C/2012 A2 (LINEAR)
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) |
| 2026-02-03 00:00 |
23:18:28.00 |
-52:54:15.3 |
HIP 115020 |
7.75 |
| 2026-02-03 12:00 |
23:18:32.95 |
-52:53:40.9 |
HIP 115020 |
8.14 |
| 2026-02-04 00:00 |
23:18:37.92 |
-52:53:06.8 |
HIP 115020 |
8.63 |
| 2026-02-04 12:00 |
23:18:42.92 |
-52:52:32.9 |
HIP 115020 |
9.19 |
| 2026-02-05 00:00 |
23:18:47.94 |
-52:51:59.2 |
HIP 115020 |
9.81 |
| 2026-02-05 12:00 |
23:18:53.00 |
-52:51:25.8 |
HIP 115020 |
10.49 |
| 2026-02-06 00:00 |
23:18:58.08 |
-52:50:52.7 |
HIP 115020 |
11.21 |
| 2026-02-06 12:00 |
23:19:03.18 |
-52:50:19.8 |
HIP 115020 |
11.97 |
| 2026-02-07 00:00 |
23:19:08.31 |
-52:49:47.1 |
HIP 115020 |
12.75 |
| 2026-02-07 12:00 |
23:19:13.47 |
-52:49:14.8 |
HIP 115020 |
13.56 |
| 2026-02-08 00:00 |
23:19:18.65 |
-52:48:42.7 |
HIP 115020 |
14.39 |
| 2026-02-08 12:00 |
23:19:23.86 |
-52:48:10.9 |
HIP 115020 |
15.24 |
| 2026-02-09 00:00 |
23:19:29.09 |
-52:47:39.3 |
HIP 115020 |
16.10 |
| 2026-02-09 12:00 |
23:19:34.34 |
-52:47:08.1 |
HIP 115020 |
16.97 |
| 2026-02-10 00:00 |
23:19:39.62 |
-52:46:37.1 |
HIP 115020 |
17.86 |
| 2026-02-10 12:00 |
23:19:44.92 |
-52:46:06.4 |
HIP 115020 |
18.75 |
| 2026-02-11 00:00 |
23:19:50.24 |
-52:45:35.9 |
HIP 115020 |
19.65 |
| 2026-02-11 12:00 |
23:19:55.59 |
-52:45:05.8 |
HIP 115020 |
20.56 |
| 2026-02-12 00:00 |
23:20:00.95 |
-52:44:35.9 |
HIP 115020 |
21.47 |
| 2026-02-12 12:00 |
23:20:06.34 |
-52:44:06.4 |
HIP 115020 |
22.39 |
| 2026-02-13 00:00 |
23:20:11.75 |
-52:43:37.1 |
HIP 115330 |
22.77 |
| 2026-02-13 12:00 |
23:20:17.18 |
-52:43:08.1 |
HIP 115330 |
21.92 |
| 2026-02-14 00:00 |
23:20:22.63 |
-52:42:39.4 |
HIP 115330 |
21.08 |
| 2026-02-14 12:00 |
23:20:28.10 |
-52:42:11.0 |
HIP 115330 |
20.25 |
| 2026-02-15 00:00 |
23:20:33.59 |
-52:41:42.9 |
HIP 115330 |
19.43 |
| 2026-02-15 12:00 |
23:20:39.10 |
-52:41:15.2 |
HIP 115330 |
18.63 |
| 2026-02-16 00:00 |
23:20:44.63 |
-52:40:47.7 |
HIP 115330 |
17.85 |
| 2026-02-16 12:00 |
23:20:50.18 |
-52:40:20.5 |
HIP 115330 |
17.09 |
| 2026-02-17 00:00 |
23:20:55.74 |
-52:39:53.6 |
HIP 115330 |
16.35 |
| 2026-02-17 12:00 |
23:21:01.32 |
-52:39:27.1 |
HIP 115330 |
15.65 |
| 2026-02-18 00:00 |
23:21:06.92 |
-52:39:00.9 |
HIP 115330 |
14.97 |
| 2026-02-18 12:00 |
23:21:12.53 |
-52:38:35.0 |
HIP 115330 |
14.33 |
| 2026-02-19 00:00 |
23:21:18.17 |
-52:38:09.4 |
HIP 115330 |
13.73 |
| 2026-02-19 12:00 |
23:21:23.81 |
-52:37:44.1 |
HIP 115330 |
13.18 |
| 2026-02-20 00:00 |
23:21:29.47 |
-52:37:19.1 |
HIP 115330 |
12.69 |
| 2026-02-20 12:00 |
23:21:35.15 |
-52:36:54.5 |
HIP 115330 |
12.25 |
| 2026-02-21 00:00 |
23:21:40.84 |
-52:36:30.2 |
HIP 115330 |
11.88 |
| 2026-02-21 12:00 |
23:21:46.55 |
-52:36:06.3 |
HIP 115330 |
11.59 |
| 2026-02-22 00:00 |
23:21:52.26 |
-52:35:42.6 |
HIP 115330 |
11.37 |
| 2026-02-22 12:00 |
23:21:57.99 |
-52:35:19.3 |
HIP 115330 |
11.24 |
| 2026-02-23 00:00 |
23:22:03.74 |
-52:34:56.4 |
HIP 115330 |
11.19 |
| 2026-02-23 12:00 |
23:22:09.49 |
-52:34:33.7 |
HIP 115330 |
11.23 |
| 2026-02-24 00:00 |
23:22:15.26 |
-52:34:11.4 |
HIP 115330 |
11.35 |