C/2017 T2 (PANSTARRS)
メタデータ
| 項目 |
値 |
| Designation |
C/2017 T2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-05-04T22:47:55.688640Z |
| Orbit solution date (soln_date, UTC) |
2024-07-30T14:57:25Z |
| Obs used |
6922 |
| NEO |
- |
| M1 |
10.200 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2019-12-13.0000000 |
| e |
0.99967750 |
| q (au) |
1.615095 |
| a (au) |
5008.050241 |
| i (deg) |
57.231440 |
| Ω (om, deg) |
64.378780 |
| ω (w, deg) |
92.993316 |
| M (ma, deg) |
359.999600 |
等級
散乱 + 全体線形
$$
M_a = (10.827 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.827 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-0.653 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2017-09-15 |
2019-08-05 |
+4.1328 |
-3.262 |
| 2019-08-05 |
2020-01-09 |
-1.8797 |
+0.423 |
| 2020-01-09 |
2020-05-04 |
+5.4565 |
-2.847 |
| 2020-05-05 |
2020-08-08 |
+15.7863 |
-4.493 |
| 2020-08-08 |
2021-10-04 |
+3.9198 |
-1.129 |
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 |
19:52:31.87 |
-64:29:05.9 |
HIP 97661 |
13.39 |
| 2026-02-03 12:00 |
19:52:48.54 |
-64:29:19.9 |
HIP 97661 |
14.99 |
| 2026-02-04 00:00 |
19:53:05.17 |
-64:29:34.3 |
HIP 97661 |
16.63 |
| 2026-02-04 12:00 |
19:53:21.77 |
-64:29:49.4 |
HIP 97661 |
18.30 |
| 2026-02-05 00:00 |
19:53:38.32 |
-64:30:04.9 |
HIP 97661 |
20.00 |
| 2026-02-05 12:00 |
19:53:54.83 |
-64:30:20.9 |
HIP 97661 |
21.71 |
| 2026-02-06 00:00 |
19:54:11.31 |
-64:30:37.5 |
HIP 97661 |
23.44 |
| 2026-02-06 12:00 |
19:54:27.74 |
-64:30:54.5 |
HIP 97661 |
25.17 |
| 2026-02-07 00:00 |
19:54:44.13 |
-64:31:12.1 |
HIP 97661 |
26.91 |
| 2026-02-07 12:00 |
19:55:00.48 |
-64:31:30.3 |
HIP 97661 |
28.66 |
| 2026-02-08 00:00 |
19:55:16.78 |
-64:31:48.9 |
HIP 97661 |
30.41 |
| 2026-02-08 12:00 |
19:55:33.04 |
-64:32:08.1 |
HIP 97661 |
32.16 |
| 2026-02-09 00:00 |
19:55:49.26 |
-64:32:27.7 |
HIP 98065 |
33.42 |
| 2026-02-09 12:00 |
19:56:05.43 |
-64:32:47.9 |
HIP 98065 |
33.80 |
| 2026-02-10 00:00 |
19:56:21.55 |
-64:33:08.7 |
HIP 98533 |
33.53 |
| 2026-02-10 12:00 |
19:56:37.63 |
-64:33:29.9 |
HIP 98533 |
31.84 |
| 2026-02-11 00:00 |
19:56:53.66 |
-64:33:51.7 |
HIP 98533 |
30.15 |
| 2026-02-11 12:00 |
19:57:09.64 |
-64:34:13.9 |
HIP 98533 |
28.48 |
| 2026-02-12 00:00 |
19:57:25.56 |
-64:34:36.8 |
HIP 98533 |
26.82 |
| 2026-02-12 12:00 |
19:57:41.44 |
-64:35:00.1 |
HIP 98533 |
25.17 |
| 2026-02-13 00:00 |
19:57:57.27 |
-64:35:23.9 |
HIP 98533 |
23.53 |
| 2026-02-13 12:00 |
19:58:13.05 |
-64:35:48.3 |
HIP 98533 |
21.91 |
| 2026-02-14 00:00 |
19:58:28.77 |
-64:36:13.2 |
HIP 98533 |
20.31 |
| 2026-02-14 12:00 |
19:58:44.44 |
-64:36:38.6 |
HIP 98533 |
18.72 |
| 2026-02-15 00:00 |
19:59:00.05 |
-64:37:04.6 |
HIP 98533 |
17.17 |
| 2026-02-15 12:00 |
19:59:15.61 |
-64:37:31.0 |
HIP 98533 |
15.65 |
| 2026-02-16 00:00 |
19:59:31.11 |
-64:37:58.0 |
HIP 98533 |
14.17 |
| 2026-02-16 12:00 |
19:59:46.56 |
-64:38:25.5 |
HIP 98533 |
12.76 |
| 2026-02-17 00:00 |
20:00:01.95 |
-64:38:53.6 |
HIP 98533 |
11.42 |
| 2026-02-17 12:00 |
20:00:17.27 |
-64:39:22.1 |
HIP 98533 |
10.18 |
| 2026-02-18 00:00 |
20:00:32.54 |
-64:39:51.2 |
HIP 98533 |
9.09 |
| 2026-02-18 12:00 |
20:00:47.75 |
-64:40:20.8 |
HIP 98533 |
8.21 |
| 2026-02-19 00:00 |
20:01:02.90 |
-64:40:50.9 |
HIP 98533 |
7.59 |
| 2026-02-19 12:00 |
20:01:17.99 |
-64:41:21.5 |
HIP 98533 |
7.32 |
| 2026-02-20 00:00 |
20:01:33.01 |
-64:41:52.7 |
HIP 98533 |
7.41 |
| 2026-02-20 12:00 |
20:01:47.97 |
-64:42:24.4 |
HIP 98533 |
7.87 |
| 2026-02-21 00:00 |
20:02:02.87 |
-64:42:56.5 |
HIP 98533 |
8.62 |
| 2026-02-21 12:00 |
20:02:17.70 |
-64:43:29.2 |
HIP 98533 |
9.59 |
| 2026-02-22 00:00 |
20:02:32.46 |
-64:44:02.5 |
HIP 98533 |
10.73 |
| 2026-02-22 12:00 |
20:02:47.16 |
-64:44:36.2 |
HIP 98533 |
11.98 |
| 2026-02-23 00:00 |
20:03:01.79 |
-64:45:10.4 |
HIP 98533 |
13.31 |
| 2026-02-23 12:00 |
20:03:16.35 |
-64:45:45.2 |
HIP 98533 |
14.70 |
| 2026-02-24 00:00 |
20:03:30.85 |
-64:46:20.5 |
HIP 98533 |
16.13 |