メタデータ
| 項目 |
値 |
| Designation |
C/1989 A1 (Yanaka) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1988-10-31T19:17:00.879360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:36Z |
| Obs used |
101 |
| NEO |
- |
| M1 |
5.700 |
| K1 |
16.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1989-02-04.0000000 |
| e |
0.99863759 |
| q (au) |
1.894621 |
| a (au) |
1390.639657 |
| i (deg) |
52.409723 |
| Ω (om, deg) |
157.088675 |
| ω (w, deg) |
351.561502 |
| M (ma, deg) |
0.001809 |
等級
散乱 + 全体線形
$$
M_a = (4.241 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
4.241 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| 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) |
| 2026-06-01 00:00 |
21:01:01.60 |
+06:21:54.2 |
HIP 103649 |
48.59 |
| 2026-06-01 12:00 |
21:01:00.80 |
+06:22:00.5 |
HIP 103649 |
48.63 |
| 2026-06-02 00:00 |
21:00:59.99 |
+06:22:06.6 |
HIP 103649 |
48.66 |
| 2026-06-02 12:00 |
21:00:59.16 |
+06:22:12.6 |
HIP 103649 |
48.70 |
| 2026-06-03 00:00 |
21:00:58.32 |
+06:22:18.6 |
HIP 103649 |
48.74 |
| 2026-06-03 12:00 |
21:00:57.47 |
+06:22:24.4 |
HIP 103649 |
48.77 |
| 2026-06-04 00:00 |
21:00:56.60 |
+06:22:30.2 |
HIP 103649 |
48.80 |
| 2026-06-04 12:00 |
21:00:55.72 |
+06:22:35.8 |
HIP 103649 |
48.83 |
| 2026-06-05 00:00 |
21:00:54.83 |
+06:22:41.3 |
HIP 103649 |
48.86 |
| 2026-06-05 12:00 |
21:00:53.92 |
+06:22:46.8 |
HIP 103649 |
48.89 |
| 2026-06-06 00:00 |
21:00:53.00 |
+06:22:52.1 |
HIP 103649 |
48.91 |
| 2026-06-06 12:00 |
21:00:52.07 |
+06:22:57.3 |
HIP 103649 |
48.94 |
| 2026-06-07 00:00 |
21:00:51.12 |
+06:23:02.4 |
HIP 103649 |
48.96 |
| 2026-06-07 12:00 |
21:00:50.16 |
+06:23:07.4 |
HIP 103649 |
48.98 |
| 2026-06-08 00:00 |
21:00:49.18 |
+06:23:12.3 |
HIP 103649 |
49.00 |
| 2026-06-08 12:00 |
21:00:48.19 |
+06:23:17.1 |
HIP 103649 |
49.02 |
| 2026-06-09 00:00 |
21:00:47.19 |
+06:23:21.8 |
HIP 103649 |
49.04 |
| 2026-06-09 12:00 |
21:00:46.18 |
+06:23:26.4 |
HIP 103649 |
49.06 |
| 2026-06-10 00:00 |
21:00:45.15 |
+06:23:30.9 |
HIP 103649 |
49.08 |
| 2026-06-10 12:00 |
21:00:44.11 |
+06:23:35.3 |
HIP 103649 |
49.09 |
| 2026-06-11 00:00 |
21:00:43.05 |
+06:23:39.5 |
HIP 103649 |
49.11 |
| 2026-06-11 12:00 |
21:00:41.99 |
+06:23:43.7 |
HIP 103649 |
49.12 |
| 2026-06-12 00:00 |
21:00:40.91 |
+06:23:47.7 |
HIP 103649 |
49.14 |
| 2026-06-12 12:00 |
21:00:39.82 |
+06:23:51.7 |
HIP 103490 |
49.13 |
| 2026-06-13 00:00 |
21:00:38.71 |
+06:23:55.5 |
HIP 103490 |
48.87 |
| 2026-06-13 12:00 |
21:00:37.59 |
+06:23:59.2 |
HIP 103490 |
48.61 |
| 2026-06-14 00:00 |
21:00:36.46 |
+06:24:02.8 |
HIP 103490 |
48.36 |
| 2026-06-14 12:00 |
21:00:35.32 |
+06:24:06.3 |
HIP 103490 |
48.10 |
| 2026-06-15 00:00 |
21:00:34.17 |
+06:24:09.7 |
HIP 103490 |
47.84 |
| 2026-06-15 12:00 |
21:00:33.00 |
+06:24:13.0 |
HIP 103490 |
47.58 |
| 2026-06-16 00:00 |
21:00:31.82 |
+06:24:16.1 |
HIP 103490 |
47.31 |
| 2026-06-16 12:00 |
21:00:30.63 |
+06:24:19.2 |
HIP 103490 |
47.05 |
| 2026-06-17 00:00 |
21:00:29.43 |
+06:24:22.1 |
HIP 103490 |
46.79 |
| 2026-06-17 12:00 |
21:00:28.22 |
+06:24:24.9 |
HIP 103490 |
46.52 |
| 2026-06-18 00:00 |
21:00:26.99 |
+06:24:27.6 |
HIP 103490 |
46.26 |
| 2026-06-18 12:00 |
21:00:25.75 |
+06:24:30.2 |
HIP 103490 |
46.00 |
| 2026-06-19 00:00 |
21:00:24.51 |
+06:24:32.7 |
HIP 103490 |
45.73 |
| 2026-06-19 12:00 |
21:00:23.25 |
+06:24:35.1 |
HIP 103490 |
45.47 |
| 2026-06-20 00:00 |
21:00:21.97 |
+06:24:37.3 |
HIP 103490 |
45.20 |
| 2026-06-20 12:00 |
21:00:20.69 |
+06:24:39.5 |
HIP 103490 |
44.93 |
| 2026-06-21 00:00 |
21:00:19.40 |
+06:24:41.5 |
HIP 103490 |
44.67 |
| 2026-06-21 12:00 |
21:00:18.09 |
+06:24:43.4 |
HIP 103490 |
44.40 |
| 2026-06-22 00:00 |
21:00:16.78 |
+06:24:45.2 |
HIP 103490 |
44.14 |