メタデータ
| 項目 |
値 |
| Designation |
C/2015 G2 (MASTER) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-05-23T18:53:55.887360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:09Z |
| Obs used |
562 |
| NEO |
- |
| M1 |
12.000 |
| K1 |
6.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2015-08-16.0000000 |
| e |
1.00039511 |
| q (au) |
0.779858 |
| a (au) |
-1973.798171 |
| i (deg) |
147.562721 |
| Ω (om, deg) |
110.058840 |
| ω (w, deg) |
257.458784 |
| M (ma, deg) |
0.000947 |
等級
散乱 + 全体線形
$$
M_a = (11.448 + 3.319\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
11.448 |
| n |
3.319 |
| gf |
1.000 |
| gb |
-0.627 |
| k |
0.956 |
| 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 |
| 2015-03-30 |
2015-04-10 |
-18.6325 |
+0.055 |
| 2015-04-10 |
2015-04-24 |
-23.7298 |
-0.653 |
| 2015-04-24 |
2015-05-23 |
+8.8733 |
-1.009 |
| 2015-05-23 |
2016-02-07 |
+2.0675 |
-1.196 |
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) |
| 2026-05-12 00:00 |
03:04:02.32 |
+44:30:40.6 |
HIP 14385 |
17.63 |
| 2026-05-12 12:00 |
03:04:07.69 |
+44:30:57.3 |
HIP 14385 |
16.84 |
| 2026-05-13 00:00 |
03:04:13.06 |
+44:31:14.3 |
HIP 14385 |
16.07 |
| 2026-05-13 12:00 |
03:04:18.43 |
+44:31:31.4 |
HIP 14385 |
15.33 |
| 2026-05-14 00:00 |
03:04:23.79 |
+44:31:48.8 |
HIP 14385 |
14.62 |
| 2026-05-14 12:00 |
03:04:29.15 |
+44:32:06.4 |
HIP 14385 |
13.96 |
| 2026-05-15 00:00 |
03:04:34.50 |
+44:32:24.2 |
HIP 14385 |
13.33 |
| 2026-05-15 12:00 |
03:04:39.85 |
+44:32:42.3 |
HIP 14385 |
12.76 |
| 2026-05-16 00:00 |
03:04:45.19 |
+44:33:00.5 |
HIP 14385 |
12.25 |
| 2026-05-16 12:00 |
03:04:50.53 |
+44:33:19.0 |
HIP 14385 |
11.80 |
| 2026-05-17 00:00 |
03:04:55.86 |
+44:33:37.6 |
HIP 14385 |
11.43 |
| 2026-05-17 12:00 |
03:05:01.19 |
+44:33:56.5 |
HIP 14385 |
11.13 |
| 2026-05-18 00:00 |
03:05:06.51 |
+44:34:15.6 |
HIP 14385 |
10.93 |
| 2026-05-18 12:00 |
03:05:11.83 |
+44:34:34.9 |
HIP 14385 |
10.82 |
| 2026-05-19 00:00 |
03:05:17.14 |
+44:34:54.4 |
HIP 14385 |
10.80 |
| 2026-05-19 12:00 |
03:05:22.44 |
+44:35:14.1 |
HIP 14385 |
10.88 |
| 2026-05-20 00:00 |
03:05:27.73 |
+44:35:33.9 |
HIP 14385 |
11.05 |
| 2026-05-20 12:00 |
03:05:33.01 |
+44:35:54.0 |
HIP 14385 |
11.32 |
| 2026-05-21 00:00 |
03:05:38.29 |
+44:36:14.3 |
HIP 14385 |
11.66 |
| 2026-05-21 12:00 |
03:05:43.55 |
+44:36:34.8 |
HIP 14385 |
12.08 |
| 2026-05-22 00:00 |
03:05:48.81 |
+44:36:55.5 |
HIP 14385 |
12.58 |
| 2026-05-22 12:00 |
03:05:54.06 |
+44:37:16.4 |
HIP 14385 |
13.13 |
| 2026-05-23 00:00 |
03:05:59.29 |
+44:37:37.4 |
HIP 14385 |
13.73 |
| 2026-05-23 12:00 |
03:06:04.52 |
+44:37:58.7 |
HIP 14385 |
14.38 |
| 2026-05-24 00:00 |
03:06:09.74 |
+44:38:20.1 |
HIP 14385 |
15.07 |
| 2026-05-24 12:00 |
03:06:14.94 |
+44:38:41.7 |
HIP 14385 |
15.79 |
| 2026-05-25 00:00 |
03:06:20.14 |
+44:39:03.6 |
HIP 14385 |
16.55 |
| 2026-05-25 12:00 |
03:06:25.32 |
+44:39:25.6 |
HIP 14385 |
17.33 |
| 2026-05-26 00:00 |
03:06:30.49 |
+44:39:47.7 |
HIP 14385 |
18.13 |
| 2026-05-26 12:00 |
03:06:35.65 |
+44:40:10.1 |
HIP 14385 |
18.95 |
| 2026-05-27 00:00 |
03:06:40.79 |
+44:40:32.6 |
HIP 14385 |
19.79 |
| 2026-05-27 12:00 |
03:06:45.93 |
+44:40:55.4 |
HIP 14385 |
20.64 |
| 2026-05-28 00:00 |
03:06:51.05 |
+44:41:18.3 |
HIP 14385 |
21.51 |
| 2026-05-28 12:00 |
03:06:56.15 |
+44:41:41.3 |
HIP 14385 |
22.38 |
| 2026-05-29 00:00 |
03:07:01.24 |
+44:42:04.6 |
HIP 14385 |
23.27 |
| 2026-05-29 12:00 |
03:07:06.32 |
+44:42:28.0 |
HIP 14385 |
24.16 |
| 2026-05-30 00:00 |
03:07:11.39 |
+44:42:51.6 |
HIP 14385 |
25.06 |
| 2026-05-30 12:00 |
03:07:16.44 |
+44:43:15.4 |
HIP 14668 |
25.02 |
| 2026-05-31 00:00 |
03:07:21.47 |
+44:43:39.3 |
HIP 14668 |
24.04 |
| 2026-05-31 12:00 |
03:07:26.49 |
+44:44:03.4 |
HIP 14668 |
23.07 |
| 2026-06-01 00:00 |
03:07:31.49 |
+44:44:27.7 |
HIP 14668 |
22.10 |
| 2026-06-01 12:00 |
03:07:36.48 |
+44:44:52.1 |
HIP 14668 |
21.13 |
| 2026-06-02 00:00 |
03:07:41.45 |
+44:45:16.7 |
HIP 14668 |
20.16 |