メタデータ
| 項目 |
値 |
| Designation |
C/1948 N1 (Wirtanen) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1949-05-01T03:57:14.875200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:09Z |
| Obs used |
20 |
| NEO |
- |
| M1 |
11.300 |
| K1 |
4.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1950-03-16.0000000 |
| e |
0.99945965 |
| q (au) |
2.517468 |
| a (au) |
4658.939225 |
| i (deg) |
130.267603 |
| Ω (om, deg) |
120.604872 |
| ω (w, deg) |
229.968351 |
| M (ma, deg) |
0.000988 |
等級
散乱 + 全体線形
$$
M_a = (7.043 + 4.134\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
7.043 |
| n |
4.134 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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 |
06:44:48.99 |
+46:38:40.9 |
HIP 32361 |
14.05 |
| 2026-05-12 12:00 |
06:44:50.07 |
+46:38:35.0 |
HIP 32361 |
14.08 |
| 2026-05-13 00:00 |
06:44:51.16 |
+46:38:29.2 |
HIP 32361 |
14.11 |
| 2026-05-13 12:00 |
06:44:52.26 |
+46:38:23.3 |
HIP 32361 |
14.15 |
| 2026-05-14 00:00 |
06:44:53.37 |
+46:38:17.5 |
HIP 32361 |
14.19 |
| 2026-05-14 12:00 |
06:44:54.49 |
+46:38:11.7 |
HIP 32361 |
14.22 |
| 2026-05-15 00:00 |
06:44:55.63 |
+46:38:06.0 |
HIP 32361 |
14.27 |
| 2026-05-15 12:00 |
06:44:56.77 |
+46:38:00.3 |
HIP 32361 |
14.31 |
| 2026-05-16 00:00 |
06:44:57.92 |
+46:37:54.6 |
HIP 32361 |
14.35 |
| 2026-05-16 12:00 |
06:44:59.09 |
+46:37:49.0 |
HIP 32361 |
14.40 |
| 2026-05-17 00:00 |
06:45:00.26 |
+46:37:43.4 |
HIP 32361 |
14.45 |
| 2026-05-17 12:00 |
06:45:01.44 |
+46:37:37.8 |
HIP 32361 |
14.50 |
| 2026-05-18 00:00 |
06:45:02.64 |
+46:37:32.3 |
HIP 32361 |
14.56 |
| 2026-05-18 12:00 |
06:45:03.84 |
+46:37:26.8 |
HIP 32361 |
14.61 |
| 2026-05-19 00:00 |
06:45:05.05 |
+46:37:21.3 |
HIP 32361 |
14.67 |
| 2026-05-19 12:00 |
06:45:06.28 |
+46:37:15.9 |
HIP 32361 |
14.73 |
| 2026-05-20 00:00 |
06:45:07.51 |
+46:37:10.5 |
HIP 32361 |
14.80 |
| 2026-05-20 12:00 |
06:45:08.75 |
+46:37:05.1 |
HIP 32361 |
14.86 |
| 2026-05-21 00:00 |
06:45:10.00 |
+46:36:59.8 |
HIP 32361 |
14.93 |
| 2026-05-21 12:00 |
06:45:11.26 |
+46:36:54.5 |
HIP 32361 |
15.00 |
| 2026-05-22 00:00 |
06:45:12.53 |
+46:36:49.3 |
HIP 32361 |
15.08 |
| 2026-05-22 12:00 |
06:45:13.81 |
+46:36:44.1 |
HIP 32361 |
15.15 |
| 2026-05-23 00:00 |
06:45:15.10 |
+46:36:39.0 |
HIP 32361 |
15.23 |
| 2026-05-23 12:00 |
06:45:16.39 |
+46:36:33.8 |
HIP 32361 |
15.32 |
| 2026-05-24 00:00 |
06:45:17.70 |
+46:36:28.8 |
HIP 32361 |
15.40 |
| 2026-05-24 12:00 |
06:45:19.01 |
+46:36:23.7 |
HIP 32361 |
15.49 |
| 2026-05-25 00:00 |
06:45:20.33 |
+46:36:18.7 |
HIP 32361 |
15.58 |
| 2026-05-25 12:00 |
06:45:21.66 |
+46:36:13.8 |
HIP 32361 |
15.67 |
| 2026-05-26 00:00 |
06:45:23.00 |
+46:36:08.9 |
HIP 32361 |
15.76 |
| 2026-05-26 12:00 |
06:45:24.35 |
+46:36:04.0 |
HIP 32361 |
15.86 |
| 2026-05-27 00:00 |
06:45:25.70 |
+46:35:59.2 |
HIP 32361 |
15.96 |
| 2026-05-27 12:00 |
06:45:27.07 |
+46:35:54.4 |
HIP 32361 |
16.06 |
| 2026-05-28 00:00 |
06:45:28.44 |
+46:35:49.7 |
HIP 32361 |
16.17 |
| 2026-05-28 12:00 |
06:45:29.82 |
+46:35:45.0 |
HIP 32361 |
16.28 |
| 2026-05-29 00:00 |
06:45:31.20 |
+46:35:40.3 |
HIP 32361 |
16.39 |
| 2026-05-29 12:00 |
06:45:32.60 |
+46:35:35.7 |
HIP 32361 |
16.50 |
| 2026-05-30 00:00 |
06:45:34.00 |
+46:35:31.1 |
HIP 32361 |
16.61 |
| 2026-05-30 12:00 |
06:45:35.41 |
+46:35:26.6 |
HIP 32361 |
16.73 |
| 2026-05-31 00:00 |
06:45:36.82 |
+46:35:22.1 |
HIP 32361 |
16.85 |
| 2026-05-31 12:00 |
06:45:38.25 |
+46:35:17.7 |
HIP 32361 |
16.97 |
| 2026-06-01 00:00 |
06:45:39.68 |
+46:35:13.3 |
HIP 32361 |
17.10 |
| 2026-06-01 12:00 |
06:45:41.11 |
+46:35:08.9 |
HIP 32361 |
17.23 |
| 2026-06-02 00:00 |
06:45:42.56 |
+46:35:04.6 |
HIP 32361 |
17.36 |