メタデータ
| 項目 |
値 |
| Designation |
C/2017 Y1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-08-31T11:16:29.493120Z |
| Orbit solution date (soln_date, UTC) |
2022-07-06T03:12:22Z |
| Obs used |
92 |
| NEO |
- |
| M1 |
9.300 |
| K1 |
13.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-03-09.0000000 |
| e |
0.99901916 |
| q (au) |
3.718608 |
| a (au) |
3791.251402 |
| i (deg) |
55.240118 |
| Ω (om, deg) |
307.509679 |
| ω (w, deg) |
134.447483 |
| M (ma, deg) |
0.000800 |
等級
散乱 + 全体線形
$$
M_a = (9.514 + 4.991\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
9.514 |
| n |
4.991 |
| gf |
0.935 |
| gb |
-0.899 |
| k |
0.999 |
| δ90 |
5.121 |
| 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 |
11:04:41.16 |
-58:47:55.9 |
HIP 54147 |
2.67 |
| 2026-06-01 12:00 |
11:04:41.23 |
-58:46:46.8 |
HIP 54147 |
1.58 |
| 2026-06-02 00:00 |
11:04:41.40 |
-58:45:37.8 |
HIP 54147 |
0.76 |
| 2026-06-02 12:00 |
11:04:41.64 |
-58:44:28.9 |
HIP 54147 |
1.14 |
| 2026-06-03 00:00 |
11:04:41.98 |
-58:43:20.1 |
HIP 54147 |
2.16 |
| 2026-06-03 12:00 |
11:04:42.39 |
-58:42:11.4 |
HIP 54177 |
2.88 |
| 2026-06-04 00:00 |
11:04:42.90 |
-58:41:02.9 |
HIP 54177 |
2.07 |
| 2026-06-04 12:00 |
11:04:43.49 |
-58:39:54.5 |
HIP 54177 |
1.69 |
| 2026-06-05 00:00 |
11:04:44.16 |
-58:38:46.3 |
HIP 54177 |
1.99 |
| 2026-06-05 12:00 |
11:04:44.92 |
-58:37:38.2 |
HIP 54177 |
2.77 |
| 2026-06-06 00:00 |
11:04:45.76 |
-58:36:30.2 |
HIP 54174 |
3.56 |
| 2026-06-06 12:00 |
11:04:46.68 |
-58:35:22.4 |
HIP 54174 |
2.46 |
| 2026-06-07 00:00 |
11:04:47.69 |
-58:34:14.8 |
HIP 54174 |
1.41 |
| 2026-06-07 12:00 |
11:04:48.78 |
-58:33:07.3 |
HIP 54174 |
0.70 |
| 2026-06-08 00:00 |
11:04:49.96 |
-58:32:00.0 |
HIP 54174 |
1.25 |
| 2026-06-08 12:00 |
11:04:51.22 |
-58:30:52.9 |
HIP 54174 |
2.27 |
| 2026-06-09 00:00 |
11:04:52.56 |
-58:29:45.9 |
HIP 54174 |
3.36 |
| 2026-06-09 12:00 |
11:04:53.99 |
-58:28:39.2 |
HIP 54174 |
4.46 |
| 2026-06-10 00:00 |
11:04:55.50 |
-58:27:32.6 |
HIP 54174 |
5.58 |
| 2026-06-10 12:00 |
11:04:57.09 |
-58:26:26.3 |
HIP 54174 |
6.69 |
| 2026-06-11 00:00 |
11:04:58.76 |
-58:25:20.1 |
HIP 54174 |
7.81 |
| 2026-06-11 12:00 |
11:05:00.51 |
-58:24:14.2 |
HIP 54174 |
8.92 |
| 2026-06-12 00:00 |
11:05:02.35 |
-58:23:08.4 |
HIP 54174 |
10.03 |
| 2026-06-12 12:00 |
11:05:04.27 |
-58:22:02.9 |
HIP 54174 |
11.15 |
| 2026-06-13 00:00 |
11:05:06.27 |
-58:20:57.7 |
HIP 54174 |
12.26 |
| 2026-06-13 12:00 |
11:05:08.35 |
-58:19:52.6 |
HIP 54174 |
13.37 |
| 2026-06-14 00:00 |
11:05:10.51 |
-58:18:47.8 |
HIP 54174 |
14.48 |
| 2026-06-14 12:00 |
11:05:12.75 |
-58:17:43.2 |
HIP 54237 |
15.53 |
| 2026-06-15 00:00 |
11:05:15.08 |
-58:16:38.9 |
HIP 54237 |
16.47 |
| 2026-06-15 12:00 |
11:05:17.48 |
-58:15:34.9 |
HIP 54237 |
17.42 |
| 2026-06-16 00:00 |
11:05:19.96 |
-58:14:31.1 |
HIP 54237 |
18.39 |
| 2026-06-16 12:00 |
11:05:22.52 |
-58:13:27.5 |
HIP 54237 |
19.36 |
| 2026-06-17 00:00 |
11:05:25.16 |
-58:12:24.2 |
HIP 54082 |
18.80 |
| 2026-06-17 12:00 |
11:05:27.88 |
-58:11:21.3 |
HIP 54082 |
18.20 |
| 2026-06-18 00:00 |
11:05:30.68 |
-58:10:18.5 |
HIP 54082 |
17.66 |
| 2026-06-18 12:00 |
11:05:33.56 |
-58:09:16.1 |
HIP 54082 |
17.18 |
| 2026-06-19 00:00 |
11:05:36.51 |
-58:08:14.0 |
HIP 54082 |
16.77 |
| 2026-06-19 12:00 |
11:05:39.54 |
-58:07:12.1 |
HIP 54082 |
16.44 |
| 2026-06-20 00:00 |
11:05:42.65 |
-58:06:10.6 |
HIP 54082 |
16.19 |
| 2026-06-20 12:00 |
11:05:45.83 |
-58:05:09.3 |
HIP 54082 |
16.03 |
| 2026-06-21 00:00 |
11:05:49.09 |
-58:04:08.4 |
HIP 54082 |
15.95 |
| 2026-06-21 12:00 |
11:05:52.43 |
-58:03:07.8 |
HIP 54082 |
15.96 |
| 2026-06-22 00:00 |
11:05:55.84 |
-58:02:07.5 |
HIP 54082 |
16.05 |