メタデータ
| 項目 |
値 |
| Designation |
C/2002 E2 (Snyder-Murakami) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2002-02-21T19:01:43.622400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:15Z |
| Obs used |
905 |
| NEO |
- |
| M1 |
10.600 |
| K1 |
7.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2002-05-22.0000000 |
| e |
1.00078903 |
| q (au) |
1.466445 |
| a (au) |
-1858.536843 |
| i (deg) |
92.544982 |
| Ω (om, deg) |
244.582842 |
| ω (w, deg) |
9.034141 |
| M (ma, deg) |
0.001097 |
等級
散乱 + 全体線形
$$
M_a = (8.648 + 4.589\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.648 |
| n |
4.589 |
| gf |
0.980 |
| gb |
-1.000 |
| k |
0.992 |
| δ90 |
9.688 |
| 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 |
04:01:35.03 |
+32:17:33.5 |
HIP 18780 |
2.54 |
| 2026-05-12 12:00 |
04:01:37.90 |
+32:17:37.6 |
HIP 18780 |
3.10 |
| 2026-05-13 00:00 |
04:01:40.77 |
+32:17:41.8 |
HIP 18780 |
3.67 |
| 2026-05-13 12:00 |
04:01:43.64 |
+32:17:46.1 |
HIP 18780 |
4.25 |
| 2026-05-14 00:00 |
04:01:46.52 |
+32:17:50.4 |
HIP 18780 |
4.84 |
| 2026-05-14 12:00 |
04:01:49.40 |
+32:17:54.8 |
HIP 18807 |
5.03 |
| 2026-05-15 00:00 |
04:01:52.29 |
+32:17:59.3 |
HIP 18807 |
5.22 |
| 2026-05-15 12:00 |
04:01:55.18 |
+32:18:03.8 |
HIP 18807 |
5.47 |
| 2026-05-16 00:00 |
04:01:58.07 |
+32:18:08.5 |
HIP 18807 |
5.78 |
| 2026-05-16 12:00 |
04:02:00.96 |
+32:18:13.1 |
HIP 18807 |
6.13 |
| 2026-05-17 00:00 |
04:02:03.86 |
+32:18:17.9 |
HIP 18807 |
6.53 |
| 2026-05-17 12:00 |
04:02:06.76 |
+32:18:22.7 |
HIP 18807 |
6.96 |
| 2026-05-18 00:00 |
04:02:09.66 |
+32:18:27.6 |
HIP 18807 |
7.41 |
| 2026-05-18 12:00 |
04:02:12.57 |
+32:18:32.5 |
HIP 18807 |
7.89 |
| 2026-05-19 00:00 |
04:02:15.48 |
+32:18:37.5 |
HIP 18807 |
8.39 |
| 2026-05-19 12:00 |
04:02:18.38 |
+32:18:42.6 |
HIP 18807 |
8.91 |
| 2026-05-20 00:00 |
04:02:21.30 |
+32:18:47.8 |
HIP 18807 |
9.44 |
| 2026-05-20 12:00 |
04:02:24.21 |
+32:18:53.0 |
HIP 18807 |
9.98 |
| 2026-05-21 00:00 |
04:02:27.12 |
+32:18:58.2 |
HIP 18807 |
10.53 |
| 2026-05-21 12:00 |
04:02:30.03 |
+32:19:03.6 |
HIP 18807 |
11.09 |
| 2026-05-22 00:00 |
04:02:32.95 |
+32:19:09.0 |
HIP 18807 |
11.65 |
| 2026-05-22 12:00 |
04:02:35.86 |
+32:19:14.4 |
HIP 18807 |
12.22 |
| 2026-05-23 00:00 |
04:02:38.78 |
+32:19:19.9 |
HIP 18807 |
12.80 |
| 2026-05-23 12:00 |
04:02:41.70 |
+32:19:25.5 |
HIP 18807 |
13.38 |
| 2026-05-24 00:00 |
04:02:44.61 |
+32:19:31.1 |
HIP 18807 |
13.97 |
| 2026-05-24 12:00 |
04:02:47.53 |
+32:19:36.8 |
HIP 18807 |
14.56 |
| 2026-05-25 00:00 |
04:02:50.44 |
+32:19:42.6 |
HIP 18807 |
15.15 |
| 2026-05-25 12:00 |
04:02:53.36 |
+32:19:48.4 |
HIP 18807 |
15.75 |
| 2026-05-26 00:00 |
04:02:56.27 |
+32:19:54.3 |
HIP 18807 |
16.34 |
| 2026-05-26 12:00 |
04:02:59.18 |
+32:20:00.2 |
HIP 18807 |
16.94 |
| 2026-05-27 00:00 |
04:03:02.10 |
+32:20:06.2 |
HIP 18807 |
17.54 |
| 2026-05-27 12:00 |
04:03:05.01 |
+32:20:12.2 |
HIP 18807 |
18.15 |
| 2026-05-28 00:00 |
04:03:07.92 |
+32:20:18.3 |
HIP 18807 |
18.75 |
| 2026-05-28 12:00 |
04:03:10.82 |
+32:20:24.5 |
HIP 18807 |
19.36 |
| 2026-05-29 00:00 |
04:03:13.73 |
+32:20:30.7 |
HIP 18807 |
19.96 |
| 2026-05-29 12:00 |
04:03:16.63 |
+32:20:36.9 |
HIP 18807 |
20.57 |
| 2026-05-30 00:00 |
04:03:19.53 |
+32:20:43.2 |
HIP 18807 |
21.18 |
| 2026-05-30 12:00 |
04:03:22.43 |
+32:20:49.6 |
HIP 19013 |
20.96 |
| 2026-05-31 00:00 |
04:03:25.33 |
+32:20:56.0 |
HIP 19013 |
20.51 |
| 2026-05-31 12:00 |
04:03:28.22 |
+32:21:02.5 |
HIP 19013 |
20.06 |
| 2026-06-01 00:00 |
04:03:31.11 |
+32:21:09.0 |
HIP 19013 |
19.62 |
| 2026-06-01 12:00 |
04:03:34.00 |
+32:21:15.6 |
HIP 19013 |
19.18 |
| 2026-06-02 00:00 |
04:03:36.88 |
+32:21:22.2 |
HIP 19013 |
18.76 |