メタデータ
| 項目 |
値 |
| Designation |
C/1988 Y1 (Yanaka) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1988-12-11T15:40:33.395520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:36Z |
| Obs used |
56 |
| NEO |
- |
| M1 |
12.800 |
| K1 |
15.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1989-01-12.0000000 |
| e |
1.00000000 |
| q (au) |
0.427814 |
| a (au) |
- |
| i (deg) |
71.010955 |
| Ω (om, deg) |
315.523025 |
| ω (w, deg) |
88.122151 |
| M (ma, deg) |
- |
等級
散乱 + 全体線形
$$
M_a = (13.086 + 5.655\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.086 |
| n |
5.655 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
1.000 |
| 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) |
| 2026-05-12 00:00 |
09:19:13.92 |
-62:20:10.2 |
HIP 45856 |
12.62 |
| 2026-05-12 12:00 |
09:19:14.14 |
-62:19:43.0 |
HIP 45856 |
12.75 |
| 2026-05-13 00:00 |
09:19:14.39 |
-62:19:15.8 |
HIP 45856 |
12.89 |
| 2026-05-13 12:00 |
09:19:14.68 |
-62:18:48.7 |
HIP 45856 |
13.05 |
| 2026-05-14 00:00 |
09:19:15.00 |
-62:18:21.6 |
HIP 45856 |
13.21 |
| 2026-05-14 12:00 |
09:19:15.35 |
-62:17:54.6 |
HIP 45856 |
13.38 |
| 2026-05-15 00:00 |
09:19:15.73 |
-62:17:27.6 |
HIP 45856 |
13.57 |
| 2026-05-15 12:00 |
09:19:16.15 |
-62:17:00.6 |
HIP 45856 |
13.76 |
| 2026-05-16 00:00 |
09:19:16.60 |
-62:16:33.7 |
HIP 45856 |
13.96 |
| 2026-05-16 12:00 |
09:19:17.08 |
-62:16:06.9 |
HIP 45856 |
14.17 |
| 2026-05-17 00:00 |
09:19:17.60 |
-62:15:40.1 |
HIP 45856 |
14.38 |
| 2026-05-17 12:00 |
09:19:18.14 |
-62:15:13.3 |
HIP 45856 |
14.60 |
| 2026-05-18 00:00 |
09:19:18.72 |
-62:14:46.6 |
HIP 45856 |
14.83 |
| 2026-05-18 12:00 |
09:19:19.33 |
-62:14:20.0 |
HIP 45856 |
15.07 |
| 2026-05-19 00:00 |
09:19:19.98 |
-62:13:53.4 |
HIP 45856 |
15.31 |
| 2026-05-19 12:00 |
09:19:20.65 |
-62:13:26.9 |
HIP 45856 |
15.56 |
| 2026-05-20 00:00 |
09:19:21.36 |
-62:13:00.4 |
HIP 45817 |
15.75 |
| 2026-05-20 12:00 |
09:19:22.10 |
-62:12:34.0 |
HIP 45817 |
15.33 |
| 2026-05-21 00:00 |
09:19:22.87 |
-62:12:07.7 |
HIP 45817 |
14.92 |
| 2026-05-21 12:00 |
09:19:23.67 |
-62:11:41.5 |
HIP 45817 |
14.50 |
| 2026-05-22 00:00 |
09:19:24.51 |
-62:11:15.3 |
HIP 45817 |
14.08 |
| 2026-05-22 12:00 |
09:19:25.37 |
-62:10:49.2 |
HIP 45817 |
13.67 |
| 2026-05-23 00:00 |
09:19:26.27 |
-62:10:23.1 |
HIP 45817 |
13.25 |
| 2026-05-23 12:00 |
09:19:27.20 |
-62:09:57.2 |
HIP 45817 |
12.84 |
| 2026-05-24 00:00 |
09:19:28.16 |
-62:09:31.3 |
HIP 45817 |
12.42 |
| 2026-05-24 12:00 |
09:19:29.15 |
-62:09:05.5 |
HIP 45817 |
12.01 |
| 2026-05-25 00:00 |
09:19:30.17 |
-62:08:39.8 |
HIP 45817 |
11.60 |
| 2026-05-25 12:00 |
09:19:31.22 |
-62:08:14.1 |
HIP 45817 |
11.19 |
| 2026-05-26 00:00 |
09:19:32.30 |
-62:07:48.6 |
HIP 45817 |
10.79 |
| 2026-05-26 12:00 |
09:19:33.41 |
-62:07:23.1 |
HIP 45817 |
10.38 |
| 2026-05-27 00:00 |
09:19:34.56 |
-62:06:57.7 |
HIP 45817 |
9.98 |
| 2026-05-27 12:00 |
09:19:35.73 |
-62:06:32.4 |
HIP 45817 |
9.57 |
| 2026-05-28 00:00 |
09:19:36.93 |
-62:06:07.3 |
HIP 45817 |
9.17 |
| 2026-05-28 12:00 |
09:19:38.16 |
-62:05:42.2 |
HIP 45817 |
8.78 |
| 2026-05-29 00:00 |
09:19:39.43 |
-62:05:17.1 |
HIP 45817 |
8.38 |
| 2026-05-29 12:00 |
09:19:40.72 |
-62:04:52.2 |
HIP 45817 |
7.99 |
| 2026-05-30 00:00 |
09:19:42.04 |
-62:04:27.4 |
HIP 45817 |
7.61 |
| 2026-05-30 12:00 |
09:19:43.39 |
-62:04:02.7 |
HIP 45817 |
7.23 |
| 2026-05-31 00:00 |
09:19:44.77 |
-62:03:38.1 |
HIP 45817 |
6.85 |
| 2026-05-31 12:00 |
09:19:46.18 |
-62:03:13.6 |
HIP 45817 |
6.48 |
| 2026-06-01 00:00 |
09:19:47.62 |
-62:02:49.2 |
HIP 45817 |
6.12 |
| 2026-06-01 12:00 |
09:19:49.08 |
-62:02:24.9 |
HIP 45817 |
5.76 |
| 2026-06-02 00:00 |
09:19:50.58 |
-62:02:00.7 |
HIP 45817 |
5.42 |