メタデータ
| 項目 |
値 |
| Designation |
C/2016 C2 (NEOWISE) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-04-19T14:19:31.131840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:23Z |
| Obs used |
148 |
| NEO |
- |
| M1 |
13.800 |
| K1 |
20.750 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2016-03-12.0000000 |
| e |
0.97563583 |
| q (au) |
1.559754 |
| a (au) |
64.018322 |
| i (deg) |
38.156610 |
| Ω (om, deg) |
24.404634 |
| ω (w, deg) |
214.403353 |
| M (ma, deg) |
359.925732 |
等級
散乱 + 全体線形
$$
M_a = (14.251 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
14.251 |
| n |
6.000 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
01:52:12.33 |
+16:52:15.9 |
HIP 8700 |
13.10 |
| 2026-09-20 12:00 |
01:52:08.34 |
+16:52:01.8 |
HIP 8700 |
13.08 |
| 2026-09-21 00:00 |
01:52:04.32 |
+16:51:47.6 |
HIP 8700 |
13.13 |
| 2026-09-21 12:00 |
01:52:00.28 |
+16:51:33.1 |
HIP 8700 |
13.26 |
| 2026-09-22 00:00 |
01:51:56.21 |
+16:51:18.5 |
HIP 8700 |
13.47 |
| 2026-09-22 12:00 |
01:51:52.12 |
+16:51:03.7 |
HIP 8700 |
13.75 |
| 2026-09-23 00:00 |
01:51:48.02 |
+16:50:48.7 |
HIP 8700 |
14.10 |
| 2026-09-23 12:00 |
01:51:43.89 |
+16:50:33.6 |
HIP 8700 |
14.52 |
| 2026-09-24 00:00 |
01:51:39.73 |
+16:50:18.3 |
HIP 8700 |
15.00 |
| 2026-09-24 12:00 |
01:51:35.56 |
+16:50:02.8 |
HIP 8700 |
15.53 |
| 2026-09-25 00:00 |
01:51:31.37 |
+16:49:47.1 |
HIP 8700 |
16.12 |
| 2026-09-25 12:00 |
01:51:27.15 |
+16:49:31.3 |
HIP 8700 |
16.76 |
| 2026-09-26 00:00 |
01:51:22.92 |
+16:49:15.3 |
HIP 8700 |
17.44 |
| 2026-09-26 12:00 |
01:51:18.66 |
+16:48:59.1 |
HIP 8700 |
18.16 |
| 2026-09-27 00:00 |
01:51:14.39 |
+16:48:42.8 |
HIP 8700 |
18.92 |
| 2026-09-27 12:00 |
01:51:10.09 |
+16:48:26.3 |
HIP 8700 |
19.71 |
| 2026-09-28 00:00 |
01:51:05.78 |
+16:48:09.7 |
HIP 8700 |
20.52 |
| 2026-09-28 12:00 |
01:51:01.45 |
+16:47:52.8 |
HIP 8700 |
21.37 |
| 2026-09-29 00:00 |
01:50:57.10 |
+16:47:35.9 |
HIP 8700 |
22.24 |
| 2026-09-29 12:00 |
01:50:52.73 |
+16:47:18.7 |
HIP 8700 |
23.13 |
| 2026-09-30 00:00 |
01:50:48.35 |
+16:47:01.5 |
HIP 8700 |
24.04 |
| 2026-09-30 12:00 |
01:50:43.95 |
+16:46:44.0 |
HIP 8700 |
24.98 |
| 2026-10-01 00:00 |
01:50:39.53 |
+16:46:26.4 |
HIP 8700 |
25.92 |
| 2026-10-01 12:00 |
01:50:35.10 |
+16:46:08.7 |
HIP 8667 |
26.88 |
| 2026-10-02 00:00 |
01:50:30.64 |
+16:45:50.8 |
HIP 8667 |
27.25 |
| 2026-10-02 12:00 |
01:50:26.18 |
+16:45:32.7 |
HIP 8667 |
27.66 |
| 2026-10-03 00:00 |
01:50:21.70 |
+16:45:14.5 |
HIP 8667 |
28.12 |
| 2026-10-03 12:00 |
01:50:17.20 |
+16:44:56.2 |
HIP 8667 |
28.61 |
| 2026-10-04 00:00 |
01:50:12.69 |
+16:44:37.7 |
HIP 8448 |
28.87 |
| 2026-10-04 12:00 |
01:50:08.16 |
+16:44:19.1 |
HIP 8448 |
27.94 |
| 2026-10-05 00:00 |
01:50:03.62 |
+16:44:00.3 |
HIP 8448 |
27.02 |
| 2026-10-05 12:00 |
01:49:59.07 |
+16:43:41.4 |
HIP 8448 |
26.11 |
| 2026-10-06 00:00 |
01:49:54.50 |
+16:43:22.4 |
HIP 8448 |
25.21 |
| 2026-10-06 12:00 |
01:49:49.92 |
+16:43:03.2 |
HIP 8448 |
24.34 |
| 2026-10-07 00:00 |
01:49:45.33 |
+16:42:43.9 |
HIP 8448 |
23.48 |
| 2026-10-07 12:00 |
01:49:40.72 |
+16:42:24.5 |
HIP 8448 |
22.64 |
| 2026-10-08 00:00 |
01:49:36.11 |
+16:42:04.9 |
HIP 8448 |
21.83 |
| 2026-10-08 12:00 |
01:49:31.48 |
+16:41:45.2 |
HIP 8448 |
21.05 |
| 2026-10-09 00:00 |
01:49:26.84 |
+16:41:25.4 |
HIP 8448 |
20.31 |
| 2026-10-09 12:00 |
01:49:22.20 |
+16:41:05.4 |
HIP 8448 |
19.59 |
| 2026-10-10 00:00 |
01:49:17.54 |
+16:40:45.3 |
HIP 8448 |
18.93 |
| 2026-10-10 12:00 |
01:49:12.87 |
+16:40:25.1 |
HIP 8448 |
18.30 |
| 2026-10-11 00:00 |
01:49:08.20 |
+16:40:04.8 |
HIP 8448 |
17.73 |