メタデータ
| 項目 |
値 |
| Designation |
C/2018 L2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-12-02T13:55:55.485120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:44Z |
| Obs used |
731 |
| NEO |
- |
| M1 |
9.500 |
| K1 |
10.750 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-06-06T07:58:35.040000Z |
| Discovery magnitude (MPC) |
15.60 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) |
2018-12-29.0000000 |
| e |
0.99298130 |
| q (au) |
1.711711 |
| a (au) |
243.878556 |
| i (deg) |
67.423590 |
| Ω (om, deg) |
243.018259 |
| ω (w, deg) |
56.230818 |
| M (ma, deg) |
0.006837 |
等級
散乱 + 全体線形
$$
M_a = (8.836 + 4.978\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.836 |
| n |
4.978 |
| gf |
1.000 |
| gb |
-0.767 |
| k |
0.985 |
| 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 |
| 2018-06-04 |
2018-09-08 |
+4.1202 |
-1.557 |
| 2018-09-08 |
2018-12-01 |
+25.5943 |
-7.920 |
| 2018-12-03 |
2020-01-20 |
+2.8927 |
-2.045 |
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) |
| 2026-07-29 00:00 |
05:02:46.51 |
+02:13:13.7 |
HIP 23448 |
11.52 |
| 2026-07-29 12:00 |
05:02:50.38 |
+02:12:49.1 |
HIP 23448 |
11.63 |
| 2026-07-30 00:00 |
05:02:54.22 |
+02:12:24.2 |
HIP 23448 |
11.82 |
| 2026-07-30 12:00 |
05:02:58.02 |
+02:11:59.2 |
HIP 23448 |
12.09 |
| 2026-07-31 00:00 |
05:03:01.78 |
+02:11:33.9 |
HIP 23448 |
12.43 |
| 2026-07-31 12:00 |
05:03:05.52 |
+02:11:08.3 |
HIP 23448 |
12.83 |
| 2026-08-01 00:00 |
05:03:09.21 |
+02:10:42.6 |
HIP 23448 |
13.30 |
| 2026-08-01 12:00 |
05:03:12.87 |
+02:10:16.6 |
HIP 23448 |
13.81 |
| 2026-08-02 00:00 |
05:03:16.50 |
+02:09:50.5 |
HIP 23448 |
14.37 |
| 2026-08-02 12:00 |
05:03:20.09 |
+02:09:24.1 |
HIP 23448 |
14.96 |
| 2026-08-03 00:00 |
05:03:23.64 |
+02:08:57.5 |
HIP 23448 |
15.58 |
| 2026-08-03 12:00 |
05:03:27.16 |
+02:08:30.6 |
HIP 23448 |
16.24 |
| 2026-08-04 00:00 |
05:03:30.63 |
+02:08:03.6 |
HIP 23448 |
16.91 |
| 2026-08-04 12:00 |
05:03:34.08 |
+02:07:36.4 |
HIP 23448 |
17.60 |
| 2026-08-05 00:00 |
05:03:37.48 |
+02:07:08.9 |
HIP 23448 |
18.31 |
| 2026-08-05 12:00 |
05:03:40.85 |
+02:06:41.2 |
HIP 23448 |
19.03 |
| 2026-08-06 00:00 |
05:03:44.17 |
+02:06:13.3 |
HIP 23448 |
19.77 |
| 2026-08-06 12:00 |
05:03:47.46 |
+02:05:45.2 |
HIP 23448 |
20.51 |
| 2026-08-07 00:00 |
05:03:50.72 |
+02:05:16.9 |
HIP 23448 |
21.25 |
| 2026-08-07 12:00 |
05:03:53.93 |
+02:04:48.4 |
HIP 23448 |
22.00 |
| 2026-08-08 00:00 |
05:03:57.10 |
+02:04:19.7 |
HIP 23448 |
22.76 |
| 2026-08-08 12:00 |
05:04:00.24 |
+02:03:50.8 |
HIP 23448 |
23.51 |
| 2026-08-09 00:00 |
05:04:03.33 |
+02:03:21.7 |
HIP 23510 |
24.21 |
| 2026-08-09 12:00 |
05:04:06.39 |
+02:02:52.3 |
HIP 23510 |
24.15 |
| 2026-08-10 00:00 |
05:04:09.40 |
+02:02:22.8 |
HIP 23510 |
24.12 |
| 2026-08-10 12:00 |
05:04:12.38 |
+02:01:53.1 |
HIP 23510 |
24.11 |
| 2026-08-11 00:00 |
05:04:15.31 |
+02:01:23.2 |
HIP 23510 |
24.13 |
| 2026-08-11 12:00 |
05:04:18.21 |
+02:00:53.0 |
HIP 23510 |
24.17 |
| 2026-08-12 00:00 |
05:04:21.06 |
+02:00:22.7 |
HIP 23510 |
24.24 |
| 2026-08-12 12:00 |
05:04:23.87 |
+01:59:52.2 |
HIP 23714 |
24.30 |
| 2026-08-13 00:00 |
05:04:26.64 |
+01:59:21.5 |
HIP 23714 |
23.47 |
| 2026-08-13 12:00 |
05:04:29.37 |
+01:58:50.6 |
HIP 23714 |
22.65 |
| 2026-08-14 00:00 |
05:04:32.05 |
+01:58:19.5 |
HIP 23714 |
21.85 |
| 2026-08-14 12:00 |
05:04:34.69 |
+01:57:48.2 |
HIP 23714 |
21.05 |
| 2026-08-15 00:00 |
05:04:37.29 |
+01:57:16.8 |
HIP 23714 |
20.27 |
| 2026-08-15 12:00 |
05:04:39.85 |
+01:56:45.1 |
HIP 23714 |
19.51 |
| 2026-08-16 00:00 |
05:04:42.37 |
+01:56:13.3 |
HIP 23714 |
18.75 |
| 2026-08-16 12:00 |
05:04:44.84 |
+01:55:41.3 |
HIP 23714 |
18.02 |
| 2026-08-17 00:00 |
05:04:47.27 |
+01:55:09.1 |
HIP 23714 |
17.30 |
| 2026-08-17 12:00 |
05:04:49.66 |
+01:54:36.7 |
HIP 23714 |
16.60 |
| 2026-08-18 00:00 |
05:04:52.00 |
+01:54:04.2 |
HIP 23714 |
15.92 |
| 2026-08-18 12:00 |
05:04:54.30 |
+01:53:31.5 |
HIP 23714 |
15.26 |
| 2026-08-19 00:00 |
05:04:56.55 |
+01:52:58.6 |
HIP 23714 |
14.62 |