メタデータ
| 項目 |
値 |
| Designation |
C/2015 X5 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-12-31T00:50:40.139520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:20Z |
| Obs used |
227 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
10.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-07-11.0000000 |
| e |
1.00304318 |
| q (au) |
6.801746 |
| a (au) |
-2235.080422 |
| i (deg) |
124.284533 |
| Ω (om, deg) |
122.311473 |
| ω (w, deg) |
27.750506 |
| M (ma, deg) |
-0.001614 |
等級
散乱 + 全体線形
$$
M_a = (6.073 + 3.992\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
6.073 |
| n |
3.992 |
| gf |
0.977 |
| gb |
-0.739 |
| k |
1.000 |
| δ90 |
9.974 |
| 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 |
| 2015-12-06 |
2017-12-23 |
+1.9144 |
-1.449 |
| 2018-01-05 |
2020-02-14 |
-8.6346 |
+7.072 |
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) |
| 2026-09-20 00:00 |
21:15:01.93 |
+23:43:22.7 |
HIP 104949 |
14.65 |
| 2026-09-20 12:00 |
21:14:56.57 |
+23:42:08.6 |
HIP 104949 |
14.24 |
| 2026-09-21 00:00 |
21:14:51.25 |
+23:40:54.2 |
HIP 104949 |
14.03 |
| 2026-09-21 12:00 |
21:14:45.97 |
+23:39:39.6 |
HIP 104949 |
14.03 |
| 2026-09-22 00:00 |
21:14:40.74 |
+23:38:24.7 |
HIP 104949 |
14.23 |
| 2026-09-22 12:00 |
21:14:35.55 |
+23:37:09.7 |
HIP 104949 |
14.63 |
| 2026-09-23 00:00 |
21:14:30.40 |
+23:35:54.4 |
HIP 104949 |
15.20 |
| 2026-09-23 12:00 |
21:14:25.29 |
+23:34:38.9 |
HIP 104949 |
15.92 |
| 2026-09-24 00:00 |
21:14:20.23 |
+23:33:23.2 |
HIP 104949 |
16.79 |
| 2026-09-24 12:00 |
21:14:15.21 |
+23:32:07.3 |
HIP 104949 |
17.76 |
| 2026-09-25 00:00 |
21:14:10.24 |
+23:30:51.2 |
HIP 104949 |
18.83 |
| 2026-09-25 12:00 |
21:14:05.31 |
+23:29:34.9 |
HIP 104949 |
19.98 |
| 2026-09-26 00:00 |
21:14:00.43 |
+23:28:18.5 |
HIP 104949 |
21.19 |
| 2026-09-26 12:00 |
21:13:55.59 |
+23:27:01.8 |
HIP 104949 |
22.46 |
| 2026-09-27 00:00 |
21:13:50.80 |
+23:25:45.0 |
HIP 104949 |
23.77 |
| 2026-09-27 12:00 |
21:13:46.06 |
+23:24:28.0 |
HIP 104949 |
25.12 |
| 2026-09-28 00:00 |
21:13:41.36 |
+23:23:10.9 |
HIP 104949 |
26.49 |
| 2026-09-28 12:00 |
21:13:36.71 |
+23:21:53.6 |
HIP 104949 |
27.89 |
| 2026-09-29 00:00 |
21:13:32.10 |
+23:20:36.1 |
HIP 104648 |
27.35 |
| 2026-09-29 12:00 |
21:13:27.55 |
+23:19:18.5 |
HIP 104648 |
25.75 |
| 2026-09-30 00:00 |
21:13:23.04 |
+23:18:00.8 |
HIP 104648 |
24.17 |
| 2026-09-30 12:00 |
21:13:18.57 |
+23:16:42.9 |
HIP 104648 |
22.62 |
| 2026-10-01 00:00 |
21:13:14.16 |
+23:15:24.8 |
HIP 104648 |
21.08 |
| 2026-10-01 12:00 |
21:13:09.79 |
+23:14:06.7 |
HIP 104648 |
19.57 |
| 2026-10-02 00:00 |
21:13:05.48 |
+23:12:48.4 |
HIP 104648 |
18.09 |
| 2026-10-02 12:00 |
21:13:01.21 |
+23:11:30.0 |
HIP 104648 |
16.65 |
| 2026-10-03 00:00 |
21:12:56.99 |
+23:10:11.5 |
HIP 104648 |
15.26 |
| 2026-10-03 12:00 |
21:12:52.82 |
+23:08:52.9 |
HIP 104648 |
13.93 |
| 2026-10-04 00:00 |
21:12:48.70 |
+23:07:34.1 |
HIP 104648 |
12.68 |
| 2026-10-04 12:00 |
21:12:44.63 |
+23:06:15.3 |
HIP 104648 |
11.54 |
| 2026-10-05 00:00 |
21:12:40.61 |
+23:04:56.4 |
HIP 104648 |
10.53 |
| 2026-10-05 12:00 |
21:12:36.64 |
+23:03:37.4 |
HIP 104648 |
9.69 |
| 2026-10-06 00:00 |
21:12:32.72 |
+23:02:18.3 |
HIP 104648 |
9.08 |
| 2026-10-06 12:00 |
21:12:28.86 |
+23:00:59.1 |
HIP 104648 |
8.72 |
| 2026-10-07 00:00 |
21:12:25.04 |
+22:59:39.9 |
HIP 104648 |
8.66 |
| 2026-10-07 12:00 |
21:12:21.28 |
+22:58:20.6 |
HIP 104648 |
8.90 |
| 2026-10-08 00:00 |
21:12:17.57 |
+22:57:01.2 |
HIP 104648 |
9.41 |
| 2026-10-08 12:00 |
21:12:13.91 |
+22:55:41.8 |
HIP 104648 |
10.14 |
| 2026-10-09 00:00 |
21:12:10.30 |
+22:54:22.4 |
HIP 104648 |
11.05 |
| 2026-10-09 12:00 |
21:12:06.75 |
+22:53:02.9 |
HIP 104648 |
12.10 |
| 2026-10-10 00:00 |
21:12:03.25 |
+22:51:43.4 |
HIP 104648 |
13.26 |
| 2026-10-10 12:00 |
21:11:59.80 |
+22:50:23.8 |
HIP 104648 |
14.49 |
| 2026-10-11 00:00 |
21:11:56.40 |
+22:49:04.2 |
HIP 104648 |
15.77 |