2012 A2 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2012-11-05T02:25:12.688320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:59Z |
| Obs used |
2643 |
| NEO |
- |
| M1 |
10.600 |
| K1 |
5.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2012-12-02.0000000 |
| e |
0.99638777 |
| q (au) |
3.537475 |
| a (au) |
979.305586 |
| i (deg) |
125.868477 |
| Ω (om, deg) |
191.404772 |
| ω (w, deg) |
101.672043 |
| M (ma, deg) |
0.000865 |
等級
散乱 + 全体線形
$$
M_a = (8.126 + 3.455\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.126 |
| n |
3.455 |
| gf |
1.000 |
| gb |
-0.897 |
| k |
0.999 |
| 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 |
| 2011-04-02 |
2012-11-04 |
+17.9825 |
-10.877 |
| 2012-11-06 |
2013-09-27 |
-3.7538 |
+1.934 |
| 2013-09-27 |
2014-04-15 |
-2.2574 |
+1.298 |
| 2014-04-15 |
2014-10-23 |
+11.5349 |
-9.101 |
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) |
| 2026-06-01 00:00 |
23:36:57.39 |
-53:21:20.3 |
HIP 116729 |
21.73 |
| 2026-06-01 12:00 |
23:36:58.62 |
-53:22:08.4 |
HIP 116729 |
21.49 |
| 2026-06-02 00:00 |
23:36:59.80 |
-53:22:56.7 |
HIP 116729 |
21.29 |
| 2026-06-02 12:00 |
23:37:00.93 |
-53:23:45.3 |
HIP 116729 |
21.12 |
| 2026-06-03 00:00 |
23:37:02.01 |
-53:24:34.0 |
HIP 116729 |
20.99 |
| 2026-06-03 12:00 |
23:37:03.04 |
-53:25:23.0 |
HIP 116729 |
20.90 |
| 2026-06-04 00:00 |
23:37:04.01 |
-53:26:12.2 |
HIP 116729 |
20.86 |
| 2026-06-04 12:00 |
23:37:04.94 |
-53:27:01.6 |
HIP 116729 |
20.85 |
| 2026-06-05 00:00 |
23:37:05.81 |
-53:27:51.2 |
HIP 116729 |
20.89 |
| 2026-06-05 12:00 |
23:37:06.64 |
-53:28:41.1 |
HIP 116729 |
20.96 |
| 2026-06-06 00:00 |
23:37:07.41 |
-53:29:31.1 |
HIP 116729 |
21.08 |
| 2026-06-06 12:00 |
23:37:08.12 |
-53:30:21.3 |
HIP 116738 |
21.07 |
| 2026-06-07 00:00 |
23:37:08.79 |
-53:31:11.8 |
HIP 116738 |
20.94 |
| 2026-06-07 12:00 |
23:37:09.41 |
-53:32:02.4 |
HIP 116738 |
20.85 |
| 2026-06-08 00:00 |
23:37:09.97 |
-53:32:53.2 |
HIP 116738 |
20.80 |
| 2026-06-08 12:00 |
23:37:10.48 |
-53:33:44.3 |
HIP 116738 |
20.79 |
| 2026-06-09 00:00 |
23:37:10.93 |
-53:34:35.5 |
HIP 116738 |
20.83 |
| 2026-06-09 12:00 |
23:37:11.34 |
-53:35:26.9 |
HIP 116738 |
20.91 |
| 2026-06-10 00:00 |
23:37:11.69 |
-53:36:18.4 |
HIP 116738 |
21.04 |
| 2026-06-10 12:00 |
23:37:11.98 |
-53:37:10.2 |
HIP 116738 |
21.21 |
| 2026-06-11 00:00 |
23:37:12.23 |
-53:38:02.1 |
HIP 116738 |
21.42 |
| 2026-06-11 12:00 |
23:37:12.42 |
-53:38:54.2 |
HIP 116738 |
21.67 |
| 2026-06-12 00:00 |
23:37:12.56 |
-53:39:46.5 |
HIP 116738 |
21.96 |
| 2026-06-12 12:00 |
23:37:12.64 |
-53:40:39.0 |
HIP 116738 |
22.29 |
| 2026-06-13 00:00 |
23:37:12.67 |
-53:41:31.6 |
HIP 116738 |
22.65 |
| 2026-06-13 12:00 |
23:37:12.65 |
-53:42:24.3 |
HIP 116738 |
23.06 |
| 2026-06-14 00:00 |
23:37:12.57 |
-53:43:17.2 |
HIP 116738 |
23.49 |
| 2026-06-14 12:00 |
23:37:12.43 |
-53:44:10.3 |
HIP 116738 |
23.96 |
| 2026-06-15 00:00 |
23:37:12.25 |
-53:45:03.5 |
HIP 116738 |
24.46 |
| 2026-06-15 12:00 |
23:37:12.01 |
-53:45:56.9 |
HIP 116738 |
24.99 |
| 2026-06-16 00:00 |
23:37:11.71 |
-53:46:50.4 |
HIP 116586 |
24.64 |
| 2026-06-16 12:00 |
23:37:11.36 |
-53:47:44.0 |
HIP 116586 |
23.77 |
| 2026-06-17 00:00 |
23:37:10.96 |
-53:48:37.7 |
HIP 116586 |
22.89 |
| 2026-06-17 12:00 |
23:37:10.50 |
-53:49:31.6 |
HIP 116586 |
22.02 |
| 2026-06-18 00:00 |
23:37:09.99 |
-53:50:25.6 |
HIP 116586 |
21.14 |
| 2026-06-18 12:00 |
23:37:09.42 |
-53:51:19.8 |
HIP 116586 |
20.27 |
| 2026-06-19 00:00 |
23:37:08.80 |
-53:52:14.0 |
HIP 116586 |
19.40 |
| 2026-06-19 12:00 |
23:37:08.12 |
-53:53:08.4 |
HIP 116586 |
18.54 |
| 2026-06-20 00:00 |
23:37:07.39 |
-53:54:02.9 |
HIP 116586 |
17.68 |
| 2026-06-20 12:00 |
23:37:06.60 |
-53:54:57.4 |
HIP 116586 |
16.82 |
| 2026-06-21 00:00 |
23:37:05.76 |
-53:55:52.1 |
HIP 116586 |
15.97 |
| 2026-06-21 12:00 |
23:37:04.86 |
-53:56:46.9 |
HIP 116586 |
15.14 |
| 2026-06-22 00:00 |
23:37:03.91 |
-53:57:41.7 |
HIP 116586 |
14.31 |