メタデータ
| 項目 |
値 |
| Designation |
417P/NEOWISE |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-04-21T21:50:27.404160Z |
| Orbit solution date (soln_date, UTC) |
2025-04-09T14:06:24Z |
| Obs used |
277 |
| NEO |
- |
| M1 |
17.500 |
| K1 |
6.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-01-17T05:24:50.284800Z |
| Discovery magnitude (MPC) |
20.40 T |
| Discovery observatory (MPC) |
Z84 · Calar Alto-Schmidt |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2019-01-27.0000000 |
| e |
0.55459375 |
| q (au) |
1.492286 |
| a (au) |
3.350393 |
| i (deg) |
8.129115 |
| Ω (om, deg) |
111.357188 |
| ω (w, deg) |
129.397423 |
| M (ma, deg) |
228.869825 |
等級
散乱 + 全体線形
$$
M_a = (17.824 + 3.206\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
17.824 |
| n |
3.206 |
| gf |
0.800 |
| gb |
-0.673 |
| k |
0.914 |
| δ90 |
1.000 |
| 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
ファインディングチャート
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
08:38:59.13 |
+22:59:41.7 |
HIP 42443 |
11.83 |
| 2026-07-29 12:00 |
08:39:46.58 |
+22:57:25.0 |
HIP 42443 |
11.65 |
| 2026-07-30 00:00 |
08:40:34.08 |
+22:55:07.6 |
HIP 42443 |
19.53 |
| 2026-07-30 12:00 |
08:41:21.62 |
+22:52:49.3 |
HIP 42443 |
29.62 |
| 2026-07-31 00:00 |
08:42:09.22 |
+22:50:30.2 |
HIP 42840 |
23.51 |
| 2026-07-31 12:00 |
08:42:56.85 |
+22:48:10.3 |
HIP 42840 |
12.45 |
| 2026-08-01 00:00 |
08:43:44.54 |
+22:45:49.6 |
HIP 42840 |
3.04 |
| 2026-08-01 12:00 |
08:44:32.27 |
+22:43:28.1 |
HIP 42840 |
10.79 |
| 2026-08-02 00:00 |
08:45:20.04 |
+22:41:05.7 |
HIP 42840 |
21.85 |
| 2026-08-02 12:00 |
08:46:07.87 |
+22:38:42.6 |
HIP 43078 |
18.24 |
| 2026-08-03 00:00 |
08:46:55.73 |
+22:36:18.6 |
HIP 43078 |
16.39 |
| 2026-08-03 12:00 |
08:47:43.64 |
+22:33:53.8 |
HIP 43078 |
21.47 |
| 2026-08-04 00:00 |
08:48:31.60 |
+22:31:28.2 |
HIP 43275 |
17.83 |
| 2026-08-04 12:00 |
08:49:19.60 |
+22:29:01.8 |
HIP 43275 |
15.09 |
| 2026-08-05 00:00 |
08:50:07.64 |
+22:26:34.5 |
HIP 43275 |
19.89 |
| 2026-08-05 12:00 |
08:50:55.73 |
+22:24:06.5 |
HIP 43595 |
26.86 |
| 2026-08-06 00:00 |
08:51:43.87 |
+22:21:37.6 |
HIP 43595 |
18.41 |
| 2026-08-06 12:00 |
08:52:32.04 |
+22:19:08.0 |
HIP 43595 |
14.69 |
| 2026-08-07 00:00 |
08:53:20.26 |
+22:16:37.5 |
HIP 43727 |
14.10 |
| 2026-08-07 12:00 |
08:54:08.52 |
+22:14:06.3 |
HIP 43727 |
2.75 |
| 2026-08-08 00:00 |
08:54:56.83 |
+22:11:34.2 |
HIP 43727 |
8.88 |
| 2026-08-08 12:00 |
08:55:45.18 |
+22:09:01.3 |
HIP 43727 |
20.34 |
| 2026-08-09 00:00 |
08:56:33.57 |
+22:06:27.6 |
HIP 43950 |
16.54 |
| 2026-08-09 12:00 |
08:57:22.00 |
+22:03:53.2 |
HIP 43950 |
12.87 |
| 2026-08-10 00:00 |
08:58:10.47 |
+22:01:17.9 |
HIP 43950 |
17.97 |
| 2026-08-10 12:00 |
08:58:58.98 |
+21:58:41.8 |
HIP 43950 |
27.33 |
| 2026-08-11 00:00 |
08:59:47.53 |
+21:56:05.0 |
HIP 44259 |
31.98 |
| 2026-08-11 12:00 |
09:00:36.12 |
+21:53:27.3 |
HIP 44259 |
26.31 |
| 2026-08-12 00:00 |
09:01:24.75 |
+21:50:48.9 |
HIP 44259 |
25.10 |
| 2026-08-12 12:00 |
09:02:13.42 |
+21:48:09.7 |
HIP 44408 |
18.54 |
| 2026-08-13 00:00 |
09:03:02.13 |
+21:45:29.7 |
HIP 44408 |
14.87 |
| 2026-08-13 12:00 |
09:03:50.87 |
+21:42:49.0 |
HIP 44408 |
19.22 |
| 2026-08-14 00:00 |
09:04:39.66 |
+21:40:07.4 |
HIP 44408 |
28.09 |
| 2026-08-14 12:00 |
09:05:28.48 |
+21:37:25.1 |
HIP 44812 |
34.62 |
| 2026-08-15 00:00 |
09:06:17.33 |
+21:34:42.0 |
HIP 44812 |
23.20 |
| 2026-08-15 12:00 |
09:07:06.23 |
+21:31:58.2 |
HIP 44812 |
12.27 |
| 2026-08-16 00:00 |
09:07:55.15 |
+21:29:13.6 |
HIP 44812 |
6.01 |
| 2026-08-16 12:00 |
09:08:44.12 |
+21:26:28.2 |
HIP 44812 |
14.00 |
| 2026-08-17 00:00 |
09:09:33.12 |
+21:23:42.1 |
HIP 45046 |
21.21 |
| 2026-08-17 12:00 |
09:10:22.15 |
+21:20:55.2 |
HIP 45046 |
19.45 |
| 2026-08-18 00:00 |
09:11:11.22 |
+21:18:07.6 |
HIP 45046 |
24.14 |
| 2026-08-18 12:00 |
09:12:00.32 |
+21:15:19.2 |
HIP 45272 |
22.65 |
| 2026-08-19 00:00 |
09:12:49.46 |
+21:12:30.0 |
HIP 45272 |
12.01 |