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) |
| 2026-05-12 00:00 |
14:34:11.07 |
-67:26:17.0 |
HIP 71343 |
6.98 |
| 2026-05-12 12:00 |
14:33:48.24 |
-67:25:22.5 |
HIP 71343 |
9.17 |
| 2026-05-13 00:00 |
14:33:25.48 |
-67:24:26.8 |
HIP 71343 |
11.43 |
| 2026-05-13 12:00 |
14:33:02.80 |
-67:23:29.9 |
HIP 71159 |
12.30 |
| 2026-05-14 00:00 |
14:32:40.22 |
-67:22:31.7 |
HIP 71159 |
11.75 |
| 2026-05-14 12:00 |
14:32:17.72 |
-67:21:32.3 |
HIP 71159 |
11.65 |
| 2026-05-15 00:00 |
14:31:55.32 |
-67:20:31.7 |
HIP 71159 |
12.01 |
| 2026-05-15 12:00 |
14:31:33.01 |
-67:19:29.9 |
HIP 71159 |
12.80 |
| 2026-05-16 00:00 |
14:31:10.80 |
-67:18:26.9 |
HIP 71159 |
13.94 |
| 2026-05-16 12:00 |
14:30:48.69 |
-67:17:22.8 |
HIP 71159 |
15.36 |
| 2026-05-17 00:00 |
14:30:26.68 |
-67:16:17.4 |
HIP 71159 |
16.98 |
| 2026-05-17 12:00 |
14:30:04.79 |
-67:15:10.9 |
HIP 71159 |
18.76 |
| 2026-05-18 00:00 |
14:29:43.00 |
-67:14:03.2 |
HIP 70624 |
19.92 |
| 2026-05-18 12:00 |
14:29:21.33 |
-67:12:54.3 |
HIP 70624 |
18.90 |
| 2026-05-19 00:00 |
14:28:59.77 |
-67:11:44.3 |
HIP 70624 |
18.16 |
| 2026-05-19 12:00 |
14:28:38.33 |
-67:10:33.2 |
HIP 70624 |
17.72 |
| 2026-05-20 00:00 |
14:28:17.02 |
-67:09:21.0 |
HIP 70624 |
17.62 |
| 2026-05-20 12:00 |
14:27:55.83 |
-67:08:07.7 |
HIP 70624 |
17.86 |
| 2026-05-21 00:00 |
14:27:34.76 |
-67:06:53.2 |
HIP 70624 |
18.43 |
| 2026-05-21 12:00 |
14:27:13.82 |
-67:05:37.7 |
HIP 70624 |
19.30 |
| 2026-05-22 00:00 |
14:26:53.02 |
-67:04:21.1 |
HIP 70624 |
20.43 |
| 2026-05-22 12:00 |
14:26:32.35 |
-67:03:03.5 |
HIP 70624 |
21.78 |
| 2026-05-23 00:00 |
14:26:11.82 |
-67:01:44.8 |
HIP 70624 |
23.31 |
| 2026-05-23 12:00 |
14:25:51.42 |
-67:00:25.0 |
HIP 70624 |
24.99 |
| 2026-05-24 00:00 |
14:25:31.16 |
-66:59:04.2 |
HIP 70346 |
23.50 |
| 2026-05-24 12:00 |
14:25:11.05 |
-66:57:42.5 |
HIP 70346 |
21.36 |
| 2026-05-25 00:00 |
14:24:51.08 |
-66:56:19.6 |
HIP 70346 |
19.27 |
| 2026-05-25 12:00 |
14:24:31.26 |
-66:54:55.9 |
HIP 70346 |
17.25 |
| 2026-05-26 00:00 |
14:24:11.59 |
-66:53:31.1 |
HIP 70346 |
15.32 |
| 2026-05-26 12:00 |
14:23:52.07 |
-66:52:05.3 |
HIP 70346 |
13.54 |
| 2026-05-27 00:00 |
14:23:32.70 |
-66:50:38.6 |
HIP 70346 |
11.95 |
| 2026-05-27 12:00 |
14:23:13.49 |
-66:49:10.9 |
HIP 70346 |
10.64 |
| 2026-05-28 00:00 |
14:22:54.43 |
-66:47:42.3 |
HIP 70196 |
8.27 |
| 2026-05-28 12:00 |
14:22:35.53 |
-66:46:12.8 |
HIP 70196 |
5.90 |
| 2026-05-29 00:00 |
14:22:16.79 |
-66:44:42.4 |
HIP 70196 |
3.57 |
| 2026-05-29 12:00 |
14:21:58.21 |
-66:43:11.0 |
HIP 70196 |
1.43 |
| 2026-05-30 00:00 |
14:21:39.80 |
-66:41:38.8 |
HIP 70196 |
1.67 |
| 2026-05-30 12:00 |
14:21:21.55 |
-66:40:05.7 |
HIP 70196 |
3.86 |
| 2026-05-31 00:00 |
14:21:03.46 |
-66:38:31.7 |
HIP 70196 |
6.19 |
| 2026-05-31 12:00 |
14:20:45.55 |
-66:36:56.9 |
HIP 70196 |
8.55 |
| 2026-06-01 00:00 |
14:20:27.80 |
-66:35:21.2 |
HIP 70196 |
10.92 |
| 2026-06-01 12:00 |
14:20:10.23 |
-66:33:44.7 |
HIP 70196 |
13.29 |
| 2026-06-02 00:00 |
14:19:52.82 |
-66:32:07.4 |
HIP 70196 |
15.66 |