メタデータ
| 項目 |
値 |
| Designation |
C/2013 W2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-01-05T06:10:39.014400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:43Z |
| Obs used |
179 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
13.750 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2015-01-20.0000000 |
| e |
0.57470690 |
| q (au) |
4.444439 |
| a (au) |
10.450297 |
| i (deg) |
4.567063 |
| Ω (om, deg) |
179.842795 |
| ω (w, deg) |
307.197933 |
| M (ma, deg) |
0.430116 |
等級
散乱 + 全体線形
$$
M_a = (5.108 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
5.108 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.734 |
| 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 |
| 2013-11-27 |
2014-10-24 |
+27.9138 |
-19.052 |
| 2015-01-17 |
2016-05-05 |
+3.0612 |
-2.167 |
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) |
| 2026-03-26 00:00 |
19:25:59.02 |
-17:23:27.9 |
HIP 95484 |
17.60 |
| 2026-03-26 12:00 |
19:26:02.81 |
-17:23:11.2 |
HIP 95484 |
18.32 |
| 2026-03-27 00:00 |
19:26:06.53 |
-17:22:54.6 |
HIP 95484 |
19.04 |
| 2026-03-27 12:00 |
19:26:10.19 |
-17:22:38.1 |
HIP 95484 |
19.77 |
| 2026-03-28 00:00 |
19:26:13.78 |
-17:22:21.7 |
HIP 95484 |
20.50 |
| 2026-03-28 12:00 |
19:26:17.30 |
-17:22:05.4 |
HIP 95484 |
21.24 |
| 2026-03-29 00:00 |
19:26:20.75 |
-17:21:49.2 |
HIP 95484 |
21.97 |
| 2026-03-29 12:00 |
19:26:24.14 |
-17:21:33.2 |
HIP 95484 |
22.70 |
| 2026-03-30 00:00 |
19:26:27.45 |
-17:21:17.2 |
HIP 95484 |
23.43 |
| 2026-03-30 12:00 |
19:26:30.70 |
-17:21:01.4 |
HIP 95484 |
24.15 |
| 2026-03-31 00:00 |
19:26:33.88 |
-17:20:45.7 |
HIP 95484 |
24.86 |
| 2026-03-31 12:00 |
19:26:37.00 |
-17:20:30.1 |
HIP 95484 |
25.57 |
| 2026-04-01 00:00 |
19:26:40.04 |
-17:20:14.6 |
HIP 95484 |
26.27 |
| 2026-04-01 12:00 |
19:26:43.01 |
-17:19:59.2 |
HIP 95484 |
26.95 |
| 2026-04-02 00:00 |
19:26:45.92 |
-17:19:44.0 |
HIP 95484 |
27.63 |
| 2026-04-02 12:00 |
19:26:48.75 |
-17:19:28.9 |
HIP 95484 |
28.30 |
| 2026-04-03 00:00 |
19:26:51.52 |
-17:19:13.9 |
HIP 95484 |
28.96 |
| 2026-04-03 12:00 |
19:26:54.22 |
-17:18:59.0 |
HIP 95484 |
29.60 |
| 2026-04-04 00:00 |
19:26:56.84 |
-17:18:44.3 |
HIP 95484 |
30.24 |
| 2026-04-04 12:00 |
19:26:59.40 |
-17:18:29.7 |
HIP 95484 |
30.86 |
| 2026-04-05 00:00 |
19:27:01.89 |
-17:18:15.2 |
HIP 95484 |
31.47 |
| 2026-04-05 12:00 |
19:27:04.31 |
-17:18:00.8 |
HIP 95610 |
31.31 |
| 2026-04-06 00:00 |
19:27:06.65 |
-17:17:46.6 |
HIP 95610 |
31.15 |
| 2026-04-06 12:00 |
19:27:08.93 |
-17:17:32.5 |
HIP 95610 |
31.01 |
| 2026-04-07 00:00 |
19:27:11.13 |
-17:17:18.5 |
HIP 95610 |
30.88 |
| 2026-04-07 12:00 |
19:27:13.27 |
-17:17:04.7 |
HIP 95610 |
30.76 |
| 2026-04-08 00:00 |
19:27:15.33 |
-17:16:51.0 |
HIP 95610 |
30.64 |
| 2026-04-08 12:00 |
19:27:17.32 |
-17:16:37.4 |
HIP 95610 |
30.54 |
| 2026-04-09 00:00 |
19:27:19.24 |
-17:16:24.0 |
HIP 95610 |
30.43 |
| 2026-04-09 12:00 |
19:27:21.09 |
-17:16:10.7 |
HIP 95610 |
30.34 |
| 2026-04-10 00:00 |
19:27:22.87 |
-17:15:57.6 |
HIP 95610 |
30.25 |
| 2026-04-10 12:00 |
19:27:24.57 |
-17:15:44.6 |
HIP 95610 |
30.16 |
| 2026-04-11 00:00 |
19:27:26.21 |
-17:15:31.7 |
HIP 95610 |
30.08 |
| 2026-04-11 12:00 |
19:27:27.77 |
-17:15:19.0 |
HIP 95610 |
30.00 |
| 2026-04-12 00:00 |
19:27:29.26 |
-17:15:06.4 |
HIP 95610 |
29.92 |
| 2026-04-12 12:00 |
19:27:30.67 |
-17:14:53.9 |
HIP 95610 |
29.85 |
| 2026-04-13 00:00 |
19:27:32.02 |
-17:14:41.6 |
HIP 95610 |
29.77 |
| 2026-04-13 12:00 |
19:27:33.29 |
-17:14:29.5 |
HIP 95610 |
29.70 |
| 2026-04-14 00:00 |
19:27:34.49 |
-17:14:17.5 |
HIP 95610 |
29.63 |
| 2026-04-14 12:00 |
19:27:35.62 |
-17:14:05.7 |
HIP 95610 |
29.55 |
| 2026-04-15 00:00 |
19:27:36.67 |
-17:13:54.0 |
HIP 95610 |
29.47 |
| 2026-04-15 12:00 |
19:27:37.65 |
-17:13:42.4 |
HIP 95610 |
29.40 |
| 2026-04-16 00:00 |
19:27:38.56 |
-17:13:31.0 |
HIP 95610 |
29.32 |