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) |
| 2026-07-29 00:00 |
06:48:45.13 |
+46:32:43.3 |
HIP 32774 |
25.28 |
| 2026-07-29 12:00 |
06:48:46.64 |
+46:32:45.4 |
HIP 32774 |
25.18 |
| 2026-07-30 00:00 |
06:48:48.14 |
+46:32:47.5 |
HIP 32774 |
25.08 |
| 2026-07-30 12:00 |
06:48:49.63 |
+46:32:49.6 |
HIP 32774 |
24.98 |
| 2026-07-31 00:00 |
06:48:51.12 |
+46:32:51.9 |
HIP 32774 |
24.89 |
| 2026-07-31 12:00 |
06:48:52.61 |
+46:32:54.1 |
HIP 32774 |
24.80 |
| 2026-08-01 00:00 |
06:48:54.08 |
+46:32:56.5 |
HIP 32774 |
24.71 |
| 2026-08-01 12:00 |
06:48:55.56 |
+46:32:58.9 |
HIP 32774 |
24.63 |
| 2026-08-02 00:00 |
06:48:57.02 |
+46:33:01.3 |
HIP 32774 |
24.55 |
| 2026-08-02 12:00 |
06:48:58.48 |
+46:33:03.8 |
HIP 32774 |
24.48 |
| 2026-08-03 00:00 |
06:48:59.93 |
+46:33:06.4 |
HIP 32774 |
24.41 |
| 2026-08-03 12:00 |
06:49:01.37 |
+46:33:09.0 |
HIP 32774 |
24.34 |
| 2026-08-04 00:00 |
06:49:02.81 |
+46:33:11.7 |
HIP 32774 |
24.28 |
| 2026-08-04 12:00 |
06:49:04.24 |
+46:33:14.4 |
HIP 32774 |
24.22 |
| 2026-08-05 00:00 |
06:49:05.66 |
+46:33:17.2 |
HIP 32774 |
24.16 |
| 2026-08-05 12:00 |
06:49:07.08 |
+46:33:20.1 |
HIP 32774 |
24.11 |
| 2026-08-06 00:00 |
06:49:08.49 |
+46:33:23.0 |
HIP 32774 |
24.06 |
| 2026-08-06 12:00 |
06:49:09.89 |
+46:33:25.9 |
HIP 32774 |
24.02 |
| 2026-08-07 00:00 |
06:49:11.29 |
+46:33:29.0 |
HIP 32774 |
23.98 |
| 2026-08-07 12:00 |
06:49:12.67 |
+46:33:32.0 |
HIP 32774 |
23.94 |
| 2026-08-08 00:00 |
06:49:14.05 |
+46:33:35.2 |
HIP 32774 |
23.91 |
| 2026-08-08 12:00 |
06:49:15.42 |
+46:33:38.3 |
HIP 32774 |
23.88 |
| 2026-08-09 00:00 |
06:49:16.78 |
+46:33:41.6 |
HIP 32774 |
23.86 |
| 2026-08-09 12:00 |
06:49:18.14 |
+46:33:44.9 |
HIP 32774 |
23.83 |
| 2026-08-10 00:00 |
06:49:19.49 |
+46:33:48.2 |
HIP 32774 |
23.82 |
| 2026-08-10 12:00 |
06:49:20.82 |
+46:33:51.6 |
HIP 32774 |
23.80 |
| 2026-08-11 00:00 |
06:49:22.16 |
+46:33:55.1 |
HIP 32774 |
23.79 |
| 2026-08-11 12:00 |
06:49:23.48 |
+46:33:58.6 |
HIP 32774 |
23.79 |
| 2026-08-12 00:00 |
06:49:24.79 |
+46:34:02.1 |
HIP 32774 |
23.78 |
| 2026-08-12 12:00 |
06:49:26.09 |
+46:34:05.8 |
HIP 32774 |
23.78 |
| 2026-08-13 00:00 |
06:49:27.39 |
+46:34:09.4 |
HIP 32774 |
23.79 |
| 2026-08-13 12:00 |
06:49:28.68 |
+46:34:13.2 |
HIP 32774 |
23.79 |
| 2026-08-14 00:00 |
06:49:29.96 |
+46:34:16.9 |
HIP 32774 |
23.80 |
| 2026-08-14 12:00 |
06:49:31.22 |
+46:34:20.8 |
HIP 32774 |
23.82 |
| 2026-08-15 00:00 |
06:49:32.48 |
+46:34:24.7 |
HIP 32949 |
23.69 |
| 2026-08-15 12:00 |
06:49:33.73 |
+46:34:28.6 |
HIP 32949 |
23.49 |
| 2026-08-16 00:00 |
06:49:34.98 |
+46:34:32.6 |
HIP 32949 |
23.29 |
| 2026-08-16 12:00 |
06:49:36.21 |
+46:34:36.6 |
HIP 32949 |
23.10 |
| 2026-08-17 00:00 |
06:49:37.43 |
+46:34:40.7 |
HIP 32949 |
22.91 |
| 2026-08-17 12:00 |
06:49:38.64 |
+46:34:44.9 |
HIP 32949 |
22.72 |
| 2026-08-18 00:00 |
06:49:39.84 |
+46:34:49.1 |
HIP 32949 |
22.53 |
| 2026-08-18 12:00 |
06:49:41.04 |
+46:34:53.3 |
HIP 32949 |
22.34 |
| 2026-08-19 00:00 |
06:49:42.22 |
+46:34:57.6 |
HIP 32949 |
22.16 |