C/2015 K2 (PANSTARRS)
メタデータ
| 項目 |
値 |
| Designation |
C/2015 K2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-06-08T19:07:06.248640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:11Z |
| Obs used |
54 |
| NEO |
- |
| M1 |
20.700 |
| K1 |
10.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2015-05-26.0000000 |
| e |
0.99444359 |
| q (au) |
1.455282 |
| a (au) |
261.910605 |
| i (deg) |
29.110346 |
| Ω (om, deg) |
223.713883 |
| ω (w, deg) |
15.770089 |
| M (ma, deg) |
359.996792 |
等級
散乱 + 全体線形
$$
M_a = (20.000 + 3.100\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
20.000 |
| n |
3.100 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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 |
| 2015-06-09 |
2021-08-02 |
-22.5005 |
+3.860 |
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 |
01:50:44.70 |
+17:07:35.9 |
HIP 8700 |
17.30 |
| 2026-02-03 12:00 |
01:50:46.15 |
+17:07:34.6 |
HIP 8700 |
16.96 |
| 2026-02-04 00:00 |
01:50:47.64 |
+17:07:33.5 |
HIP 8700 |
16.60 |
| 2026-02-04 12:00 |
01:50:49.16 |
+17:07:32.7 |
HIP 8700 |
16.24 |
| 2026-02-05 00:00 |
01:50:50.72 |
+17:07:32.0 |
HIP 8700 |
15.87 |
| 2026-02-05 12:00 |
01:50:52.31 |
+17:07:31.6 |
HIP 8700 |
15.50 |
| 2026-02-06 00:00 |
01:50:53.95 |
+17:07:31.4 |
HIP 8700 |
15.11 |
| 2026-02-06 12:00 |
01:50:55.62 |
+17:07:31.4 |
HIP 8700 |
14.72 |
| 2026-02-07 00:00 |
01:50:57.32 |
+17:07:31.6 |
HIP 8700 |
14.32 |
| 2026-02-07 12:00 |
01:50:59.06 |
+17:07:32.1 |
HIP 8700 |
13.91 |
| 2026-02-08 00:00 |
01:51:00.84 |
+17:07:32.8 |
HIP 8700 |
13.50 |
| 2026-02-08 12:00 |
01:51:02.65 |
+17:07:33.7 |
HIP 8700 |
13.08 |
| 2026-02-09 00:00 |
01:51:04.50 |
+17:07:34.8 |
HIP 8700 |
12.65 |
| 2026-02-09 12:00 |
01:51:06.39 |
+17:07:36.1 |
HIP 8700 |
12.22 |
| 2026-02-10 00:00 |
01:51:08.31 |
+17:07:37.7 |
HIP 8700 |
11.78 |
| 2026-02-10 12:00 |
01:51:10.26 |
+17:07:39.4 |
HIP 8700 |
11.33 |
| 2026-02-11 00:00 |
01:51:12.26 |
+17:07:41.4 |
HIP 8700 |
10.88 |
| 2026-02-11 12:00 |
01:51:14.28 |
+17:07:43.6 |
HIP 8700 |
10.43 |
| 2026-02-12 00:00 |
01:51:16.34 |
+17:07:46.0 |
HIP 8700 |
9.97 |
| 2026-02-12 12:00 |
01:51:18.44 |
+17:07:48.7 |
HIP 8700 |
9.51 |
| 2026-02-13 00:00 |
01:51:20.57 |
+17:07:51.5 |
HIP 8700 |
9.04 |
| 2026-02-13 12:00 |
01:51:22.73 |
+17:07:54.6 |
HIP 8700 |
8.57 |
| 2026-02-14 00:00 |
01:51:24.93 |
+17:07:57.8 |
HIP 8700 |
8.11 |
| 2026-02-14 12:00 |
01:51:27.17 |
+17:08:01.3 |
HIP 8700 |
7.65 |
| 2026-02-15 00:00 |
01:51:29.43 |
+17:08:05.0 |
HIP 8700 |
7.19 |
| 2026-02-15 12:00 |
01:51:31.73 |
+17:08:08.9 |
HIP 8700 |
6.74 |
| 2026-02-16 00:00 |
01:51:34.07 |
+17:08:13.0 |
HIP 8700 |
6.30 |
| 2026-02-16 12:00 |
01:51:36.44 |
+17:08:17.4 |
HIP 8700 |
5.87 |
| 2026-02-17 00:00 |
01:51:38.84 |
+17:08:21.9 |
HIP 8700 |
5.47 |
| 2026-02-17 12:00 |
01:51:41.27 |
+17:08:26.7 |
HIP 8700 |
5.10 |
| 2026-02-18 00:00 |
01:51:43.74 |
+17:08:31.6 |
HIP 8700 |
4.78 |
| 2026-02-18 12:00 |
01:51:46.24 |
+17:08:36.8 |
HIP 8700 |
4.51 |
| 2026-02-19 00:00 |
01:51:48.77 |
+17:08:42.2 |
HIP 8700 |
4.30 |
| 2026-02-19 12:00 |
01:51:51.33 |
+17:08:47.7 |
HIP 8700 |
4.18 |
| 2026-02-20 00:00 |
01:51:53.93 |
+17:08:53.5 |
HIP 8700 |
4.15 |
| 2026-02-20 12:00 |
01:51:56.55 |
+17:08:59.5 |
HIP 8700 |
4.21 |
| 2026-02-21 00:00 |
01:51:59.21 |
+17:09:05.7 |
HIP 8700 |
4.38 |
| 2026-02-21 12:00 |
01:52:01.90 |
+17:09:12.1 |
HIP 8700 |
4.63 |
| 2026-02-22 00:00 |
01:52:04.62 |
+17:09:18.7 |
HIP 8700 |
4.96 |
| 2026-02-22 12:00 |
01:52:07.37 |
+17:09:25.4 |
HIP 8700 |
5.36 |
| 2026-02-23 00:00 |
01:52:10.15 |
+17:09:32.4 |
HIP 8700 |
5.82 |
| 2026-02-23 12:00 |
01:52:12.97 |
+17:09:39.6 |
HIP 8700 |
6.32 |
| 2026-02-24 00:00 |
01:52:15.81 |
+17:09:47.0 |
HIP 8700 |
6.86 |