メタデータ
| 項目 |
値 |
| Designation |
C/2015 YG1 (NEOWISE) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-09-28T23:19:05.626560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:21Z |
| Obs used |
222 |
| NEO |
- |
| M1 |
12.100 |
| K1 |
10.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2016-02-05.0000000 |
| e |
0.87923622 |
| q (au) |
2.073411 |
| a (au) |
17.169149 |
| i (deg) |
57.336038 |
| Ω (om, deg) |
350.511863 |
| ω (w, deg) |
102.791763 |
| M (ma, deg) |
1.787583 |
等級
散乱 + 全体線形
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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 |
13:29:58.12 |
-71:13:50.4 |
HIP 65784 |
14.84 |
| 2026-09-20 12:00 |
13:30:13.48 |
-71:13:37.9 |
HIP 65784 |
15.40 |
| 2026-09-21 00:00 |
13:30:28.88 |
-71:13:25.8 |
HIP 65784 |
16.04 |
| 2026-09-21 12:00 |
13:30:44.34 |
-71:13:14.4 |
HIP 65784 |
16.75 |
| 2026-09-22 00:00 |
13:30:59.84 |
-71:13:03.4 |
HIP 65784 |
17.50 |
| 2026-09-22 12:00 |
13:31:15.39 |
-71:12:53.0 |
HIP 65784 |
18.31 |
| 2026-09-23 00:00 |
13:31:30.99 |
-71:12:43.2 |
HIP 65784 |
19.16 |
| 2026-09-23 12:00 |
13:31:46.63 |
-71:12:33.9 |
HIP 65784 |
20.05 |
| 2026-09-24 00:00 |
13:32:02.32 |
-71:12:25.2 |
HIP 65784 |
20.97 |
| 2026-09-24 12:00 |
13:32:18.05 |
-71:12:17.0 |
HIP 66038 |
21.45 |
| 2026-09-25 00:00 |
13:32:33.82 |
-71:12:09.3 |
HIP 66038 |
21.61 |
| 2026-09-25 12:00 |
13:32:49.63 |
-71:12:02.2 |
HIP 66038 |
21.83 |
| 2026-09-26 00:00 |
13:33:05.49 |
-71:11:55.7 |
HIP 66038 |
22.11 |
| 2026-09-26 12:00 |
13:33:21.39 |
-71:11:49.6 |
HIP 66038 |
22.46 |
| 2026-09-27 00:00 |
13:33:37.33 |
-71:11:44.2 |
HIP 66038 |
22.86 |
| 2026-09-27 12:00 |
13:33:53.31 |
-71:11:39.2 |
HIP 66038 |
23.32 |
| 2026-09-28 00:00 |
13:34:09.33 |
-71:11:34.9 |
HIP 66038 |
23.83 |
| 2026-09-28 12:00 |
13:34:25.39 |
-71:11:31.0 |
HIP 66038 |
24.40 |
| 2026-09-29 00:00 |
13:34:41.49 |
-71:11:27.7 |
HIP 66038 |
25.00 |
| 2026-09-29 12:00 |
13:34:57.62 |
-71:11:25.0 |
HIP 66038 |
25.66 |
| 2026-09-30 00:00 |
13:35:13.80 |
-71:11:22.8 |
HIP 66038 |
26.35 |
| 2026-09-30 12:00 |
13:35:30.00 |
-71:11:21.1 |
HIP 66038 |
27.08 |
| 2026-10-01 00:00 |
13:35:46.25 |
-71:11:20.0 |
HIP 66038 |
27.85 |
| 2026-10-01 12:00 |
13:36:02.53 |
-71:11:19.5 |
HIP 66038 |
28.64 |
| 2026-10-02 00:00 |
13:36:18.85 |
-71:11:19.4 |
HIP 66038 |
29.47 |
| 2026-10-02 12:00 |
13:36:35.20 |
-71:11:20.0 |
HIP 66668 |
29.31 |
| 2026-10-03 00:00 |
13:36:51.58 |
-71:11:21.0 |
HIP 66668 |
28.58 |
| 2026-10-03 12:00 |
13:37:08.00 |
-71:11:22.7 |
HIP 66668 |
27.91 |
| 2026-10-04 00:00 |
13:37:24.45 |
-71:11:24.8 |
HIP 66668 |
27.29 |
| 2026-10-04 12:00 |
13:37:40.93 |
-71:11:27.5 |
HIP 66668 |
26.73 |
| 2026-10-05 00:00 |
13:37:57.44 |
-71:11:30.8 |
HIP 66668 |
26.24 |
| 2026-10-05 12:00 |
13:38:13.98 |
-71:11:34.6 |
HIP 66668 |
25.81 |
| 2026-10-06 00:00 |
13:38:30.55 |
-71:11:38.9 |
HIP 66668 |
25.46 |
| 2026-10-06 12:00 |
13:38:47.16 |
-71:11:43.8 |
HIP 66668 |
25.18 |
| 2026-10-07 00:00 |
13:39:03.79 |
-71:11:49.3 |
HIP 66668 |
24.99 |
| 2026-10-07 12:00 |
13:39:20.44 |
-71:11:55.3 |
HIP 66668 |
24.87 |
| 2026-10-08 00:00 |
13:39:37.13 |
-71:12:01.8 |
HIP 66668 |
24.84 |
| 2026-10-08 12:00 |
13:39:53.84 |
-71:12:08.9 |
HIP 66668 |
24.89 |
| 2026-10-09 00:00 |
13:40:10.57 |
-71:12:16.5 |
HIP 66668 |
25.02 |
| 2026-10-09 12:00 |
13:40:27.33 |
-71:12:24.7 |
HIP 66668 |
25.24 |
| 2026-10-10 00:00 |
13:40:44.11 |
-71:12:33.4 |
HIP 66668 |
25.54 |
| 2026-10-10 12:00 |
13:41:00.92 |
-71:12:42.7 |
HIP 66668 |
25.91 |
| 2026-10-11 00:00 |
13:41:17.75 |
-71:12:52.5 |
HIP 66668 |
26.37 |