C/2015 YG1 (NEOWISE)
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) |
| 2026-02-03 00:00 |
14:13:44.77 |
-73:41:49.2 |
HIP 69451 |
16.42 |
| 2026-02-03 12:00 |
14:13:43.26 |
-73:43:09.1 |
HIP 69451 |
17.73 |
| 2026-02-04 00:00 |
14:13:41.59 |
-73:44:28.9 |
HIP 69451 |
19.03 |
| 2026-02-04 12:00 |
14:13:39.73 |
-73:45:48.5 |
HIP 69451 |
20.34 |
| 2026-02-05 00:00 |
14:13:37.71 |
-73:47:07.9 |
HIP 69451 |
21.64 |
| 2026-02-05 12:00 |
14:13:35.50 |
-73:48:27.0 |
HIP 69313 |
22.05 |
| 2026-02-06 00:00 |
14:13:33.12 |
-73:49:45.9 |
HIP 69313 |
20.80 |
| 2026-02-06 12:00 |
14:13:30.56 |
-73:51:04.6 |
HIP 69313 |
19.55 |
| 2026-02-07 00:00 |
14:13:27.82 |
-73:52:23.1 |
HIP 69313 |
18.32 |
| 2026-02-07 12:00 |
14:13:24.91 |
-73:53:41.3 |
HIP 69313 |
17.10 |
| 2026-02-08 00:00 |
14:13:21.81 |
-73:54:59.3 |
HIP 69313 |
15.89 |
| 2026-02-08 12:00 |
14:13:18.54 |
-73:56:17.0 |
HIP 69313 |
14.69 |
| 2026-02-09 00:00 |
14:13:15.09 |
-73:57:34.5 |
HIP 69313 |
13.51 |
| 2026-02-09 12:00 |
14:13:11.45 |
-73:58:51.7 |
HIP 69313 |
12.36 |
| 2026-02-10 00:00 |
14:13:07.64 |
-74:00:08.6 |
HIP 69313 |
11.23 |
| 2026-02-10 12:00 |
14:13:03.64 |
-74:01:25.3 |
HIP 69313 |
10.14 |
| 2026-02-11 00:00 |
14:12:59.46 |
-74:02:41.7 |
HIP 69313 |
9.11 |
| 2026-02-11 12:00 |
14:12:55.10 |
-74:03:57.8 |
HIP 69313 |
8.14 |
| 2026-02-12 00:00 |
14:12:50.56 |
-74:05:13.6 |
HIP 69313 |
7.27 |
| 2026-02-12 12:00 |
14:12:45.83 |
-74:06:29.1 |
HIP 69313 |
6.54 |
| 2026-02-13 00:00 |
14:12:40.93 |
-74:07:44.3 |
HIP 69313 |
5.99 |
| 2026-02-13 12:00 |
14:12:35.84 |
-74:08:59.1 |
HIP 69313 |
5.67 |
| 2026-02-14 00:00 |
14:12:30.56 |
-74:10:13.7 |
HIP 69313 |
5.63 |
| 2026-02-14 12:00 |
14:12:25.10 |
-74:11:27.9 |
HIP 69313 |
5.87 |
| 2026-02-15 00:00 |
14:12:19.46 |
-74:12:41.8 |
HIP 69313 |
6.35 |
| 2026-02-15 12:00 |
14:12:13.64 |
-74:13:55.4 |
HIP 69313 |
7.03 |
| 2026-02-16 00:00 |
14:12:07.63 |
-74:15:08.6 |
HIP 69313 |
7.85 |
| 2026-02-16 12:00 |
14:12:01.44 |
-74:16:21.5 |
HIP 69313 |
8.78 |
| 2026-02-17 00:00 |
14:11:55.06 |
-74:17:34.0 |
HIP 69313 |
9.78 |
| 2026-02-17 12:00 |
14:11:48.50 |
-74:18:46.1 |
HIP 69204 |
10.37 |
| 2026-02-18 00:00 |
14:11:41.75 |
-74:19:57.9 |
HIP 69204 |
9.18 |
| 2026-02-18 12:00 |
14:11:34.82 |
-74:21:09.3 |
HIP 69204 |
8.01 |
| 2026-02-19 00:00 |
14:11:27.71 |
-74:22:20.3 |
HIP 69204 |
6.88 |
| 2026-02-19 12:00 |
14:11:20.41 |
-74:23:30.9 |
HIP 69204 |
5.80 |
| 2026-02-20 00:00 |
14:11:12.93 |
-74:24:41.1 |
HIP 69204 |
4.80 |
| 2026-02-20 12:00 |
14:11:05.27 |
-74:25:50.9 |
HIP 69204 |
3.97 |
| 2026-02-21 00:00 |
14:10:57.42 |
-74:27:00.3 |
HIP 69204 |
3.40 |
| 2026-02-21 12:00 |
14:10:49.39 |
-74:28:09.3 |
HIP 69204 |
3.24 |
| 2026-02-22 00:00 |
14:10:41.18 |
-74:29:17.9 |
HIP 69204 |
3.55 |
| 2026-02-22 12:00 |
14:10:32.78 |
-74:30:26.0 |
HIP 69204 |
4.22 |
| 2026-02-23 00:00 |
14:10:24.20 |
-74:31:33.7 |
HIP 69204 |
5.11 |
| 2026-02-23 12:00 |
14:10:15.45 |
-74:32:41.0 |
HIP 69204 |
6.13 |
| 2026-02-24 00:00 |
14:10:06.51 |
-74:33:47.8 |
HIP 69204 |
7.22 |