メタデータ
| 項目 |
値 |
| Designation |
490P/ATLAS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2019-06-22T16:00:54.581760Z |
| Orbit solution date (soln_date, UTC) |
2024-12-03T17:12:47Z |
| Obs used |
368 |
| NEO |
Yes |
| M1 |
20.500 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-06-29T13:56:52.051200Z |
| Discovery magnitude (MPC) |
18.36 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) |
2019-12-01.0000000 |
| e |
0.64849913 |
| q (au) |
1.063456 |
| a (au) |
3.025473 |
| i (deg) |
12.281885 |
| Ω (om, deg) |
307.601988 |
| ω (w, deg) |
332.525414 |
| M (ma, deg) |
30.215976 |
等級
散乱 + 全体線形
$$
M_a = (19.669 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
19.669 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.735 |
| k |
0.975 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
05:09:19.59 |
+30:18:17.5 |
HIP 24065 |
20.06 |
| 2026-06-01 12:00 |
05:09:51.28 |
+30:18:35.1 |
HIP 24065 |
16.68 |
| 2026-06-02 00:00 |
05:10:22.98 |
+30:18:52.5 |
HIP 24065 |
15.74 |
| 2026-06-02 12:00 |
05:10:54.68 |
+30:19:09.7 |
HIP 24065 |
17.62 |
| 2026-06-03 00:00 |
05:11:26.38 |
+30:19:26.9 |
HIP 24258 |
14.46 |
| 2026-06-03 12:00 |
05:11:58.08 |
+30:19:43.9 |
HIP 24258 |
9.05 |
| 2026-06-04 00:00 |
05:12:29.77 |
+30:20:00.8 |
HIP 24258 |
6.98 |
| 2026-06-04 12:00 |
05:13:01.46 |
+30:20:17.5 |
HIP 24258 |
10.45 |
| 2026-06-05 00:00 |
05:13:33.15 |
+30:20:34.1 |
HIP 24413 |
9.54 |
| 2026-06-05 12:00 |
05:14:04.84 |
+30:20:50.6 |
HIP 24413 |
3.77 |
| 2026-06-06 00:00 |
05:14:36.52 |
+30:21:07.0 |
HIP 24413 |
5.56 |
| 2026-06-06 12:00 |
05:15:08.19 |
+30:21:23.2 |
HIP 24497 |
2.86 |
| 2026-06-07 00:00 |
05:15:39.87 |
+30:21:39.3 |
HIP 24501 |
4.05 |
| 2026-06-07 12:00 |
05:16:11.53 |
+30:21:55.2 |
HIP 24540 |
8.78 |
| 2026-06-08 00:00 |
05:16:43.19 |
+30:22:11.0 |
HIP 24540 |
13.10 |
| 2026-06-08 12:00 |
05:17:14.84 |
+30:22:26.7 |
HIP 24755 |
15.93 |
| 2026-06-09 00:00 |
05:17:46.48 |
+30:22:42.2 |
HIP 24755 |
9.10 |
| 2026-06-09 12:00 |
05:18:18.12 |
+30:22:57.6 |
HIP 24755 |
2.30 |
| 2026-06-10 00:00 |
05:18:49.74 |
+30:23:12.8 |
HIP 24755 |
4.58 |
| 2026-06-10 12:00 |
05:19:21.36 |
+30:23:27.9 |
HIP 24878 |
11.12 |
| 2026-06-11 00:00 |
05:19:52.96 |
+30:23:42.9 |
HIP 24878 |
7.12 |
| 2026-06-11 12:00 |
05:20:24.56 |
+30:23:57.7 |
HIP 24878 |
8.41 |
| 2026-06-12 00:00 |
05:20:56.14 |
+30:24:12.3 |
HIP 24878 |
13.55 |
| 2026-06-12 12:00 |
05:21:27.71 |
+30:24:26.8 |
HIP 24878 |
19.72 |
| 2026-06-13 00:00 |
05:21:59.26 |
+30:24:41.2 |
HIP 24878 |
26.21 |
| 2026-06-13 12:00 |
05:22:30.80 |
+30:24:55.4 |
HIP 25237 |
20.41 |
| 2026-06-14 00:00 |
05:23:02.32 |
+30:25:09.5 |
HIP 25237 |
15.22 |
| 2026-06-14 12:00 |
05:23:33.83 |
+30:25:23.4 |
HIP 25237 |
11.80 |
| 2026-06-15 00:00 |
05:24:05.32 |
+30:25:37.2 |
HIP 25237 |
11.81 |
| 2026-06-15 12:00 |
05:24:36.80 |
+30:25:50.8 |
HIP 25237 |
15.24 |
| 2026-06-16 00:00 |
05:25:08.25 |
+30:26:04.3 |
HIP 25418 |
17.84 |
| 2026-06-16 12:00 |
05:25:39.68 |
+30:26:17.6 |
HIP 25418 |
13.54 |
| 2026-06-17 00:00 |
05:26:11.10 |
+30:26:30.8 |
HIP 25418 |
11.84 |
| 2026-06-17 12:00 |
05:26:42.49 |
+30:26:43.8 |
HIP 25418 |
13.74 |
| 2026-06-18 00:00 |
05:27:13.86 |
+30:26:56.6 |
HIP 25492 |
14.48 |
| 2026-06-18 12:00 |
05:27:45.21 |
+30:27:09.3 |
HIP 25492 |
16.67 |
| 2026-06-19 00:00 |
05:28:16.53 |
+30:27:21.9 |
HIP 25492 |
20.91 |
| 2026-06-19 12:00 |
05:28:47.83 |
+30:27:34.3 |
HIP 25789 |
21.15 |
| 2026-06-20 00:00 |
05:29:19.11 |
+30:27:46.6 |
HIP 25789 |
14.48 |
| 2026-06-20 12:00 |
05:29:50.35 |
+30:27:58.7 |
HIP 25789 |
7.93 |
| 2026-06-21 00:00 |
05:30:21.58 |
+30:28:10.6 |
HIP 25789 |
2.62 |
| 2026-06-21 12:00 |
05:30:52.77 |
+30:28:22.4 |
HIP 25789 |
6.44 |
| 2026-06-22 00:00 |
05:31:23.94 |
+30:28:34.0 |
HIP 25789 |
12.90 |