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) |
| 2026-06-01 00:00 |
13:14:59.28 |
-74:37:41.9 |
HIP 64972 |
20.28 |
| 2026-06-01 12:00 |
13:14:47.23 |
-74:36:39.3 |
HIP 64972 |
21.56 |
| 2026-06-02 00:00 |
13:14:35.35 |
-74:35:36.4 |
HIP 64972 |
22.84 |
| 2026-06-02 12:00 |
13:14:23.63 |
-74:34:33.1 |
HIP 64972 |
24.12 |
| 2026-06-03 00:00 |
13:14:12.07 |
-74:33:29.5 |
HIP 64972 |
25.40 |
| 2026-06-03 12:00 |
13:14:00.68 |
-74:32:25.5 |
HIP 64972 |
26.69 |
| 2026-06-04 00:00 |
13:13:49.44 |
-74:31:21.2 |
HIP 64972 |
27.97 |
| 2026-06-04 12:00 |
13:13:38.38 |
-74:30:16.5 |
HIP 64531 |
28.98 |
| 2026-06-05 00:00 |
13:13:27.47 |
-74:29:11.5 |
HIP 64531 |
27.91 |
| 2026-06-05 12:00 |
13:13:16.73 |
-74:28:06.1 |
HIP 64531 |
26.84 |
| 2026-06-06 00:00 |
13:13:06.16 |
-74:27:00.5 |
HIP 64531 |
25.80 |
| 2026-06-06 12:00 |
13:12:55.75 |
-74:25:54.5 |
HIP 64531 |
24.77 |
| 2026-06-07 00:00 |
13:12:45.51 |
-74:24:48.2 |
HIP 64531 |
23.76 |
| 2026-06-07 12:00 |
13:12:35.44 |
-74:23:41.6 |
HIP 64531 |
22.78 |
| 2026-06-08 00:00 |
13:12:25.53 |
-74:22:34.8 |
HIP 64531 |
21.82 |
| 2026-06-08 12:00 |
13:12:15.79 |
-74:21:27.6 |
HIP 64531 |
20.90 |
| 2026-06-09 00:00 |
13:12:06.22 |
-74:20:20.1 |
HIP 64531 |
20.01 |
| 2026-06-09 12:00 |
13:11:56.81 |
-74:19:12.4 |
HIP 64531 |
19.15 |
| 2026-06-10 00:00 |
13:11:47.58 |
-74:18:04.4 |
HIP 64531 |
18.35 |
| 2026-06-10 12:00 |
13:11:38.51 |
-74:16:56.2 |
HIP 64531 |
17.59 |
| 2026-06-11 00:00 |
13:11:29.61 |
-74:15:47.7 |
HIP 64531 |
16.89 |
| 2026-06-11 12:00 |
13:11:20.88 |
-74:14:38.9 |
HIP 64531 |
16.25 |
| 2026-06-12 00:00 |
13:11:12.32 |
-74:13:30.0 |
HIP 64531 |
15.68 |
| 2026-06-12 12:00 |
13:11:03.94 |
-74:12:20.7 |
HIP 64531 |
15.19 |
| 2026-06-13 00:00 |
13:10:55.72 |
-74:11:11.3 |
HIP 64531 |
14.79 |
| 2026-06-13 12:00 |
13:10:47.67 |
-74:10:01.7 |
HIP 64531 |
14.48 |
| 2026-06-14 00:00 |
13:10:39.79 |
-74:08:51.8 |
HIP 64531 |
14.27 |
| 2026-06-14 12:00 |
13:10:32.08 |
-74:07:41.7 |
HIP 64531 |
14.16 |
| 2026-06-15 00:00 |
13:10:24.55 |
-74:06:31.5 |
HIP 64531 |
14.16 |
| 2026-06-15 12:00 |
13:10:17.18 |
-74:05:21.0 |
HIP 64531 |
14.26 |
| 2026-06-16 00:00 |
13:10:09.99 |
-74:04:10.4 |
HIP 64531 |
14.46 |
| 2026-06-16 12:00 |
13:10:02.97 |
-74:02:59.6 |
HIP 64531 |
14.76 |
| 2026-06-17 00:00 |
13:09:56.11 |
-74:01:48.7 |
HIP 64531 |
15.15 |
| 2026-06-17 12:00 |
13:09:49.43 |
-74:00:37.6 |
HIP 64531 |
15.63 |
| 2026-06-18 00:00 |
13:09:42.92 |
-73:59:26.3 |
HIP 64531 |
16.18 |
| 2026-06-18 12:00 |
13:09:36.58 |
-73:58:14.9 |
HIP 64531 |
16.79 |
| 2026-06-19 00:00 |
13:09:30.41 |
-73:57:03.4 |
HIP 64531 |
17.47 |
| 2026-06-19 12:00 |
13:09:24.42 |
-73:55:51.7 |
HIP 64531 |
18.20 |
| 2026-06-20 00:00 |
13:09:18.59 |
-73:54:39.9 |
HIP 64531 |
18.98 |
| 2026-06-20 12:00 |
13:09:12.93 |
-73:53:28.0 |
HIP 64047 |
19.57 |
| 2026-06-21 00:00 |
13:09:07.44 |
-73:52:16.0 |
HIP 64047 |
18.31 |
| 2026-06-21 12:00 |
13:09:02.12 |
-73:51:03.9 |
HIP 64047 |
17.06 |
| 2026-06-22 00:00 |
13:08:56.97 |
-73:49:51.7 |
HIP 64047 |
15.81 |