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) |
| 2026-05-12 00:00 |
04:48:19.51 |
+30:05:17.2 |
HIP 22410 |
18.55 |
| 2026-05-12 12:00 |
04:48:50.62 |
+30:05:38.0 |
HIP 22410 |
14.28 |
| 2026-05-13 00:00 |
04:49:21.77 |
+30:05:58.7 |
HIP 22410 |
12.42 |
| 2026-05-13 12:00 |
04:49:52.95 |
+30:06:19.4 |
HIP 22410 |
13.99 |
| 2026-05-14 00:00 |
04:50:24.16 |
+30:06:40.1 |
HIP 22410 |
18.11 |
| 2026-05-14 12:00 |
04:50:55.40 |
+30:07:00.7 |
HIP 22571 |
18.49 |
| 2026-05-15 00:00 |
04:51:26.66 |
+30:07:21.3 |
HIP 22571 |
17.45 |
| 2026-05-15 12:00 |
04:51:57.95 |
+30:07:41.8 |
HIP 22677 |
17.82 |
| 2026-05-16 00:00 |
04:52:29.26 |
+30:08:02.3 |
HIP 22677 |
15.38 |
| 2026-05-16 12:00 |
04:53:00.60 |
+30:08:22.8 |
HIP 22677 |
15.72 |
| 2026-05-17 00:00 |
04:53:31.96 |
+30:08:43.2 |
HIP 22677 |
18.70 |
| 2026-05-17 12:00 |
04:54:03.34 |
+30:09:03.5 |
HIP 22677 |
23.33 |
| 2026-05-18 00:00 |
04:54:34.74 |
+30:09:23.8 |
HIP 22964 |
26.56 |
| 2026-05-18 12:00 |
04:55:06.17 |
+30:09:44.0 |
HIP 22964 |
20.54 |
| 2026-05-19 00:00 |
04:55:37.61 |
+30:10:04.2 |
HIP 22964 |
15.21 |
| 2026-05-19 12:00 |
04:56:09.08 |
+30:10:24.3 |
HIP 22964 |
11.54 |
| 2026-05-20 00:00 |
04:56:40.56 |
+30:10:44.3 |
HIP 22964 |
11.32 |
| 2026-05-20 12:00 |
04:57:12.06 |
+30:11:04.3 |
HIP 22964 |
14.70 |
| 2026-05-21 00:00 |
04:57:43.58 |
+30:11:24.2 |
HIP 22964 |
19.93 |
| 2026-05-21 12:00 |
04:58:15.11 |
+30:11:44.0 |
HIP 23143 |
22.16 |
| 2026-05-22 00:00 |
04:58:46.65 |
+30:12:03.7 |
HIP 23143 |
21.44 |
| 2026-05-22 12:00 |
04:59:18.21 |
+30:12:23.3 |
HIP 23143 |
22.84 |
| 2026-05-23 00:00 |
04:59:49.79 |
+30:12:42.9 |
HIP 23143 |
26.02 |
| 2026-05-23 12:00 |
05:00:21.37 |
+30:13:02.3 |
HIP 23438 |
28.47 |
| 2026-05-24 00:00 |
05:00:52.97 |
+30:13:21.7 |
HIP 23438 |
22.85 |
| 2026-05-24 12:00 |
05:01:24.58 |
+30:13:41.0 |
HIP 23438 |
18.09 |
| 2026-05-25 00:00 |
05:01:56.20 |
+30:14:00.1 |
HIP 23438 |
15.03 |
| 2026-05-25 12:00 |
05:02:27.83 |
+30:14:19.2 |
HIP 23438 |
14.78 |
| 2026-05-26 00:00 |
05:02:59.46 |
+30:14:38.2 |
HIP 23438 |
17.46 |
| 2026-05-26 12:00 |
05:03:31.11 |
+30:14:57.1 |
HIP 23608 |
15.78 |
| 2026-05-27 00:00 |
05:04:02.76 |
+30:15:15.9 |
HIP 23608 |
10.20 |
| 2026-05-27 12:00 |
05:04:34.42 |
+30:15:34.5 |
HIP 23608 |
7.25 |
| 2026-05-28 00:00 |
05:05:06.09 |
+30:15:53.1 |
HIP 23608 |
9.73 |
| 2026-05-28 12:00 |
05:05:37.76 |
+30:16:11.6 |
HIP 23608 |
15.18 |
| 2026-05-29 00:00 |
05:06:09.44 |
+30:16:29.9 |
HIP 23608 |
21.45 |
| 2026-05-29 12:00 |
05:06:41.12 |
+30:16:48.1 |
HIP 23873 |
16.47 |
| 2026-05-30 00:00 |
05:07:12.81 |
+30:17:06.3 |
HIP 23873 |
10.57 |
| 2026-05-30 12:00 |
05:07:44.50 |
+30:17:24.3 |
HIP 23873 |
6.77 |
| 2026-05-31 00:00 |
05:08:16.19 |
+30:17:42.1 |
HIP 23873 |
8.59 |
| 2026-05-31 12:00 |
05:08:47.89 |
+30:18:00.0 |
HIP 23873 |
13.98 |
| 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 |