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) |
| 2026-03-26 00:00 |
02:49:18.47 |
-05:34:47.7 |
HIP 13103 |
15.50 |
| 2026-03-26 12:00 |
02:49:22.02 |
-05:34:14.1 |
HIP 13103 |
16.54 |
| 2026-03-27 00:00 |
02:49:25.59 |
-05:33:40.6 |
HIP 13103 |
17.59 |
| 2026-03-27 12:00 |
02:49:29.18 |
-05:33:07.1 |
HIP 13103 |
18.64 |
| 2026-03-28 00:00 |
02:49:32.80 |
-05:32:33.8 |
HIP 13103 |
19.69 |
| 2026-03-28 12:00 |
02:49:36.44 |
-05:32:00.5 |
HIP 13103 |
20.75 |
| 2026-03-29 00:00 |
02:49:40.10 |
-05:31:27.4 |
HIP 13103 |
21.81 |
| 2026-03-29 12:00 |
02:49:43.78 |
-05:30:54.3 |
HIP 13103 |
22.88 |
| 2026-03-30 00:00 |
02:49:47.48 |
-05:30:21.4 |
HIP 13103 |
23.94 |
| 2026-03-30 12:00 |
02:49:51.20 |
-05:29:48.5 |
HIP 13135 |
24.02 |
| 2026-03-31 00:00 |
02:49:54.94 |
-05:29:15.8 |
HIP 13135 |
24.13 |
| 2026-03-31 12:00 |
02:49:58.71 |
-05:28:43.1 |
HIP 13135 |
24.29 |
| 2026-04-01 00:00 |
02:50:02.49 |
-05:28:10.6 |
HIP 13135 |
24.51 |
| 2026-04-01 12:00 |
02:50:06.29 |
-05:27:38.2 |
HIP 13135 |
24.78 |
| 2026-04-02 00:00 |
02:50:10.11 |
-05:27:05.8 |
HIP 13135 |
25.09 |
| 2026-04-02 12:00 |
02:50:13.95 |
-05:26:33.6 |
HIP 13135 |
25.45 |
| 2026-04-03 00:00 |
02:50:17.81 |
-05:26:01.5 |
HIP 13135 |
25.86 |
| 2026-04-03 12:00 |
02:50:21.68 |
-05:25:29.6 |
HIP 13233 |
26.31 |
| 2026-04-04 00:00 |
02:50:25.58 |
-05:24:57.7 |
HIP 13233 |
25.80 |
| 2026-04-04 12:00 |
02:50:29.49 |
-05:24:26.0 |
HIP 13233 |
25.33 |
| 2026-04-05 00:00 |
02:50:33.42 |
-05:23:54.3 |
HIP 13233 |
24.90 |
| 2026-04-05 12:00 |
02:50:37.37 |
-05:23:22.8 |
HIP 13233 |
24.52 |
| 2026-04-06 00:00 |
02:50:41.34 |
-05:22:51.5 |
HIP 13233 |
24.18 |
| 2026-04-06 12:00 |
02:50:45.32 |
-05:22:20.2 |
HIP 13233 |
23.90 |
| 2026-04-07 00:00 |
02:50:49.32 |
-05:21:49.1 |
HIP 13233 |
23.67 |
| 2026-04-07 12:00 |
02:50:53.34 |
-05:21:18.1 |
HIP 13233 |
23.50 |
| 2026-04-08 00:00 |
02:50:57.37 |
-05:20:47.2 |
HIP 13233 |
23.38 |
| 2026-04-08 12:00 |
02:51:01.42 |
-05:20:16.5 |
HIP 13233 |
23.32 |
| 2026-04-09 00:00 |
02:51:05.48 |
-05:19:45.9 |
HIP 13233 |
23.32 |
| 2026-04-09 12:00 |
02:51:09.56 |
-05:19:15.4 |
HIP 13233 |
23.37 |
| 2026-04-10 00:00 |
02:51:13.66 |
-05:18:45.1 |
HIP 13233 |
23.49 |
| 2026-04-10 12:00 |
02:51:17.77 |
-05:18:14.9 |
HIP 13233 |
23.66 |
| 2026-04-11 00:00 |
02:51:21.89 |
-05:17:44.9 |
HIP 13233 |
23.89 |
| 2026-04-11 12:00 |
02:51:26.03 |
-05:17:15.0 |
HIP 13233 |
24.18 |
| 2026-04-12 00:00 |
02:51:30.18 |
-05:16:45.2 |
HIP 13233 |
24.52 |
| 2026-04-12 12:00 |
02:51:34.35 |
-05:16:15.6 |
HIP 13451 |
24.52 |
| 2026-04-13 00:00 |
02:51:38.53 |
-05:15:46.1 |
HIP 13451 |
23.46 |
| 2026-04-13 12:00 |
02:51:42.72 |
-05:15:16.8 |
HIP 13451 |
22.41 |
| 2026-04-14 00:00 |
02:51:46.93 |
-05:14:47.7 |
HIP 13451 |
21.36 |
| 2026-04-14 12:00 |
02:51:51.15 |
-05:14:18.7 |
HIP 13451 |
20.32 |
| 2026-04-15 00:00 |
02:51:55.38 |
-05:13:49.8 |
HIP 13451 |
19.29 |
| 2026-04-15 12:00 |
02:51:59.62 |
-05:13:21.1 |
HIP 13451 |
18.27 |
| 2026-04-16 00:00 |
02:52:03.88 |
-05:12:52.6 |
HIP 13451 |
17.26 |