C/2018 N1 (NEOWISE)
メタデータ
| 項目 |
値 |
| Designation |
C/2018 N1 (NEOWISE) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-08-01T23:35:12.114240Z |
| Orbit solution date (soln_date, UTC) |
2022-06-20T23:12:32Z |
| Obs used |
263 |
| NEO |
- |
| M1 |
14.800 |
| K1 |
11.750 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-07-02T08:53:36.384000Z |
| Discovery magnitude (MPC) |
16.00 R |
| Discovery observatory (MPC) |
C51 · WISE |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-07-23.0000000 |
| e |
0.99690168 |
| q (au) |
1.307382 |
| a (au) |
421.964782 |
| i (deg) |
159.444331 |
| Ω (om, deg) |
292.438182 |
| ω (w, deg) |
354.558421 |
| M (ma, deg) |
359.998865 |
等級
散乱 + 全体線形
$$
M_a = (13.856 + 5.455\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.856 |
| n |
5.455 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.957 |
| δ90 |
1.000 |
| 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 |
| 2017-12-15 |
2018-08-01 |
+5.8573 |
-2.511 |
| 2018-08-02 |
2018-10-06 |
-17.1024 |
-0.661 |
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 |
10:10:13.17 |
+24:11:25.3 |
HIP 49842 |
19.29 |
| 2026-02-03 12:00 |
10:10:06.51 |
+24:12:02.4 |
HIP 49842 |
20.35 |
| 2026-02-04 00:00 |
10:09:59.83 |
+24:12:39.4 |
HIP 49842 |
21.48 |
| 2026-02-04 12:00 |
10:09:53.14 |
+24:13:16.2 |
HIP 49677 |
20.12 |
| 2026-02-05 00:00 |
10:09:46.43 |
+24:13:53.0 |
HIP 49677 |
18.48 |
| 2026-02-05 12:00 |
10:09:39.71 |
+24:14:29.6 |
HIP 49677 |
16.84 |
| 2026-02-06 00:00 |
10:09:32.97 |
+24:15:06.1 |
HIP 49677 |
15.21 |
| 2026-02-06 12:00 |
10:09:26.22 |
+24:15:42.4 |
HIP 49677 |
13.58 |
| 2026-02-07 00:00 |
10:09:19.46 |
+24:16:18.7 |
HIP 49677 |
11.95 |
| 2026-02-07 12:00 |
10:09:12.68 |
+24:16:54.7 |
HIP 49677 |
10.32 |
| 2026-02-08 00:00 |
10:09:05.89 |
+24:17:30.7 |
HIP 49677 |
8.71 |
| 2026-02-08 12:00 |
10:08:59.10 |
+24:18:06.5 |
HIP 49677 |
7.11 |
| 2026-02-09 00:00 |
10:08:52.29 |
+24:18:42.1 |
HIP 49677 |
5.55 |
| 2026-02-09 12:00 |
10:08:45.47 |
+24:19:17.6 |
HIP 49677 |
4.06 |
| 2026-02-10 00:00 |
10:08:38.64 |
+24:19:53.0 |
HIP 49677 |
2.79 |
| 2026-02-10 12:00 |
10:08:31.80 |
+24:20:28.1 |
HIP 49677 |
2.13 |
| 2026-02-11 00:00 |
10:08:24.96 |
+24:21:03.2 |
HIP 49677 |
2.61 |
| 2026-02-11 12:00 |
10:08:18.10 |
+24:21:38.0 |
HIP 49677 |
3.83 |
| 2026-02-12 00:00 |
10:08:11.24 |
+24:22:12.7 |
HIP 49677 |
5.30 |
| 2026-02-12 12:00 |
10:08:04.38 |
+24:22:47.2 |
HIP 49677 |
6.85 |
| 2026-02-13 00:00 |
10:07:57.50 |
+24:23:21.5 |
HIP 49677 |
8.45 |
| 2026-02-13 12:00 |
10:07:50.62 |
+24:23:55.7 |
HIP 49677 |
10.07 |
| 2026-02-14 00:00 |
10:07:43.74 |
+24:24:29.7 |
HIP 49677 |
11.70 |
| 2026-02-14 12:00 |
10:07:36.85 |
+24:25:03.5 |
HIP 49677 |
13.34 |
| 2026-02-15 00:00 |
10:07:29.96 |
+24:25:37.1 |
HIP 49677 |
14.99 |
| 2026-02-15 12:00 |
10:07:23.07 |
+24:26:10.5 |
HIP 49677 |
16.64 |
| 2026-02-16 00:00 |
10:07:16.17 |
+24:26:43.8 |
HIP 49677 |
18.29 |
| 2026-02-16 12:00 |
10:07:09.27 |
+24:27:16.8 |
HIP 49677 |
19.94 |
| 2026-02-17 00:00 |
10:07:02.37 |
+24:27:49.6 |
HIP 49677 |
21.59 |
| 2026-02-17 12:00 |
10:06:55.47 |
+24:28:22.3 |
HIP 49677 |
23.24 |
| 2026-02-18 00:00 |
10:06:48.57 |
+24:28:54.7 |
HIP 49677 |
24.89 |
| 2026-02-18 12:00 |
10:06:41.67 |
+24:29:26.9 |
HIP 49430 |
26.19 |
| 2026-02-19 00:00 |
10:06:34.77 |
+24:29:58.9 |
HIP 49430 |
24.78 |
| 2026-02-19 12:00 |
10:06:27.88 |
+24:30:30.7 |
HIP 49430 |
23.41 |
| 2026-02-20 00:00 |
10:06:20.98 |
+24:31:02.3 |
HIP 49430 |
22.07 |
| 2026-02-20 12:00 |
10:06:14.09 |
+24:31:33.7 |
HIP 49430 |
20.79 |
| 2026-02-21 00:00 |
10:06:07.20 |
+24:32:04.8 |
HIP 49430 |
19.57 |
| 2026-02-21 12:00 |
10:06:00.32 |
+24:32:35.7 |
HIP 49430 |
18.41 |
| 2026-02-22 00:00 |
10:05:53.44 |
+24:33:06.4 |
HIP 49430 |
17.34 |
| 2026-02-22 12:00 |
10:05:46.57 |
+24:33:36.9 |
HIP 49430 |
16.37 |
| 2026-02-23 00:00 |
10:05:39.70 |
+24:34:07.1 |
HIP 49430 |
15.52 |
| 2026-02-23 12:00 |
10:05:32.84 |
+24:34:37.1 |
HIP 49430 |
14.80 |
| 2026-02-24 00:00 |
10:05:25.99 |
+24:35:06.8 |
HIP 49430 |
14.24 |