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) |
| 2026-09-25 00:00 |
09:31:50.95 |
-61:50:48.3 |
HIP 46622 |
10.77 |
| 2026-09-25 12:00 |
09:31:53.73 |
-61:51:08.7 |
HIP 46622 |
11.18 |
| 2026-09-26 00:00 |
09:31:56.50 |
-61:51:29.2 |
HIP 46622 |
11.60 |
| 2026-09-26 12:00 |
09:31:59.24 |
-61:51:49.8 |
HIP 46622 |
12.02 |
| 2026-09-27 00:00 |
09:32:01.96 |
-61:52:10.7 |
HIP 46622 |
12.44 |
| 2026-09-27 12:00 |
09:32:04.67 |
-61:52:31.6 |
HIP 46622 |
12.86 |
| 2026-09-28 00:00 |
09:32:07.35 |
-61:52:52.7 |
HIP 46622 |
13.29 |
| 2026-09-28 12:00 |
09:32:10.01 |
-61:53:14.0 |
HIP 46622 |
13.72 |
| 2026-09-29 00:00 |
09:32:12.65 |
-61:53:35.4 |
HIP 46622 |
14.15 |
| 2026-09-29 12:00 |
09:32:15.26 |
-61:53:57.0 |
HIP 46622 |
14.58 |
| 2026-09-30 00:00 |
09:32:17.86 |
-61:54:18.7 |
HIP 46622 |
15.01 |
| 2026-09-30 12:00 |
09:32:20.43 |
-61:54:40.6 |
HIP 46622 |
15.44 |
| 2026-10-01 00:00 |
09:32:22.98 |
-61:55:02.6 |
HIP 46622 |
15.88 |
| 2026-10-01 12:00 |
09:32:25.51 |
-61:55:24.7 |
HIP 46622 |
16.31 |
| 2026-10-02 00:00 |
09:32:28.01 |
-61:55:47.0 |
HIP 46622 |
16.75 |
| 2026-10-02 12:00 |
09:32:30.49 |
-61:56:09.5 |
HIP 46622 |
17.18 |
| 2026-10-03 00:00 |
09:32:32.95 |
-61:56:32.0 |
HIP 46622 |
17.62 |
| 2026-10-03 12:00 |
09:32:35.39 |
-61:56:54.8 |
HIP 46622 |
18.06 |
| 2026-10-04 00:00 |
09:32:37.80 |
-61:57:17.6 |
HIP 46622 |
18.50 |
| 2026-10-04 12:00 |
09:32:40.19 |
-61:57:40.6 |
HIP 46622 |
18.94 |
| 2026-10-05 00:00 |
09:32:42.55 |
-61:58:03.7 |
HIP 46622 |
19.38 |
| 2026-10-05 12:00 |
09:32:44.89 |
-61:58:27.0 |
HIP 46622 |
19.82 |
| 2026-10-06 00:00 |
09:32:47.20 |
-61:58:50.4 |
HIP 46622 |
20.26 |
| 2026-10-06 12:00 |
09:32:49.49 |
-61:59:13.9 |
HIP 46622 |
20.70 |
| 2026-10-07 00:00 |
09:32:51.76 |
-61:59:37.5 |
HIP 46622 |
21.14 |
| 2026-10-07 12:00 |
09:32:54.00 |
-62:00:01.3 |
HIP 46622 |
21.58 |
| 2026-10-08 00:00 |
09:32:56.22 |
-62:00:25.2 |
HIP 46622 |
22.02 |
| 2026-10-08 12:00 |
09:32:58.41 |
-62:00:49.2 |
HIP 46622 |
22.46 |
| 2026-10-09 00:00 |
09:33:00.57 |
-62:01:13.4 |
HIP 46622 |
22.90 |
| 2026-10-09 12:00 |
09:33:02.71 |
-62:01:37.6 |
HIP 46622 |
23.34 |
| 2026-10-10 00:00 |
09:33:04.82 |
-62:02:02.0 |
HIP 46622 |
23.78 |
| 2026-10-10 12:00 |
09:33:06.91 |
-62:02:26.5 |
HIP 46622 |
24.22 |
| 2026-10-11 00:00 |
09:33:08.97 |
-62:02:51.1 |
HIP 47068 |
24.49 |
| 2026-10-11 12:00 |
09:33:11.00 |
-62:03:15.9 |
HIP 47068 |
24.63 |
| 2026-10-12 00:00 |
09:33:13.01 |
-62:03:40.7 |
HIP 47068 |
24.78 |
| 2026-10-12 12:00 |
09:33:14.99 |
-62:04:05.7 |
HIP 47068 |
24.94 |
| 2026-10-13 00:00 |
09:33:16.94 |
-62:04:30.7 |
HIP 47068 |
25.12 |
| 2026-10-13 12:00 |
09:33:18.86 |
-62:04:55.9 |
HIP 47068 |
25.30 |
| 2026-10-14 00:00 |
09:33:20.76 |
-62:05:21.2 |
HIP 47068 |
25.49 |
| 2026-10-14 12:00 |
09:33:22.63 |
-62:05:46.5 |
HIP 47068 |
25.70 |
| 2026-10-15 00:00 |
09:33:24.47 |
-62:06:12.0 |
HIP 47063 |
25.76 |
| 2026-10-15 12:00 |
09:33:26.29 |
-62:06:37.6 |
HIP 47063 |
25.28 |
| 2026-10-16 00:00 |
09:33:28.08 |
-62:07:03.2 |
HIP 47063 |
24.81 |