メタデータ
| 項目 |
値 |
| Designation |
C/2016 U1 (NEOWISE) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-01-14T00:24:03.925440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:28Z |
| Obs used |
366 |
| NEO |
- |
| M1 |
13.100 |
| K1 |
12.250 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2016-12-12.0000000 |
| e |
1.00025297 |
| q (au) |
0.319170 |
| a (au) |
-1261.677714 |
| i (deg) |
46.434833 |
| Ω (om, deg) |
61.428521 |
| ω (w, deg) |
162.748270 |
| M (ma, deg) |
-0.000726 |
等級
散乱 + 全体線形
$$
M_a = (15.005 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
15.005 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.984 |
| k |
0.993 |
| δ90 |
9.928 |
| 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 |
| 2016-10-21 |
2017-01-12 |
-0.0100 |
-1.052 |
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) |
| 2026-09-20 00:00 |
03:02:23.68 |
-05:44:35.3 |
HIP 14241 |
19.25 |
| 2026-09-20 12:00 |
03:02:20.75 |
-05:45:06.6 |
HIP 14241 |
20.08 |
| 2026-09-21 00:00 |
03:02:17.80 |
-05:45:37.8 |
HIP 14241 |
20.93 |
| 2026-09-21 12:00 |
03:02:14.82 |
-05:46:09.1 |
HIP 14241 |
21.79 |
| 2026-09-22 00:00 |
03:02:11.80 |
-05:46:40.2 |
HIP 14241 |
22.66 |
| 2026-09-22 12:00 |
03:02:08.75 |
-05:47:11.4 |
HIP 14241 |
23.54 |
| 2026-09-23 00:00 |
03:02:05.67 |
-05:47:42.5 |
HIP 14241 |
24.42 |
| 2026-09-23 12:00 |
03:02:02.57 |
-05:48:13.6 |
HIP 14241 |
25.32 |
| 2026-09-24 00:00 |
03:01:59.43 |
-05:48:44.7 |
HIP 14241 |
26.23 |
| 2026-09-24 12:00 |
03:01:56.26 |
-05:49:15.7 |
HIP 14241 |
27.15 |
| 2026-09-25 00:00 |
03:01:53.07 |
-05:49:46.6 |
HIP 14241 |
28.07 |
| 2026-09-25 12:00 |
03:01:49.84 |
-05:50:17.6 |
HIP 13996 |
28.31 |
| 2026-09-26 00:00 |
03:01:46.58 |
-05:50:48.4 |
HIP 13996 |
27.35 |
| 2026-09-26 12:00 |
03:01:43.30 |
-05:51:19.2 |
HIP 13996 |
26.39 |
| 2026-09-27 00:00 |
03:01:39.99 |
-05:51:50.0 |
HIP 13996 |
25.42 |
| 2026-09-27 12:00 |
03:01:36.65 |
-05:52:20.7 |
HIP 13996 |
24.44 |
| 2026-09-28 00:00 |
03:01:33.28 |
-05:52:51.4 |
HIP 13996 |
23.46 |
| 2026-09-28 12:00 |
03:01:29.88 |
-05:53:21.9 |
HIP 13996 |
22.47 |
| 2026-09-29 00:00 |
03:01:26.46 |
-05:53:52.5 |
HIP 13996 |
21.48 |
| 2026-09-29 12:00 |
03:01:23.00 |
-05:54:22.9 |
HIP 13996 |
20.48 |
| 2026-09-30 00:00 |
03:01:19.52 |
-05:54:53.3 |
HIP 13996 |
19.48 |
| 2026-09-30 12:00 |
03:01:16.02 |
-05:55:23.6 |
HIP 13996 |
18.47 |
| 2026-10-01 00:00 |
03:01:12.49 |
-05:55:53.9 |
HIP 13996 |
17.46 |
| 2026-10-01 12:00 |
03:01:08.93 |
-05:56:24.0 |
HIP 13996 |
16.44 |
| 2026-10-02 00:00 |
03:01:05.34 |
-05:56:54.1 |
HIP 13996 |
15.42 |
| 2026-10-02 12:00 |
03:01:01.73 |
-05:57:24.1 |
HIP 13996 |
14.39 |
| 2026-10-03 00:00 |
03:00:58.09 |
-05:57:54.0 |
HIP 13996 |
13.36 |
| 2026-10-03 12:00 |
03:00:54.43 |
-05:58:23.8 |
HIP 13996 |
12.32 |
| 2026-10-04 00:00 |
03:00:50.74 |
-05:58:53.6 |
HIP 13996 |
11.28 |
| 2026-10-04 12:00 |
03:00:47.03 |
-05:59:23.2 |
HIP 13996 |
10.23 |
| 2026-10-05 00:00 |
03:00:43.29 |
-05:59:52.8 |
HIP 13996 |
9.19 |
| 2026-10-05 12:00 |
03:00:39.53 |
-06:00:22.2 |
HIP 13996 |
8.13 |
| 2026-10-06 00:00 |
03:00:35.74 |
-06:00:51.6 |
HIP 13996 |
7.07 |
| 2026-10-06 12:00 |
03:00:31.93 |
-06:01:20.8 |
HIP 13996 |
6.01 |
| 2026-10-07 00:00 |
03:00:28.09 |
-06:01:50.0 |
HIP 13996 |
4.95 |
| 2026-10-07 12:00 |
03:00:24.24 |
-06:02:19.0 |
HIP 13996 |
3.89 |
| 2026-10-08 00:00 |
03:00:20.36 |
-06:02:47.9 |
HIP 13996 |
2.84 |
| 2026-10-08 12:00 |
03:00:16.45 |
-06:03:16.7 |
HIP 13996 |
1.82 |
| 2026-10-09 00:00 |
03:00:12.53 |
-06:03:45.4 |
HIP 13996 |
0.94 |
| 2026-10-09 12:00 |
03:00:08.58 |
-06:04:13.9 |
HIP 13996 |
0.91 |
| 2026-10-10 00:00 |
03:00:04.61 |
-06:04:42.4 |
HIP 13996 |
1.78 |
| 2026-10-10 12:00 |
03:00:00.62 |
-06:05:10.7 |
HIP 13996 |
2.82 |
| 2026-10-11 00:00 |
02:59:56.61 |
-06:05:38.9 |
HIP 13996 |
3.89 |