メタデータ
| 項目 |
値 |
| Designation |
254P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2020-09-29T14:29:03.868800Z |
| Orbit solution date (soln_date, UTC) |
2026-03-07T14:43:32Z |
| Obs used |
834 |
| NEO |
- |
| M1 |
12.900 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2020-08-07.0000000 |
| e |
0.32026893 |
| q (au) |
3.136948 |
| a (au) |
4.614984 |
| i (deg) |
32.571408 |
| Ω (om, deg) |
129.173330 |
| ω (w, deg) |
219.469297 |
| M (ma, deg) |
354.671045 |
等級
散乱 + 全体線形
$$
M_a = (5.492 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
5.492 |
| n |
6.000 |
| gf |
0.899 |
| gb |
-0.531 |
| k |
0.991 |
| δ90 |
3.786 |
| 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) |
| 2026-06-01 00:00 |
12:00:25.68 |
+29:15:54.7 |
HIP 58577 |
6.75 |
| 2026-06-01 12:00 |
12:00:26.08 |
+29:14:12.2 |
HIP 58577 |
5.63 |
| 2026-06-02 00:00 |
12:00:26.65 |
+29:12:28.8 |
HIP 58577 |
4.82 |
| 2026-06-02 12:00 |
12:00:27.38 |
+29:10:44.4 |
HIP 58577 |
4.52 |
| 2026-06-03 00:00 |
12:00:28.28 |
+29:08:59.0 |
HIP 58577 |
4.86 |
| 2026-06-03 12:00 |
12:00:29.34 |
+29:07:12.6 |
HIP 58577 |
5.72 |
| 2026-06-04 00:00 |
12:00:30.57 |
+29:05:25.3 |
HIP 58577 |
6.95 |
| 2026-06-04 12:00 |
12:00:31.96 |
+29:03:37.0 |
HIP 58577 |
8.38 |
| 2026-06-05 00:00 |
12:00:33.52 |
+29:01:47.7 |
HIP 58577 |
9.95 |
| 2026-06-05 12:00 |
12:00:35.24 |
+28:59:57.6 |
HIP 58577 |
11.61 |
| 2026-06-06 00:00 |
12:00:37.12 |
+28:58:06.5 |
HIP 58577 |
13.34 |
| 2026-06-06 12:00 |
12:00:39.17 |
+28:56:14.6 |
HIP 58577 |
15.12 |
| 2026-06-07 00:00 |
12:00:41.38 |
+28:54:21.7 |
HIP 58577 |
16.94 |
| 2026-06-07 12:00 |
12:00:43.75 |
+28:52:27.9 |
HIP 58577 |
18.79 |
| 2026-06-08 00:00 |
12:00:46.29 |
+28:50:33.3 |
HIP 58500 |
20.53 |
| 2026-06-08 12:00 |
12:00:48.98 |
+28:48:37.8 |
HIP 58500 |
19.42 |
| 2026-06-09 00:00 |
12:00:51.84 |
+28:46:41.4 |
HIP 58500 |
18.47 |
| 2026-06-09 12:00 |
12:00:54.86 |
+28:44:44.2 |
HIP 58500 |
17.73 |
| 2026-06-10 00:00 |
12:00:58.04 |
+28:42:46.2 |
HIP 58500 |
17.23 |
| 2026-06-10 12:00 |
12:01:01.38 |
+28:40:47.3 |
HIP 58500 |
17.00 |
| 2026-06-11 00:00 |
12:01:04.87 |
+28:38:47.6 |
HIP 58500 |
17.06 |
| 2026-06-11 12:00 |
12:01:08.53 |
+28:36:47.1 |
HIP 58500 |
17.42 |
| 2026-06-12 00:00 |
12:01:12.35 |
+28:34:45.8 |
HIP 58500 |
18.07 |
| 2026-06-12 12:00 |
12:01:16.33 |
+28:32:43.7 |
HIP 58500 |
18.98 |
| 2026-06-13 00:00 |
12:01:20.47 |
+28:30:40.9 |
HIP 58500 |
20.14 |
| 2026-06-13 12:00 |
12:01:24.76 |
+28:28:37.2 |
HIP 58500 |
21.51 |
| 2026-06-14 00:00 |
12:01:29.22 |
+28:26:32.8 |
HIP 58500 |
23.05 |
| 2026-06-14 12:00 |
12:01:33.83 |
+28:24:27.7 |
HIP 58500 |
24.75 |
| 2026-06-15 00:00 |
12:01:38.59 |
+28:22:21.8 |
HIP 58606 |
25.71 |
| 2026-06-15 12:00 |
12:01:43.51 |
+28:20:15.2 |
HIP 58606 |
24.06 |
| 2026-06-16 00:00 |
12:01:48.59 |
+28:18:07.9 |
HIP 58606 |
22.54 |
| 2026-06-16 12:00 |
12:01:53.83 |
+28:16:00.0 |
HIP 58606 |
21.19 |
| 2026-06-17 00:00 |
12:01:59.22 |
+28:13:51.2 |
HIP 58606 |
20.05 |
| 2026-06-17 12:00 |
12:02:04.76 |
+28:11:41.8 |
HIP 58606 |
19.18 |
| 2026-06-18 00:00 |
12:02:10.46 |
+28:09:31.8 |
HIP 58606 |
18.62 |
| 2026-06-18 12:00 |
12:02:16.30 |
+28:07:21.0 |
HIP 58606 |
18.41 |
| 2026-06-19 00:00 |
12:02:22.31 |
+28:05:09.7 |
HIP 58606 |
18.57 |
| 2026-06-19 12:00 |
12:02:28.46 |
+28:02:57.7 |
HIP 58606 |
19.11 |
| 2026-06-20 00:00 |
12:02:34.76 |
+28:00:45.1 |
HIP 58606 |
20.01 |
| 2026-06-20 12:00 |
12:02:41.21 |
+27:58:31.8 |
HIP 58838 |
19.21 |
| 2026-06-21 00:00 |
12:02:47.81 |
+27:56:18.0 |
HIP 58838 |
18.57 |
| 2026-06-21 12:00 |
12:02:54.56 |
+27:54:03.5 |
HIP 58838 |
18.28 |
| 2026-06-22 00:00 |
12:03:01.46 |
+27:51:48.5 |
HIP 58838 |
18.37 |