メタデータ
| 項目 |
値 |
| Designation |
C/2019 F2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-09-08T21:26:06.544320Z |
| Orbit solution date (soln_date, UTC) |
2025-09-09T12:42:31Z |
| Obs used |
683 |
| NEO |
- |
| M1 |
5.300 |
| K1 |
24.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2019-03-26T07:21:56.332800Z |
| Discovery magnitude (MPC) |
17.58 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2019-05-07.0000000 |
| e |
0.86507120 |
| q (au) |
2.232882 |
| a (au) |
16.548594 |
| i (deg) |
19.188643 |
| Ω (om, deg) |
175.867930 |
| ω (w, deg) |
10.953986 |
| M (ma, deg) |
358.171475 |
等級
散乱 + 全体線形
$$
M_a = (8.336 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.336 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.501 |
| 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 |
| 2019-02-26 |
2019-04-23 |
+11.7951 |
-5.190 |
| 2019-04-23 |
2019-06-26 |
+19.2752 |
-8.502 |
| 2019-12-28 |
2020-07-20 |
+5.9715 |
-2.763 |
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 |
22:17:13.24 |
-03:13:39.2 |
HIP 110106 |
15.30 |
| 2026-09-20 12:00 |
22:17:07.64 |
-03:14:22.9 |
HIP 110106 |
16.83 |
| 2026-09-21 00:00 |
22:17:02.07 |
-03:15:06.6 |
HIP 110106 |
18.35 |
| 2026-09-21 12:00 |
22:16:56.53 |
-03:15:50.2 |
HIP 110106 |
19.88 |
| 2026-09-22 00:00 |
22:16:51.02 |
-03:16:33.7 |
HIP 110106 |
21.41 |
| 2026-09-22 12:00 |
22:16:45.55 |
-03:17:17.2 |
HIP 110106 |
22.92 |
| 2026-09-23 00:00 |
22:16:40.11 |
-03:18:00.5 |
HIP 110106 |
24.44 |
| 2026-09-23 12:00 |
22:16:34.70 |
-03:18:43.8 |
HIP 110106 |
25.95 |
| 2026-09-24 00:00 |
22:16:29.32 |
-03:19:27.0 |
HIP 110106 |
27.45 |
| 2026-09-24 12:00 |
22:16:23.98 |
-03:20:10.1 |
HIP 110106 |
28.95 |
| 2026-09-25 00:00 |
22:16:18.68 |
-03:20:53.1 |
HIP 110106 |
30.44 |
| 2026-09-25 12:00 |
22:16:13.41 |
-03:21:36.0 |
HIP 110106 |
31.92 |
| 2026-09-26 00:00 |
22:16:08.17 |
-03:22:18.8 |
HIP 110106 |
33.40 |
| 2026-09-26 12:00 |
22:16:02.97 |
-03:23:01.5 |
HIP 110106 |
34.86 |
| 2026-09-27 00:00 |
22:15:57.81 |
-03:23:44.1 |
HIP 110106 |
36.32 |
| 2026-09-27 12:00 |
22:15:52.68 |
-03:24:26.6 |
HIP 110106 |
37.77 |
| 2026-09-28 00:00 |
22:15:47.59 |
-03:25:08.9 |
HIP 109733 |
37.90 |
| 2026-09-28 12:00 |
22:15:42.54 |
-03:25:51.2 |
HIP 109733 |
36.46 |
| 2026-09-29 00:00 |
22:15:37.53 |
-03:26:33.3 |
HIP 109733 |
35.03 |
| 2026-09-29 12:00 |
22:15:32.56 |
-03:27:15.3 |
HIP 109733 |
33.61 |
| 2026-09-30 00:00 |
22:15:27.62 |
-03:27:57.1 |
HIP 109733 |
32.21 |
| 2026-09-30 12:00 |
22:15:22.73 |
-03:28:38.9 |
HIP 109733 |
30.81 |
| 2026-10-01 00:00 |
22:15:17.87 |
-03:29:20.5 |
HIP 109733 |
29.42 |
| 2026-10-01 12:00 |
22:15:13.06 |
-03:30:01.9 |
HIP 109733 |
28.04 |
| 2026-10-02 00:00 |
22:15:08.29 |
-03:30:43.2 |
HIP 109733 |
26.67 |
| 2026-10-02 12:00 |
22:15:03.55 |
-03:31:24.4 |
HIP 109733 |
25.32 |
| 2026-10-03 00:00 |
22:14:58.86 |
-03:32:05.4 |
HIP 109733 |
23.97 |
| 2026-10-03 12:00 |
22:14:54.22 |
-03:32:46.2 |
HIP 109733 |
22.63 |
| 2026-10-04 00:00 |
22:14:49.61 |
-03:33:27.0 |
HIP 109733 |
21.31 |
| 2026-10-04 12:00 |
22:14:45.05 |
-03:34:07.5 |
HIP 109733 |
20.00 |
| 2026-10-05 00:00 |
22:14:40.54 |
-03:34:47.9 |
HIP 109733 |
18.70 |
| 2026-10-05 12:00 |
22:14:36.06 |
-03:35:28.1 |
HIP 109733 |
17.41 |
| 2026-10-06 00:00 |
22:14:31.64 |
-03:36:08.1 |
HIP 109733 |
16.13 |
| 2026-10-06 12:00 |
22:14:27.25 |
-03:36:48.0 |
HIP 109733 |
14.87 |
| 2026-10-07 00:00 |
22:14:22.92 |
-03:37:27.7 |
HIP 109733 |
13.62 |
| 2026-10-07 12:00 |
22:14:18.62 |
-03:38:07.2 |
HIP 109733 |
12.39 |
| 2026-10-08 00:00 |
22:14:14.38 |
-03:38:46.5 |
HIP 109733 |
11.17 |
| 2026-10-08 12:00 |
22:14:10.18 |
-03:39:25.6 |
HIP 109733 |
9.96 |
| 2026-10-09 00:00 |
22:14:06.03 |
-03:40:04.6 |
HIP 109733 |
8.78 |
| 2026-10-09 12:00 |
22:14:01.93 |
-03:40:43.3 |
HIP 109733 |
7.62 |
| 2026-10-10 00:00 |
22:13:57.88 |
-03:41:21.9 |
HIP 109733 |
6.49 |
| 2026-10-10 12:00 |
22:13:53.87 |
-03:42:00.2 |
HIP 109733 |
5.39 |
| 2026-10-11 00:00 |
22:13:49.92 |
-03:42:38.4 |
HIP 109733 |
4.35 |