メタデータ
| 項目 |
値 |
| Designation |
C/1947 O1 (Wirtanen) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1947-07-16T20:09:37.615680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:07Z |
| Obs used |
3 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1948-03-29.0000000 |
| e |
1.01675158 |
| q (au) |
2.807881 |
| a (au) |
-167.618847 |
| i (deg) |
97.324802 |
| Ω (om, deg) |
311.764379 |
| ω (w, deg) |
8.848565 |
| M (ma, deg) |
0.116341 |
等級
散乱 + 全体線形
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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) |
| 2026-09-20 00:00 |
09:20:53.96 |
+28:21:43.4 |
HIP 45767 |
13.02 |
| 2026-09-20 12:00 |
09:20:54.85 |
+28:21:41.7 |
HIP 45767 |
13.20 |
| 2026-09-21 00:00 |
09:20:55.74 |
+28:21:40.1 |
HIP 45913 |
13.36 |
| 2026-09-21 12:00 |
09:20:56.61 |
+28:21:38.5 |
HIP 45913 |
13.22 |
| 2026-09-22 00:00 |
09:20:57.49 |
+28:21:36.9 |
HIP 45913 |
13.09 |
| 2026-09-22 12:00 |
09:20:58.35 |
+28:21:35.4 |
HIP 45913 |
12.96 |
| 2026-09-23 00:00 |
09:20:59.21 |
+28:21:33.9 |
HIP 45913 |
12.84 |
| 2026-09-23 12:00 |
09:21:00.06 |
+28:21:32.5 |
HIP 45913 |
12.71 |
| 2026-09-24 00:00 |
09:21:00.91 |
+28:21:31.2 |
HIP 45913 |
12.59 |
| 2026-09-24 12:00 |
09:21:01.74 |
+28:21:29.9 |
HIP 45913 |
12.47 |
| 2026-09-25 00:00 |
09:21:02.57 |
+28:21:28.6 |
HIP 45913 |
12.35 |
| 2026-09-25 12:00 |
09:21:03.40 |
+28:21:27.4 |
HIP 45913 |
12.23 |
| 2026-09-26 00:00 |
09:21:04.22 |
+28:21:26.3 |
HIP 45913 |
12.12 |
| 2026-09-26 12:00 |
09:21:05.03 |
+28:21:25.2 |
HIP 45913 |
12.01 |
| 2026-09-27 00:00 |
09:21:05.83 |
+28:21:24.1 |
HIP 45913 |
11.90 |
| 2026-09-27 12:00 |
09:21:06.63 |
+28:21:23.1 |
HIP 45913 |
11.79 |
| 2026-09-28 00:00 |
09:21:07.41 |
+28:21:22.2 |
HIP 45913 |
11.68 |
| 2026-09-28 12:00 |
09:21:08.20 |
+28:21:21.3 |
HIP 45913 |
11.58 |
| 2026-09-29 00:00 |
09:21:08.97 |
+28:21:20.4 |
HIP 45913 |
11.48 |
| 2026-09-29 12:00 |
09:21:09.74 |
+28:21:19.7 |
HIP 45913 |
11.38 |
| 2026-09-30 00:00 |
09:21:10.50 |
+28:21:18.9 |
HIP 45913 |
11.28 |
| 2026-09-30 12:00 |
09:21:11.25 |
+28:21:18.2 |
HIP 45913 |
11.18 |
| 2026-10-01 00:00 |
09:21:11.99 |
+28:21:17.6 |
HIP 45913 |
11.09 |
| 2026-10-01 12:00 |
09:21:12.73 |
+28:21:17.0 |
HIP 45913 |
11.00 |
| 2026-10-02 00:00 |
09:21:13.46 |
+28:21:16.5 |
HIP 45913 |
10.91 |
| 2026-10-02 12:00 |
09:21:14.18 |
+28:21:16.0 |
HIP 45913 |
10.82 |
| 2026-10-03 00:00 |
09:21:14.89 |
+28:21:15.6 |
HIP 45913 |
10.74 |
| 2026-10-03 12:00 |
09:21:15.60 |
+28:21:15.2 |
HIP 45913 |
10.65 |
| 2026-10-04 00:00 |
09:21:16.30 |
+28:21:14.9 |
HIP 45913 |
10.57 |
| 2026-10-04 12:00 |
09:21:16.99 |
+28:21:14.6 |
HIP 45913 |
10.49 |
| 2026-10-05 00:00 |
09:21:17.67 |
+28:21:14.4 |
HIP 45913 |
10.41 |
| 2026-10-05 12:00 |
09:21:18.34 |
+28:21:14.2 |
HIP 45913 |
10.33 |
| 2026-10-06 00:00 |
09:21:19.01 |
+28:21:14.1 |
HIP 45913 |
10.26 |
| 2026-10-06 12:00 |
09:21:19.66 |
+28:21:14.0 |
HIP 45913 |
10.19 |
| 2026-10-07 00:00 |
09:21:20.31 |
+28:21:14.0 |
HIP 45913 |
10.12 |
| 2026-10-07 12:00 |
09:21:20.95 |
+28:21:14.1 |
HIP 45913 |
10.05 |
| 2026-10-08 00:00 |
09:21:21.58 |
+28:21:14.2 |
HIP 45913 |
9.98 |
| 2026-10-08 12:00 |
09:21:22.21 |
+28:21:14.3 |
HIP 45913 |
9.91 |
| 2026-10-09 00:00 |
09:21:22.82 |
+28:21:14.5 |
HIP 45913 |
9.85 |
| 2026-10-09 12:00 |
09:21:23.43 |
+28:21:14.8 |
HIP 45913 |
9.78 |
| 2026-10-10 00:00 |
09:21:24.03 |
+28:21:15.1 |
HIP 45913 |
9.72 |
| 2026-10-10 12:00 |
09:21:24.61 |
+28:21:15.5 |
HIP 45913 |
9.66 |
| 2026-10-11 00:00 |
09:21:25.19 |
+28:21:15.9 |
HIP 45913 |
9.60 |