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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
00:42:09.73 |
+03:18:25.5 |
HIP 3276 |
20.98 |
| 2026-06-03 00:00 |
00:42:11.86 |
+03:18:35.0 |
HIP 3276 |
20.99 |
| 2026-06-03 12:00 |
00:42:13.95 |
+03:18:44.4 |
HIP 3276 |
21.01 |
| 2026-06-04 00:00 |
00:42:16.00 |
+03:18:53.5 |
HIP 3276 |
21.04 |
| 2026-06-04 12:00 |
00:42:18.02 |
+03:19:02.4 |
HIP 3276 |
21.09 |
| 2026-06-05 00:00 |
00:42:20.01 |
+03:19:11.0 |
HIP 3276 |
21.15 |
| 2026-06-05 12:00 |
00:42:21.96 |
+03:19:19.4 |
HIP 3276 |
21.22 |
| 2026-06-06 00:00 |
00:42:23.88 |
+03:19:27.6 |
HIP 3276 |
21.30 |
| 2026-06-06 12:00 |
00:42:25.76 |
+03:19:35.6 |
HIP 3276 |
21.40 |
| 2026-06-07 00:00 |
00:42:27.60 |
+03:19:43.3 |
HIP 3276 |
21.50 |
| 2026-06-07 12:00 |
00:42:29.41 |
+03:19:50.8 |
HIP 3276 |
21.61 |
| 2026-06-08 00:00 |
00:42:31.19 |
+03:19:58.1 |
HIP 3276 |
21.73 |
| 2026-06-08 12:00 |
00:42:32.93 |
+03:20:05.1 |
HIP 3276 |
21.86 |
| 2026-06-09 00:00 |
00:42:34.63 |
+03:20:11.9 |
HIP 3276 |
22.00 |
| 2026-06-09 12:00 |
00:42:36.30 |
+03:20:18.4 |
HIP 3276 |
22.14 |
| 2026-06-10 00:00 |
00:42:37.93 |
+03:20:24.7 |
HIP 3276 |
22.29 |
| 2026-06-10 12:00 |
00:42:39.52 |
+03:20:30.8 |
HIP 3276 |
22.44 |
| 2026-06-11 00:00 |
00:42:41.07 |
+03:20:36.6 |
HIP 3276 |
22.60 |
| 2026-06-11 12:00 |
00:42:42.59 |
+03:20:42.2 |
HIP 3276 |
22.75 |
| 2026-06-12 00:00 |
00:42:44.08 |
+03:20:47.5 |
HIP 3276 |
22.92 |
| 2026-06-12 12:00 |
00:42:45.52 |
+03:20:52.6 |
HIP 3276 |
23.08 |
| 2026-06-13 00:00 |
00:42:46.93 |
+03:20:57.4 |
HIP 3276 |
23.25 |
| 2026-06-13 12:00 |
00:42:48.30 |
+03:21:02.0 |
HIP 3276 |
23.41 |
| 2026-06-14 00:00 |
00:42:49.63 |
+03:21:06.3 |
HIP 3276 |
23.58 |
| 2026-06-14 12:00 |
00:42:50.92 |
+03:21:10.4 |
HIP 3276 |
23.75 |
| 2026-06-15 00:00 |
00:42:52.18 |
+03:21:14.3 |
HIP 3276 |
23.92 |
| 2026-06-15 12:00 |
00:42:53.39 |
+03:21:17.9 |
HIP 3276 |
24.09 |
| 2026-06-16 00:00 |
00:42:54.57 |
+03:21:21.2 |
HIP 3276 |
24.25 |
| 2026-06-16 12:00 |
00:42:55.71 |
+03:21:24.3 |
HIP 3276 |
24.42 |
| 2026-06-17 00:00 |
00:42:56.81 |
+03:21:27.1 |
HIP 3276 |
24.58 |
| 2026-06-17 12:00 |
00:42:57.88 |
+03:21:29.7 |
HIP 3276 |
24.74 |
| 2026-06-18 00:00 |
00:42:58.90 |
+03:21:32.0 |
HIP 3276 |
24.90 |
| 2026-06-18 12:00 |
00:42:59.88 |
+03:21:34.1 |
HIP 3276 |
25.06 |
| 2026-06-19 00:00 |
00:43:00.83 |
+03:21:35.9 |
HIP 3276 |
25.21 |
| 2026-06-19 12:00 |
00:43:01.74 |
+03:21:37.5 |
HIP 3276 |
25.36 |
| 2026-06-20 00:00 |
00:43:02.60 |
+03:21:38.8 |
HIP 3276 |
25.51 |
| 2026-06-20 12:00 |
00:43:03.43 |
+03:21:39.8 |
HIP 3276 |
25.65 |
| 2026-06-21 00:00 |
00:43:04.22 |
+03:21:40.6 |
HIP 3276 |
25.79 |
| 2026-06-21 12:00 |
00:43:04.96 |
+03:21:41.1 |
HIP 3276 |
25.93 |
| 2026-06-22 00:00 |
00:43:05.67 |
+03:21:41.4 |
HIP 3276 |
26.06 |