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 |
-0.500 |
| 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) |
| 2026-03-26 00:00 |
21:00:31.00 |
+05:57:31.9 |
HIP 103649 |
23.06 |
| 2026-03-26 12:00 |
21:00:32.21 |
+05:57:44.9 |
HIP 103649 |
23.36 |
| 2026-03-27 00:00 |
21:00:33.40 |
+05:57:58.0 |
HIP 103649 |
23.66 |
| 2026-03-27 12:00 |
21:00:34.58 |
+05:58:11.0 |
HIP 103649 |
23.96 |
| 2026-03-28 00:00 |
21:00:35.74 |
+05:58:24.1 |
HIP 103649 |
24.26 |
| 2026-03-28 12:00 |
21:00:36.90 |
+05:58:37.2 |
HIP 103649 |
24.57 |
| 2026-03-29 00:00 |
21:00:38.04 |
+05:58:50.3 |
HIP 103649 |
24.87 |
| 2026-03-29 12:00 |
21:00:39.16 |
+05:59:03.3 |
HIP 103649 |
25.18 |
| 2026-03-30 00:00 |
21:00:40.28 |
+05:59:16.4 |
HIP 103649 |
25.48 |
| 2026-03-30 12:00 |
21:00:41.38 |
+05:59:29.5 |
HIP 103649 |
25.79 |
| 2026-03-31 00:00 |
21:00:42.47 |
+05:59:42.6 |
HIP 103649 |
26.09 |
| 2026-03-31 12:00 |
21:00:43.54 |
+05:59:55.7 |
HIP 103649 |
26.39 |
| 2026-04-01 00:00 |
21:00:44.60 |
+06:00:08.7 |
HIP 103649 |
26.70 |
| 2026-04-01 12:00 |
21:00:45.65 |
+06:00:21.8 |
HIP 103649 |
27.00 |
| 2026-04-02 00:00 |
21:00:46.68 |
+06:00:34.9 |
HIP 103649 |
27.30 |
| 2026-04-02 12:00 |
21:00:47.70 |
+06:00:48.0 |
HIP 103649 |
27.61 |
| 2026-04-03 00:00 |
21:00:48.71 |
+06:01:01.0 |
HIP 103649 |
27.91 |
| 2026-04-03 12:00 |
21:00:49.70 |
+06:01:14.1 |
HIP 103649 |
28.21 |
| 2026-04-04 00:00 |
21:00:50.68 |
+06:01:27.2 |
HIP 103649 |
28.51 |
| 2026-04-04 12:00 |
21:00:51.65 |
+06:01:40.2 |
HIP 103649 |
28.81 |
| 2026-04-05 00:00 |
21:00:52.60 |
+06:01:53.2 |
HIP 103649 |
29.10 |
| 2026-04-05 12:00 |
21:00:53.54 |
+06:02:06.3 |
HIP 103649 |
29.40 |
| 2026-04-06 00:00 |
21:00:54.46 |
+06:02:19.3 |
HIP 103649 |
29.70 |
| 2026-04-06 12:00 |
21:00:55.37 |
+06:02:32.3 |
HIP 103649 |
29.99 |
| 2026-04-07 00:00 |
21:00:56.27 |
+06:02:45.3 |
HIP 103649 |
30.28 |
| 2026-04-07 12:00 |
21:00:57.15 |
+06:02:58.3 |
HIP 103649 |
30.57 |
| 2026-04-08 00:00 |
21:00:58.02 |
+06:03:11.3 |
HIP 103649 |
30.86 |
| 2026-04-08 12:00 |
21:00:58.87 |
+06:03:24.2 |
HIP 103649 |
31.15 |
| 2026-04-09 00:00 |
21:00:59.71 |
+06:03:37.2 |
HIP 103649 |
31.44 |
| 2026-04-09 12:00 |
21:01:00.54 |
+06:03:50.1 |
HIP 103649 |
31.72 |
| 2026-04-10 00:00 |
21:01:01.35 |
+06:04:03.0 |
HIP 103649 |
32.01 |
| 2026-04-10 12:00 |
21:01:02.14 |
+06:04:15.9 |
HIP 103649 |
32.29 |
| 2026-04-11 00:00 |
21:01:02.92 |
+06:04:28.7 |
HIP 103649 |
32.57 |
| 2026-04-11 12:00 |
21:01:03.69 |
+06:04:41.6 |
HIP 103649 |
32.85 |
| 2026-04-12 00:00 |
21:01:04.44 |
+06:04:54.4 |
HIP 103649 |
33.12 |
| 2026-04-12 12:00 |
21:01:05.18 |
+06:05:07.2 |
HIP 103649 |
33.40 |
| 2026-04-13 00:00 |
21:01:05.90 |
+06:05:20.0 |
HIP 103649 |
33.67 |
| 2026-04-13 12:00 |
21:01:06.61 |
+06:05:32.8 |
HIP 103649 |
33.94 |
| 2026-04-14 00:00 |
21:01:07.30 |
+06:05:45.5 |
HIP 103649 |
34.21 |
| 2026-04-14 12:00 |
21:01:07.98 |
+06:05:58.2 |
HIP 103649 |
34.48 |
| 2026-04-15 00:00 |
21:01:08.64 |
+06:06:10.9 |
HIP 103649 |
34.74 |
| 2026-04-15 12:00 |
21:01:09.29 |
+06:06:23.5 |
HIP 103649 |
35.00 |
| 2026-04-16 00:00 |
21:01:09.92 |
+06:06:36.1 |
HIP 103649 |
35.26 |