メタデータ
| 項目 |
値 |
| Designation |
C/2015 X8 (NEOWISE) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-10-23T02:58:51.087360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:20Z |
| Obs used |
116 |
| NEO |
Yes |
| M1 |
16.200 |
| K1 |
4.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2016-01-22.0000000 |
| e |
0.93911400 |
| q (au) |
1.190273 |
| a (au) |
19.549200 |
| i (deg) |
155.281698 |
| Ω (om, deg) |
191.111870 |
| ω (w, deg) |
20.400527 |
| M (ma, deg) |
1.036236 |
等級
散乱 + 全体線形
$$
M_a = (15.395 + 4.524\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
15.395 |
| n |
4.524 |
| gf |
0.999 |
| gb |
-0.984 |
| k |
0.971 |
| δ90 |
10.000 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
00:40:08.73 |
+03:08:15.4 |
HIP 3086 |
13.96 |
| 2026-05-12 12:00 |
00:40:12.14 |
+03:08:33.6 |
HIP 3086 |
14.82 |
| 2026-05-13 00:00 |
00:40:15.52 |
+03:08:51.7 |
HIP 3086 |
15.68 |
| 2026-05-13 12:00 |
00:40:18.88 |
+03:09:09.6 |
HIP 3086 |
16.54 |
| 2026-05-14 00:00 |
00:40:22.22 |
+03:09:27.3 |
HIP 3086 |
17.39 |
| 2026-05-14 12:00 |
00:40:25.53 |
+03:09:44.8 |
HIP 3086 |
18.24 |
| 2026-05-15 00:00 |
00:40:28.81 |
+03:10:02.2 |
HIP 3086 |
19.08 |
| 2026-05-15 12:00 |
00:40:32.06 |
+03:10:19.4 |
HIP 3086 |
19.92 |
| 2026-05-16 00:00 |
00:40:35.29 |
+03:10:36.4 |
HIP 3086 |
20.76 |
| 2026-05-16 12:00 |
00:40:38.49 |
+03:10:53.2 |
HIP 3086 |
21.58 |
| 2026-05-17 00:00 |
00:40:41.67 |
+03:11:09.8 |
HIP 3086 |
22.41 |
| 2026-05-17 12:00 |
00:40:44.82 |
+03:11:26.2 |
HIP 3086 |
23.22 |
| 2026-05-18 00:00 |
00:40:47.94 |
+03:11:42.5 |
HIP 3086 |
24.04 |
| 2026-05-18 12:00 |
00:40:51.03 |
+03:11:58.5 |
HIP 3086 |
24.84 |
| 2026-05-19 00:00 |
00:40:54.09 |
+03:12:14.4 |
HIP 3086 |
25.64 |
| 2026-05-19 12:00 |
00:40:57.13 |
+03:12:30.0 |
HIP 3086 |
26.43 |
| 2026-05-20 00:00 |
00:41:00.13 |
+03:12:45.5 |
HIP 3086 |
27.21 |
| 2026-05-20 12:00 |
00:41:03.11 |
+03:13:00.8 |
HIP 3276 |
27.71 |
| 2026-05-21 00:00 |
00:41:06.06 |
+03:13:15.9 |
HIP 3276 |
27.20 |
| 2026-05-21 12:00 |
00:41:08.98 |
+03:13:30.7 |
HIP 3276 |
26.71 |
| 2026-05-22 00:00 |
00:41:11.87 |
+03:13:45.4 |
HIP 3276 |
26.23 |
| 2026-05-22 12:00 |
00:41:14.73 |
+03:14:00.0 |
HIP 3276 |
25.78 |
| 2026-05-23 00:00 |
00:41:17.56 |
+03:14:14.2 |
HIP 3276 |
25.35 |
| 2026-05-23 12:00 |
00:41:20.36 |
+03:14:28.3 |
HIP 3276 |
24.93 |
| 2026-05-24 00:00 |
00:41:23.13 |
+03:14:42.1 |
HIP 3276 |
24.54 |
| 2026-05-24 12:00 |
00:41:25.87 |
+03:14:55.8 |
HIP 3276 |
24.16 |
| 2026-05-25 00:00 |
00:41:28.57 |
+03:15:09.2 |
HIP 3276 |
23.81 |
| 2026-05-25 12:00 |
00:41:31.25 |
+03:15:22.5 |
HIP 3276 |
23.48 |
| 2026-05-26 00:00 |
00:41:33.90 |
+03:15:35.5 |
HIP 3276 |
23.17 |
| 2026-05-26 12:00 |
00:41:36.51 |
+03:15:48.4 |
HIP 3276 |
22.88 |
| 2026-05-27 00:00 |
00:41:39.09 |
+03:16:01.0 |
HIP 3276 |
22.61 |
| 2026-05-27 12:00 |
00:41:41.65 |
+03:16:13.4 |
HIP 3276 |
22.37 |
| 2026-05-28 00:00 |
00:41:44.17 |
+03:16:25.6 |
HIP 3276 |
22.14 |
| 2026-05-28 12:00 |
00:41:46.65 |
+03:16:37.6 |
HIP 3276 |
21.94 |
| 2026-05-29 00:00 |
00:41:49.11 |
+03:16:49.4 |
HIP 3276 |
21.75 |
| 2026-05-29 12:00 |
00:41:51.53 |
+03:17:00.9 |
HIP 3276 |
21.59 |
| 2026-05-30 00:00 |
00:41:53.92 |
+03:17:12.3 |
HIP 3276 |
21.45 |
| 2026-05-30 12:00 |
00:41:56.28 |
+03:17:23.4 |
HIP 3276 |
21.32 |
| 2026-05-31 00:00 |
00:41:58.61 |
+03:17:34.3 |
HIP 3276 |
21.22 |
| 2026-05-31 12:00 |
00:42:00.90 |
+03:17:45.0 |
HIP 3276 |
21.14 |
| 2026-06-01 00:00 |
00:42:03.16 |
+03:17:55.4 |
HIP 3276 |
21.07 |
| 2026-06-01 12:00 |
00:42:05.38 |
+03:18:05.7 |
HIP 3276 |
21.03 |
| 2026-06-02 00:00 |
00:42:07.57 |
+03:18:15.7 |
HIP 3276 |
21.00 |