メタデータ
| 項目 |
値 |
| Designation |
C/1919 Q2 (Metcalf) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1919-12-07T19:37:10.358400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:02Z |
| Obs used |
18 |
| NEO |
- |
| M1 |
5.100 |
| K1 |
11.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1919-09-18.0000000 |
| e |
0.99977859 |
| q (au) |
1.115204 |
| a (au) |
5036.797426 |
| i (deg) |
46.383158 |
| Ω (om, deg) |
122.097279 |
| ω (w, deg) |
185.764445 |
| M (ma, deg) |
359.999777 |
等級
散乱 + 全体線形
$$
M_a = (6.671 + 5.125\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
6.671 |
| n |
5.125 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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) |
| 2026-09-20 00:00 |
08:01:35.67 |
+16:51:56.5 |
HIP 39226 |
5.85 |
| 2026-09-20 12:00 |
08:01:36.16 |
+16:51:54.4 |
HIP 39226 |
5.94 |
| 2026-09-21 00:00 |
08:01:36.65 |
+16:51:52.3 |
HIP 39226 |
6.04 |
| 2026-09-21 12:00 |
08:01:37.13 |
+16:51:50.2 |
HIP 39226 |
6.13 |
| 2026-09-22 00:00 |
08:01:37.61 |
+16:51:48.2 |
HIP 39226 |
6.22 |
| 2026-09-22 12:00 |
08:01:38.08 |
+16:51:46.2 |
HIP 39226 |
6.31 |
| 2026-09-23 00:00 |
08:01:38.54 |
+16:51:44.1 |
HIP 39226 |
6.40 |
| 2026-09-23 12:00 |
08:01:38.99 |
+16:51:42.1 |
HIP 39226 |
6.49 |
| 2026-09-24 00:00 |
08:01:39.44 |
+16:51:40.1 |
HIP 39226 |
6.58 |
| 2026-09-24 12:00 |
08:01:39.87 |
+16:51:38.2 |
HIP 39226 |
6.67 |
| 2026-09-25 00:00 |
08:01:40.31 |
+16:51:36.2 |
HIP 39226 |
6.76 |
| 2026-09-25 12:00 |
08:01:40.73 |
+16:51:34.3 |
HIP 39226 |
6.84 |
| 2026-09-26 00:00 |
08:01:41.15 |
+16:51:32.4 |
HIP 39226 |
6.93 |
| 2026-09-26 12:00 |
08:01:41.56 |
+16:51:30.5 |
HIP 39226 |
7.02 |
| 2026-09-27 00:00 |
08:01:41.96 |
+16:51:28.6 |
HIP 39226 |
7.10 |
| 2026-09-27 12:00 |
08:01:42.35 |
+16:51:26.8 |
HIP 39228 |
7.18 |
| 2026-09-28 00:00 |
08:01:42.74 |
+16:51:24.9 |
HIP 39228 |
7.27 |
| 2026-09-28 12:00 |
08:01:43.12 |
+16:51:23.1 |
HIP 39228 |
7.35 |
| 2026-09-29 00:00 |
08:01:43.49 |
+16:51:21.3 |
HIP 39228 |
7.43 |
| 2026-09-29 12:00 |
08:01:43.85 |
+16:51:19.5 |
HIP 39228 |
7.50 |
| 2026-09-30 00:00 |
08:01:44.21 |
+16:51:17.8 |
HIP 39228 |
7.58 |
| 2026-09-30 12:00 |
08:01:44.56 |
+16:51:16.0 |
HIP 39228 |
7.66 |
| 2026-10-01 00:00 |
08:01:44.90 |
+16:51:14.3 |
HIP 39228 |
7.73 |
| 2026-10-01 12:00 |
08:01:45.24 |
+16:51:12.6 |
HIP 39228 |
7.81 |
| 2026-10-02 00:00 |
08:01:45.56 |
+16:51:10.9 |
HIP 39228 |
7.88 |
| 2026-10-02 12:00 |
08:01:45.88 |
+16:51:09.2 |
HIP 39228 |
7.95 |
| 2026-10-03 00:00 |
08:01:46.19 |
+16:51:07.6 |
HIP 39228 |
8.02 |
| 2026-10-03 12:00 |
08:01:46.50 |
+16:51:06.0 |
HIP 39228 |
8.09 |
| 2026-10-04 00:00 |
08:01:46.79 |
+16:51:04.4 |
HIP 39228 |
8.16 |
| 2026-10-04 12:00 |
08:01:47.08 |
+16:51:02.8 |
HIP 39228 |
8.22 |
| 2026-10-05 00:00 |
08:01:47.36 |
+16:51:01.2 |
HIP 39228 |
8.29 |
| 2026-10-05 12:00 |
08:01:47.63 |
+16:50:59.7 |
HIP 39228 |
8.35 |
| 2026-10-06 00:00 |
08:01:47.89 |
+16:50:58.2 |
HIP 39228 |
8.41 |
| 2026-10-06 12:00 |
08:01:48.15 |
+16:50:56.7 |
HIP 39228 |
8.47 |
| 2026-10-07 00:00 |
08:01:48.40 |
+16:50:55.2 |
HIP 39228 |
8.53 |
| 2026-10-07 12:00 |
08:01:48.64 |
+16:50:53.7 |
HIP 39228 |
8.59 |
| 2026-10-08 00:00 |
08:01:48.87 |
+16:50:52.3 |
HIP 39228 |
8.65 |
| 2026-10-08 12:00 |
08:01:49.09 |
+16:50:50.9 |
HIP 39228 |
8.70 |
| 2026-10-09 00:00 |
08:01:49.31 |
+16:50:49.5 |
HIP 39228 |
8.75 |
| 2026-10-09 12:00 |
08:01:49.51 |
+16:50:48.1 |
HIP 39228 |
8.80 |
| 2026-10-10 00:00 |
08:01:49.71 |
+16:50:46.8 |
HIP 39228 |
8.85 |
| 2026-10-10 12:00 |
08:01:49.90 |
+16:50:45.4 |
HIP 39228 |
8.90 |
| 2026-10-11 00:00 |
08:01:50.09 |
+16:50:44.1 |
HIP 39228 |
8.95 |