メタデータ
| 項目 |
値 |
| Designation |
C/2022 U2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-01-14T05:16:42.461760Z |
| Orbit solution date (soln_date, UTC) |
2023-11-04T19:42:53Z |
| Obs used |
996 |
| NEO |
- |
| M1 |
13.600 |
| K1 |
19.750 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2022-10-25T05:05:57.926400Z |
| Discovery magnitude (MPC) |
19.13 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) |
2023-01-07.0000000 |
| e |
0.98612019 |
| q (au) |
1.328023 |
| a (au) |
95.680211 |
| i (deg) |
48.249781 |
| Ω (om, deg) |
304.475901 |
| ω (w, deg) |
147.908535 |
| M (ma, deg) |
359.992397 |
等級
散乱 + 全体線形
$$
M_a = (13.410 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.410 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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 |
| 2022-10-25 |
2022-11-25 |
+10.6742 |
-2.041 |
| 2022-11-25 |
2023-01-13 |
+45.3999 |
-7.789 |
| 2023-01-14 |
2023-05-19 |
+3.5650 |
-2.032 |
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) |
| 2026-03-26 00:00 |
15:08:13.58 |
-67:13:29.5 |
HIP 74184 |
11.23 |
| 2026-03-26 12:00 |
15:07:57.43 |
-67:14:35.7 |
HIP 74184 |
13.10 |
| 2026-03-27 00:00 |
15:07:41.08 |
-67:15:40.9 |
HIP 74184 |
14.98 |
| 2026-03-27 12:00 |
15:07:24.54 |
-67:16:45.1 |
HIP 74184 |
16.87 |
| 2026-03-28 00:00 |
15:07:07.80 |
-67:17:48.1 |
HIP 74184 |
18.77 |
| 2026-03-28 12:00 |
15:06:50.88 |
-67:18:50.1 |
HIP 74184 |
20.68 |
| 2026-03-29 00:00 |
15:06:33.76 |
-67:19:50.9 |
HIP 73603 |
22.39 |
| 2026-03-29 12:00 |
15:06:16.45 |
-67:20:50.7 |
HIP 73603 |
20.80 |
| 2026-03-30 00:00 |
15:05:58.96 |
-67:21:49.3 |
HIP 73603 |
19.25 |
| 2026-03-30 12:00 |
15:05:41.29 |
-67:22:46.8 |
HIP 73603 |
17.77 |
| 2026-03-31 00:00 |
15:05:23.43 |
-67:23:43.2 |
HIP 73603 |
16.36 |
| 2026-03-31 12:00 |
15:05:05.40 |
-67:24:38.5 |
HIP 73603 |
15.06 |
| 2026-04-01 00:00 |
15:04:47.18 |
-67:25:32.6 |
HIP 73603 |
13.89 |
| 2026-04-01 12:00 |
15:04:28.79 |
-67:26:25.6 |
HIP 73603 |
12.89 |
| 2026-04-02 00:00 |
15:04:10.23 |
-67:27:17.4 |
HIP 73603 |
12.12 |
| 2026-04-02 12:00 |
15:03:51.49 |
-67:28:08.1 |
HIP 73603 |
11.61 |
| 2026-04-03 00:00 |
15:03:32.59 |
-67:28:57.5 |
HIP 73551 |
10.60 |
| 2026-04-03 12:00 |
15:03:13.51 |
-67:29:45.8 |
HIP 73551 |
9.51 |
| 2026-04-04 00:00 |
15:02:54.28 |
-67:30:32.9 |
HIP 73551 |
8.71 |
| 2026-04-04 12:00 |
15:02:34.87 |
-67:31:18.8 |
HIP 73551 |
8.31 |
| 2026-04-05 00:00 |
15:02:15.31 |
-67:32:03.5 |
HIP 73551 |
8.36 |
| 2026-04-05 12:00 |
15:01:55.59 |
-67:32:47.0 |
HIP 73551 |
8.86 |
| 2026-04-06 00:00 |
15:01:35.72 |
-67:33:29.3 |
HIP 73551 |
9.75 |
| 2026-04-06 12:00 |
15:01:15.69 |
-67:34:10.3 |
HIP 73551 |
10.93 |
| 2026-04-07 00:00 |
15:00:55.51 |
-67:34:50.1 |
HIP 73551 |
12.32 |
| 2026-04-07 12:00 |
15:00:35.18 |
-67:35:28.7 |
HIP 73405 |
13.53 |
| 2026-04-08 00:00 |
15:00:14.71 |
-67:36:06.0 |
HIP 73405 |
13.85 |
| 2026-04-08 12:00 |
14:59:54.09 |
-67:36:42.1 |
HIP 73405 |
14.44 |
| 2026-04-09 00:00 |
14:59:33.33 |
-67:37:16.9 |
HIP 73405 |
15.28 |
| 2026-04-09 12:00 |
14:59:12.44 |
-67:37:50.4 |
HIP 73405 |
16.31 |
| 2026-04-10 00:00 |
14:58:51.41 |
-67:38:22.7 |
HIP 73405 |
17.52 |
| 2026-04-10 12:00 |
14:58:30.24 |
-67:38:53.6 |
HIP 73405 |
18.86 |
| 2026-04-11 00:00 |
14:58:08.95 |
-67:39:23.3 |
HIP 73405 |
20.33 |
| 2026-04-11 12:00 |
14:57:47.53 |
-67:39:51.7 |
HIP 72942 |
18.93 |
| 2026-04-12 00:00 |
14:57:25.98 |
-67:40:18.8 |
HIP 72942 |
16.92 |
| 2026-04-12 12:00 |
14:57:04.31 |
-67:40:44.6 |
HIP 72942 |
14.92 |
| 2026-04-13 00:00 |
14:56:42.53 |
-67:41:09.1 |
HIP 72942 |
12.94 |
| 2026-04-13 12:00 |
14:56:20.63 |
-67:41:32.2 |
HIP 72942 |
10.99 |
| 2026-04-14 00:00 |
14:55:58.62 |
-67:41:54.0 |
HIP 72942 |
9.10 |
| 2026-04-14 12:00 |
14:55:36.50 |
-67:42:14.6 |
HIP 72942 |
7.32 |
| 2026-04-15 00:00 |
14:55:14.27 |
-67:42:33.7 |
HIP 72942 |
5.76 |
| 2026-04-15 12:00 |
14:54:51.94 |
-67:42:51.6 |
HIP 72942 |
4.66 |
| 2026-04-16 00:00 |
14:54:29.51 |
-67:43:08.1 |
HIP 72942 |
4.37 |