C/2017 X1 (PANSTARRS)
メタデータ
| 項目 |
値 |
| Designation |
C/2017 X1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-06-14T10:45:05.999040Z |
| Orbit solution date (soln_date, UTC) |
2021-09-04T23:42:57Z |
| Obs used |
127 |
| NEO |
- |
| M1 |
7.000 |
| K1 |
13.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-02-14.0000000 |
| e |
0.85110910 |
| q (au) |
4.662645 |
| a (au) |
31.315852 |
| i (deg) |
31.310998 |
| Ω (om, deg) |
251.126772 |
| ω (w, deg) |
283.106326 |
| M (ma, deg) |
359.322581 |
等級
散乱 + 全体線形
$$
M_a = (5.561 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
5.561 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
1.000 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2017-02-12 |
2018-06-07 |
+17.3813 |
-12.086 |
| 2018-07-17 |
2019-07-25 |
-2.0175 |
+1.329 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
19:33:04.39 |
-00:09:06.8 |
HIP 96193 |
11.03 |
| 2026-02-03 12:00 |
19:33:11.72 |
-00:08:28.5 |
HIP 96193 |
10.36 |
| 2026-02-04 00:00 |
19:33:19.02 |
-00:07:50.0 |
HIP 96193 |
10.03 |
| 2026-02-04 12:00 |
19:33:26.30 |
-00:07:11.1 |
HIP 96193 |
10.07 |
| 2026-02-05 00:00 |
19:33:33.55 |
-00:06:32.1 |
HIP 96193 |
10.48 |
| 2026-02-05 12:00 |
19:33:40.78 |
-00:05:52.7 |
HIP 96193 |
11.21 |
| 2026-02-06 00:00 |
19:33:47.99 |
-00:05:13.1 |
HIP 96193 |
12.21 |
| 2026-02-06 12:00 |
19:33:55.17 |
-00:04:33.3 |
HIP 96193 |
13.41 |
| 2026-02-07 00:00 |
19:34:02.33 |
-00:03:53.2 |
HIP 96193 |
14.77 |
| 2026-02-07 12:00 |
19:34:09.47 |
-00:03:12.9 |
HIP 96193 |
16.23 |
| 2026-02-08 00:00 |
19:34:16.57 |
-00:02:32.3 |
HIP 96193 |
17.78 |
| 2026-02-08 12:00 |
19:34:23.66 |
-00:01:51.5 |
HIP 96193 |
19.39 |
| 2026-02-09 00:00 |
19:34:30.71 |
-00:01:10.4 |
HIP 96193 |
21.05 |
| 2026-02-09 12:00 |
19:34:37.74 |
-00:00:29.2 |
HIP 96402 |
21.58 |
| 2026-02-10 00:00 |
19:34:44.74 |
+00:00:12.4 |
HIP 96402 |
19.71 |
| 2026-02-10 12:00 |
19:34:51.72 |
+00:00:54.1 |
HIP 96402 |
17.85 |
| 2026-02-11 00:00 |
19:34:58.67 |
+00:01:36.1 |
HIP 96402 |
15.99 |
| 2026-02-11 12:00 |
19:35:05.58 |
+00:02:18.4 |
HIP 96402 |
14.14 |
| 2026-02-12 00:00 |
19:35:12.47 |
+00:03:00.8 |
HIP 96402 |
12.31 |
| 2026-02-12 12:00 |
19:35:19.33 |
+00:03:43.5 |
HIP 96402 |
10.49 |
| 2026-02-13 00:00 |
19:35:26.16 |
+00:04:26.4 |
HIP 96402 |
8.69 |
| 2026-02-13 12:00 |
19:35:32.97 |
+00:05:09.6 |
HIP 96402 |
6.93 |
| 2026-02-14 00:00 |
19:35:39.74 |
+00:05:52.9 |
HIP 96402 |
5.24 |
| 2026-02-14 12:00 |
19:35:46.48 |
+00:06:36.5 |
HIP 96402 |
3.71 |
| 2026-02-15 00:00 |
19:35:53.19 |
+00:07:20.3 |
HIP 96402 |
2.60 |
| 2026-02-15 12:00 |
19:35:59.86 |
+00:08:04.3 |
HIP 96402 |
2.55 |
| 2026-02-16 00:00 |
19:36:06.51 |
+00:08:48.5 |
HIP 96402 |
3.59 |
| 2026-02-16 12:00 |
19:36:13.12 |
+00:09:32.9 |
HIP 96402 |
5.09 |
| 2026-02-17 00:00 |
19:36:19.70 |
+00:10:17.5 |
HIP 96403 |
6.62 |
| 2026-02-17 12:00 |
19:36:26.25 |
+00:11:02.4 |
HIP 96403 |
7.44 |
| 2026-02-18 00:00 |
19:36:32.76 |
+00:11:47.4 |
HIP 96403 |
8.56 |
| 2026-02-18 12:00 |
19:36:39.24 |
+00:12:32.7 |
HIP 96403 |
9.87 |
| 2026-02-19 00:00 |
19:36:45.69 |
+00:13:18.1 |
HIP 96403 |
11.30 |
| 2026-02-19 12:00 |
19:36:52.10 |
+00:14:03.7 |
HIP 96403 |
12.81 |
| 2026-02-20 00:00 |
19:36:58.47 |
+00:14:49.5 |
HIP 96403 |
14.37 |
| 2026-02-20 12:00 |
19:37:04.81 |
+00:15:35.5 |
HIP 96403 |
15.97 |
| 2026-02-21 00:00 |
19:37:11.12 |
+00:16:21.7 |
HIP 96403 |
17.58 |
| 2026-02-21 12:00 |
19:37:17.38 |
+00:17:08.1 |
HIP 96603 |
16.47 |
| 2026-02-22 00:00 |
19:37:23.61 |
+00:17:54.7 |
HIP 96603 |
14.79 |
| 2026-02-22 12:00 |
19:37:29.81 |
+00:18:41.4 |
HIP 96603 |
13.13 |
| 2026-02-23 00:00 |
19:37:35.97 |
+00:19:28.4 |
HIP 96603 |
11.50 |
| 2026-02-23 12:00 |
19:37:42.09 |
+00:20:15.5 |
HIP 96603 |
9.91 |
| 2026-02-24 00:00 |
19:37:48.17 |
+00:21:02.7 |
HIP 96603 |
8.39 |