メタデータ
| 項目 |
値 |
| Designation |
C/2014 A4 (SONEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-09-05T20:45:05.630400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:46Z |
| Obs used |
2742 |
| NEO |
- |
| M1 |
9.500 |
| K1 |
5.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2015-10-28.0000000 |
| e |
1.00085476 |
| q (au) |
4.180180 |
| a (au) |
-4890.464363 |
| i (deg) |
121.359968 |
| Ω (om, deg) |
29.727220 |
| ω (w, deg) |
356.788414 |
| M (ma, deg) |
0.000150 |
等級
散乱 + 全体線形
$$
M_a = (10.149 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.149 |
| n |
2.000 |
| gf |
0.830 |
| gb |
-0.500 |
| k |
0.927 |
| δ90 |
1.000 |
| 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 |
| 2014-01-12 |
2014-10-21 |
+6.8415 |
-5.586 |
| 2014-10-21 |
2015-09-01 |
-9.4186 |
+6.023 |
| 2015-09-06 |
2016-12-24 |
-2.1233 |
+1.498 |
| 2016-12-24 |
2017-09-17 |
+16.6300 |
-12.756 |
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 |
16:39:37.82 |
+22:53:35.4 |
HIP 81577 |
6.51 |
| 2026-06-01 12:00 |
16:39:31.84 |
+22:53:38.3 |
HIP 81575 |
6.55 |
| 2026-06-02 00:00 |
16:39:25.86 |
+22:53:40.7 |
HIP 81575 |
6.86 |
| 2026-06-02 12:00 |
16:39:19.89 |
+22:53:42.7 |
HIP 81575 |
7.43 |
| 2026-06-03 00:00 |
16:39:13.91 |
+22:53:44.3 |
HIP 81575 |
8.19 |
| 2026-06-03 12:00 |
16:39:07.94 |
+22:53:45.3 |
HIP 81575 |
9.11 |
| 2026-06-04 00:00 |
16:39:01.97 |
+22:53:45.9 |
HIP 81575 |
10.13 |
| 2026-06-04 12:00 |
16:38:56.01 |
+22:53:46.0 |
HIP 81575 |
11.24 |
| 2026-06-05 00:00 |
16:38:50.04 |
+22:53:45.7 |
HIP 81575 |
12.40 |
| 2026-06-05 12:00 |
16:38:44.08 |
+22:53:44.9 |
HIP 81575 |
13.60 |
| 2026-06-06 00:00 |
16:38:38.13 |
+22:53:43.6 |
HIP 81575 |
14.83 |
| 2026-06-06 12:00 |
16:38:32.18 |
+22:53:41.9 |
HIP 81575 |
16.09 |
| 2026-06-07 00:00 |
16:38:26.23 |
+22:53:39.7 |
HIP 81575 |
17.37 |
| 2026-06-07 12:00 |
16:38:20.29 |
+22:53:37.0 |
HIP 81575 |
18.66 |
| 2026-06-08 00:00 |
16:38:14.36 |
+22:53:33.8 |
HIP 81357 |
18.60 |
| 2026-06-08 12:00 |
16:38:08.43 |
+22:53:30.2 |
HIP 81357 |
17.23 |
| 2026-06-09 00:00 |
16:38:02.51 |
+22:53:26.1 |
HIP 81357 |
15.87 |
| 2026-06-09 12:00 |
16:37:56.60 |
+22:53:21.6 |
HIP 81357 |
14.50 |
| 2026-06-10 00:00 |
16:37:50.69 |
+22:53:16.6 |
HIP 81357 |
13.14 |
| 2026-06-10 12:00 |
16:37:44.79 |
+22:53:11.1 |
HIP 81357 |
11.78 |
| 2026-06-11 00:00 |
16:37:38.90 |
+22:53:05.1 |
HIP 81357 |
10.42 |
| 2026-06-11 12:00 |
16:37:33.02 |
+22:52:58.7 |
HIP 81357 |
9.06 |
| 2026-06-12 00:00 |
16:37:27.15 |
+22:52:51.8 |
HIP 81357 |
7.70 |
| 2026-06-12 12:00 |
16:37:21.28 |
+22:52:44.5 |
HIP 81357 |
6.35 |
| 2026-06-13 00:00 |
16:37:15.43 |
+22:52:36.6 |
HIP 81357 |
4.99 |
| 2026-06-13 12:00 |
16:37:09.59 |
+22:52:28.3 |
HIP 81357 |
3.64 |
| 2026-06-14 00:00 |
16:37:03.76 |
+22:52:19.6 |
HIP 81357 |
2.29 |
| 2026-06-14 12:00 |
16:36:57.94 |
+22:52:10.3 |
HIP 81357 |
0.94 |
| 2026-06-15 00:00 |
16:36:52.14 |
+22:52:00.6 |
HIP 81357 |
0.41 |
| 2026-06-15 12:00 |
16:36:46.34 |
+22:51:50.5 |
HIP 81357 |
1.75 |
| 2026-06-16 00:00 |
16:36:40.56 |
+22:51:39.8 |
HIP 81357 |
3.10 |
| 2026-06-16 12:00 |
16:36:34.80 |
+22:51:28.8 |
HIP 81357 |
4.44 |
| 2026-06-17 00:00 |
16:36:29.04 |
+22:51:17.2 |
HIP 81357 |
5.78 |
| 2026-06-17 12:00 |
16:36:23.30 |
+22:51:05.2 |
HIP 81357 |
7.11 |
| 2026-06-18 00:00 |
16:36:17.58 |
+22:50:52.7 |
HIP 81357 |
8.45 |
| 2026-06-18 12:00 |
16:36:11.87 |
+22:50:39.8 |
HIP 81251 |
8.18 |
| 2026-06-19 00:00 |
16:36:06.18 |
+22:50:26.4 |
HIP 81251 |
7.02 |
| 2026-06-19 12:00 |
16:36:00.50 |
+22:50:12.6 |
HIP 81251 |
5.92 |
| 2026-06-20 00:00 |
16:35:54.84 |
+22:49:58.3 |
HIP 81251 |
4.94 |
| 2026-06-20 12:00 |
16:35:49.19 |
+22:49:43.5 |
HIP 81251 |
4.14 |
| 2026-06-21 00:00 |
16:35:43.57 |
+22:49:28.3 |
HIP 81251 |
3.66 |
| 2026-06-21 12:00 |
16:35:37.96 |
+22:49:12.6 |
HIP 81251 |
3.61 |
| 2026-06-22 00:00 |
16:35:32.37 |
+22:48:56.5 |
HIP 81251 |
4.01 |