C/2018 F4 (PANSTARRS)
メタデータ
| 項目 |
値 |
| Designation |
C/2018 F4 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-12-04T01:26:15.930240Z |
| Orbit solution date (soln_date, UTC) |
2023-04-24T19:06:39Z |
| Obs used |
530 |
| NEO |
- |
| M1 |
5.300 |
| K1 |
13.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-03-17T12:40:26.976000Z |
| Discovery magnitude (MPC) |
20.40 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2019-09-20.0000000 |
| e |
1.00152144 |
| q (au) |
3.439968 |
| a (au) |
-2260.993631 |
| i (deg) |
78.098889 |
| Ω (om, deg) |
26.507082 |
| ω (w, deg) |
263.204195 |
| M (ma, deg) |
-0.000688 |
等級
散乱 + 全体線形
$$
M_a = (5.479 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
5.479 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.616 |
| 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 |
| 2018-03-17 |
2019-12-03 |
-4.5179 |
+3.714 |
| 2019-12-04 |
2020-09-08 |
+3.2670 |
-2.149 |
| 2020-09-08 |
2021-01-03 |
+3.3546 |
-2.816 |
| 2021-01-03 |
2021-11-06 |
+2.1461 |
-1.581 |
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 |
01:01:27.59 |
+36:16:55.5 |
HIP 4797 |
17.26 |
| 2026-02-03 12:00 |
01:01:31.18 |
+36:16:41.6 |
HIP 4797 |
16.98 |
| 2026-02-04 00:00 |
01:01:34.82 |
+36:16:28.2 |
HIP 4797 |
16.75 |
| 2026-02-04 12:00 |
01:01:38.53 |
+36:16:15.3 |
HIP 4797 |
16.55 |
| 2026-02-05 00:00 |
01:01:42.29 |
+36:16:02.9 |
HIP 4797 |
16.39 |
| 2026-02-05 12:00 |
01:01:46.11 |
+36:15:51.0 |
HIP 4797 |
16.29 |
| 2026-02-06 00:00 |
01:01:49.99 |
+36:15:39.7 |
HIP 4797 |
16.23 |
| 2026-02-06 12:00 |
01:01:53.93 |
+36:15:28.8 |
HIP 4797 |
16.23 |
| 2026-02-07 00:00 |
01:01:57.93 |
+36:15:18.5 |
HIP 4797 |
16.27 |
| 2026-02-07 12:00 |
01:02:01.98 |
+36:15:08.7 |
HIP 4797 |
16.37 |
| 2026-02-08 00:00 |
01:02:06.10 |
+36:14:59.4 |
HIP 4797 |
16.53 |
| 2026-02-08 12:00 |
01:02:10.26 |
+36:14:50.6 |
HIP 4797 |
16.73 |
| 2026-02-09 00:00 |
01:02:14.49 |
+36:14:42.4 |
HIP 4797 |
17.00 |
| 2026-02-09 12:00 |
01:02:18.77 |
+36:14:34.7 |
HIP 4797 |
17.31 |
| 2026-02-10 00:00 |
01:02:23.10 |
+36:14:27.5 |
HIP 4797 |
17.68 |
| 2026-02-10 12:00 |
01:02:27.49 |
+36:14:20.8 |
HIP 4797 |
18.09 |
| 2026-02-11 00:00 |
01:02:31.93 |
+36:14:14.6 |
HIP 4797 |
18.55 |
| 2026-02-11 12:00 |
01:02:36.43 |
+36:14:09.0 |
HIP 4797 |
19.06 |
| 2026-02-12 00:00 |
01:02:40.98 |
+36:14:03.9 |
HIP 4797 |
19.61 |
| 2026-02-12 12:00 |
01:02:45.59 |
+36:13:59.3 |
HIP 4797 |
20.20 |
| 2026-02-13 00:00 |
01:02:50.25 |
+36:13:55.2 |
HIP 4797 |
20.83 |
| 2026-02-13 12:00 |
01:02:54.96 |
+36:13:51.7 |
HIP 4797 |
21.50 |
| 2026-02-14 00:00 |
01:02:59.72 |
+36:13:48.7 |
HIP 4797 |
22.20 |
| 2026-02-14 12:00 |
01:03:04.54 |
+36:13:46.2 |
HIP 4797 |
22.94 |
| 2026-02-15 00:00 |
01:03:09.40 |
+36:13:44.3 |
HIP 4797 |
23.70 |
| 2026-02-15 12:00 |
01:03:14.32 |
+36:13:42.8 |
HIP 4797 |
24.50 |
| 2026-02-16 00:00 |
01:03:19.28 |
+36:13:41.9 |
HIP 4797 |
25.32 |
| 2026-02-16 12:00 |
01:03:24.30 |
+36:13:41.6 |
HIP 4797 |
26.17 |
| 2026-02-17 00:00 |
01:03:29.37 |
+36:13:41.7 |
HIP 4797 |
27.04 |
| 2026-02-17 12:00 |
01:03:34.48 |
+36:13:42.4 |
HIP 4797 |
27.93 |
| 2026-02-18 00:00 |
01:03:39.64 |
+36:13:43.6 |
HIP 4797 |
28.85 |
| 2026-02-18 12:00 |
01:03:44.85 |
+36:13:45.4 |
HIP 4797 |
29.79 |
| 2026-02-19 00:00 |
01:03:50.11 |
+36:13:47.6 |
HIP 4797 |
30.75 |
| 2026-02-19 12:00 |
01:03:55.42 |
+36:13:50.4 |
HIP 4797 |
31.72 |
| 2026-02-20 00:00 |
01:04:00.77 |
+36:13:53.7 |
HIP 4797 |
32.72 |
| 2026-02-20 12:00 |
01:04:06.17 |
+36:13:57.6 |
HIP 4797 |
33.73 |
| 2026-02-21 00:00 |
01:04:11.61 |
+36:14:02.0 |
HIP 4797 |
34.76 |
| 2026-02-21 12:00 |
01:04:17.10 |
+36:14:06.9 |
HIP 4797 |
35.81 |
| 2026-02-22 00:00 |
01:04:22.63 |
+36:14:12.3 |
HIP 4994 |
36.07 |
| 2026-02-22 12:00 |
01:04:28.21 |
+36:14:18.2 |
HIP 4994 |
36.13 |
| 2026-02-23 00:00 |
01:04:33.83 |
+36:14:24.7 |
HIP 4994 |
36.22 |
| 2026-02-23 12:00 |
01:04:39.49 |
+36:14:31.7 |
HIP 4994 |
36.33 |
| 2026-02-24 00:00 |
01:04:45.20 |
+36:14:39.2 |
HIP 4994 |
36.48 |