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) |
| 2026-05-12 00:00 |
11:05:49.81 |
-59:34:22.8 |
HIP 54184 |
10.28 |
| 2026-05-12 12:00 |
11:05:46.37 |
-59:33:14.2 |
HIP 54184 |
11.02 |
| 2026-05-13 00:00 |
11:05:43.02 |
-59:32:05.5 |
HIP 54184 |
11.84 |
| 2026-05-13 12:00 |
11:05:39.76 |
-59:30:56.7 |
HIP 54184 |
12.74 |
| 2026-05-14 00:00 |
11:05:36.58 |
-59:29:47.7 |
HIP 54184 |
13.69 |
| 2026-05-14 12:00 |
11:05:33.49 |
-59:28:38.6 |
HIP 54184 |
14.68 |
| 2026-05-15 00:00 |
11:05:30.50 |
-59:27:29.5 |
HIP 54184 |
15.71 |
| 2026-05-15 12:00 |
11:05:27.59 |
-59:26:20.2 |
HIP 54184 |
16.77 |
| 2026-05-16 00:00 |
11:05:24.76 |
-59:25:10.7 |
HIP 54184 |
17.85 |
| 2026-05-16 12:00 |
11:05:22.03 |
-59:24:01.2 |
HIP 54184 |
18.95 |
| 2026-05-17 00:00 |
11:05:19.39 |
-59:22:51.7 |
HIP 54184 |
20.06 |
| 2026-05-17 12:00 |
11:05:16.83 |
-59:21:42.0 |
HIP 54184 |
21.19 |
| 2026-05-18 00:00 |
11:05:14.36 |
-59:20:32.2 |
HIP 54181 |
22.32 |
| 2026-05-18 12:00 |
11:05:11.99 |
-59:19:22.4 |
HIP 54062 |
23.41 |
| 2026-05-19 00:00 |
11:05:09.70 |
-59:18:12.6 |
HIP 54062 |
24.31 |
| 2026-05-19 12:00 |
11:05:07.50 |
-59:17:02.6 |
HIP 54062 |
25.25 |
| 2026-05-20 00:00 |
11:05:05.39 |
-59:15:52.7 |
HIP 54062 |
26.20 |
| 2026-05-20 12:00 |
11:05:03.37 |
-59:14:42.7 |
HIP 54062 |
27.19 |
| 2026-05-21 00:00 |
11:05:01.43 |
-59:13:32.6 |
HIP 54197 |
26.60 |
| 2026-05-21 12:00 |
11:04:59.59 |
-59:12:22.5 |
HIP 54197 |
25.45 |
| 2026-05-22 00:00 |
11:04:57.83 |
-59:11:12.5 |
HIP 54197 |
24.31 |
| 2026-05-22 12:00 |
11:04:56.17 |
-59:10:02.4 |
HIP 54197 |
23.17 |
| 2026-05-23 00:00 |
11:04:54.59 |
-59:08:52.2 |
HIP 54197 |
22.04 |
| 2026-05-23 12:00 |
11:04:53.10 |
-59:07:42.1 |
HIP 54197 |
20.90 |
| 2026-05-24 00:00 |
11:04:51.69 |
-59:06:32.0 |
HIP 54197 |
19.78 |
| 2026-05-24 12:00 |
11:04:50.38 |
-59:05:21.9 |
HIP 54197 |
18.66 |
| 2026-05-25 00:00 |
11:04:49.15 |
-59:04:11.9 |
HIP 54197 |
17.54 |
| 2026-05-25 12:00 |
11:04:48.02 |
-59:03:01.8 |
HIP 54197 |
16.43 |
| 2026-05-26 00:00 |
11:04:46.97 |
-59:01:51.8 |
HIP 54197 |
15.33 |
| 2026-05-26 12:00 |
11:04:46.00 |
-59:00:41.8 |
HIP 54197 |
14.24 |
| 2026-05-27 00:00 |
11:04:45.13 |
-58:59:31.9 |
HIP 54197 |
13.16 |
| 2026-05-27 12:00 |
11:04:44.34 |
-58:58:22.0 |
HIP 54197 |
12.09 |
| 2026-05-28 00:00 |
11:04:43.64 |
-58:57:12.1 |
HIP 54197 |
11.04 |
| 2026-05-28 12:00 |
11:04:43.03 |
-58:56:02.3 |
HIP 54197 |
10.01 |
| 2026-05-29 00:00 |
11:04:42.50 |
-58:54:52.6 |
HIP 54197 |
9.02 |
| 2026-05-29 12:00 |
11:04:42.06 |
-58:53:42.9 |
HIP 54197 |
8.06 |
| 2026-05-30 00:00 |
11:04:41.71 |
-58:52:33.4 |
HIP 54197 |
7.15 |
| 2026-05-30 12:00 |
11:04:41.44 |
-58:51:23.9 |
HIP 54147 |
6.09 |
| 2026-05-31 00:00 |
11:04:41.26 |
-58:50:14.5 |
HIP 54147 |
4.94 |
| 2026-05-31 12:00 |
11:04:41.16 |
-58:49:05.1 |
HIP 54147 |
3.80 |
| 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 |