メタデータ
| 項目 |
値 |
| Designation |
C/2017 S2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-08-29T08:08:37.178880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:35Z |
| Obs used |
67 |
| NEO |
- |
| M1 |
7.700 |
| K1 |
19.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-10-10.0000000 |
| e |
0.82311096 |
| q (au) |
3.614508 |
| a (au) |
20.433760 |
| i (deg) |
12.683350 |
| Ω (om, deg) |
62.427792 |
| ω (w, deg) |
305.972876 |
| M (ma, deg) |
0.444537 |
等級
散乱 + 全体線形
$$
M_a = (13.505 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.505 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.753 |
| k |
0.800 |
| 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) |
| 2026-05-12 00:00 |
10:05:27.88 |
+25:17:54.1 |
HIP 49353 |
13.80 |
| 2026-05-12 12:00 |
10:05:27.92 |
+25:17:30.8 |
HIP 49353 |
13.70 |
| 2026-05-13 00:00 |
10:05:28.03 |
+25:17:07.3 |
HIP 49353 |
13.63 |
| 2026-05-13 12:00 |
10:05:28.19 |
+25:16:43.5 |
HIP 49353 |
13.57 |
| 2026-05-14 00:00 |
10:05:28.41 |
+25:16:19.4 |
HIP 49353 |
13.54 |
| 2026-05-14 12:00 |
10:05:28.69 |
+25:15:55.1 |
HIP 49353 |
13.53 |
| 2026-05-15 00:00 |
10:05:29.02 |
+25:15:30.4 |
HIP 49353 |
13.55 |
| 2026-05-15 12:00 |
10:05:29.42 |
+25:15:05.5 |
HIP 49353 |
13.59 |
| 2026-05-16 00:00 |
10:05:29.87 |
+25:14:40.3 |
HIP 49353 |
13.66 |
| 2026-05-16 12:00 |
10:05:30.38 |
+25:14:14.8 |
HIP 49353 |
13.76 |
| 2026-05-17 00:00 |
10:05:30.95 |
+25:13:49.1 |
HIP 49353 |
13.88 |
| 2026-05-17 12:00 |
10:05:31.57 |
+25:13:23.0 |
HIP 49353 |
14.03 |
| 2026-05-18 00:00 |
10:05:32.25 |
+25:12:56.8 |
HIP 49353 |
14.21 |
| 2026-05-18 12:00 |
10:05:33.00 |
+25:12:30.2 |
HIP 49353 |
14.41 |
| 2026-05-19 00:00 |
10:05:33.79 |
+25:12:03.4 |
HIP 49353 |
14.63 |
| 2026-05-19 12:00 |
10:05:34.65 |
+25:11:36.3 |
HIP 49353 |
14.89 |
| 2026-05-20 00:00 |
10:05:35.56 |
+25:11:08.9 |
HIP 49353 |
15.17 |
| 2026-05-20 12:00 |
10:05:36.53 |
+25:10:41.3 |
HIP 49353 |
15.47 |
| 2026-05-21 00:00 |
10:05:37.56 |
+25:10:13.5 |
HIP 49353 |
15.80 |
| 2026-05-21 12:00 |
10:05:38.64 |
+25:09:45.4 |
HIP 49353 |
16.15 |
| 2026-05-22 00:00 |
10:05:39.78 |
+25:09:17.0 |
HIP 49353 |
16.52 |
| 2026-05-22 12:00 |
10:05:40.98 |
+25:08:48.4 |
HIP 49353 |
16.92 |
| 2026-05-23 00:00 |
10:05:42.23 |
+25:08:19.5 |
HIP 49353 |
17.33 |
| 2026-05-23 12:00 |
10:05:43.54 |
+25:07:50.4 |
HIP 49353 |
17.77 |
| 2026-05-24 00:00 |
10:05:44.91 |
+25:07:21.1 |
HIP 49353 |
18.23 |
| 2026-05-24 12:00 |
10:05:46.33 |
+25:06:51.5 |
HIP 49430 |
18.05 |
| 2026-05-25 00:00 |
10:05:47.81 |
+25:06:21.7 |
HIP 49430 |
17.66 |
| 2026-05-25 12:00 |
10:05:49.34 |
+25:05:51.6 |
HIP 49430 |
17.28 |
| 2026-05-26 00:00 |
10:05:50.93 |
+25:05:21.3 |
HIP 49430 |
16.91 |
| 2026-05-26 12:00 |
10:05:52.57 |
+25:04:50.8 |
HIP 49430 |
16.56 |
| 2026-05-27 00:00 |
10:05:54.26 |
+25:04:20.1 |
HIP 49430 |
16.22 |
| 2026-05-27 12:00 |
10:05:56.02 |
+25:03:49.1 |
HIP 49430 |
15.91 |
| 2026-05-28 00:00 |
10:05:57.82 |
+25:03:17.9 |
HIP 49430 |
15.62 |
| 2026-05-28 12:00 |
10:05:59.68 |
+25:02:46.5 |
HIP 49430 |
15.35 |
| 2026-05-29 00:00 |
10:06:01.60 |
+25:02:14.9 |
HIP 49430 |
15.12 |
| 2026-05-29 12:00 |
10:06:03.57 |
+25:01:43.0 |
HIP 49430 |
14.91 |
| 2026-05-30 00:00 |
10:06:05.59 |
+25:01:10.9 |
HIP 49430 |
14.74 |
| 2026-05-30 12:00 |
10:06:07.66 |
+25:00:38.7 |
HIP 49430 |
14.61 |
| 2026-05-31 00:00 |
10:06:09.79 |
+25:00:06.2 |
HIP 49430 |
14.51 |
| 2026-05-31 12:00 |
10:06:11.98 |
+24:59:33.5 |
HIP 49430 |
14.46 |
| 2026-06-01 00:00 |
10:06:14.21 |
+24:59:00.6 |
HIP 49430 |
14.45 |
| 2026-06-01 12:00 |
10:06:16.50 |
+24:58:27.4 |
HIP 49430 |
14.49 |
| 2026-06-02 00:00 |
10:06:18.84 |
+24:57:54.1 |
HIP 49430 |
14.58 |