メタデータ
| 項目 |
値 |
| Designation |
C/2021 Y1 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-04-30T16:42:49.288320Z |
| Orbit solution date (soln_date, UTC) |
2024-04-13T16:42:29Z |
| Obs used |
1857 |
| NEO |
- |
| M1 |
12.000 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-12-26T06:50:24.691200Z |
| Discovery magnitude (MPC) |
18.99 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) |
2022-10-17.0000000 |
| e |
1.00083371 |
| q (au) |
2.032510 |
| a (au) |
-2437.901109 |
| i (deg) |
77.187480 |
| Ω (om, deg) |
244.769593 |
| ω (w, deg) |
245.810207 |
| M (ma, deg) |
-0.001602 |
等級
散乱 + 全体線形
$$
M_a = (11.482 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
11.482 |
| n |
2.000 |
| gf |
0.833 |
| gb |
-0.807 |
| k |
0.997 |
| δ90 |
1.000 |
| 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
ファインディングチャート
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
16:14:38.65 |
-06:40:47.1 |
HIP 79545 |
17.66 |
| 2026-07-29 12:00 |
16:14:34.31 |
-06:40:41.7 |
HIP 79545 |
17.07 |
| 2026-07-30 00:00 |
16:14:30.06 |
-06:40:36.6 |
HIP 79545 |
16.55 |
| 2026-07-30 12:00 |
16:14:25.90 |
-06:40:31.9 |
HIP 79545 |
16.08 |
| 2026-07-31 00:00 |
16:14:21.83 |
-06:40:27.6 |
HIP 79545 |
15.67 |
| 2026-07-31 12:00 |
16:14:17.86 |
-06:40:23.7 |
HIP 79545 |
15.32 |
| 2026-08-01 00:00 |
16:14:13.98 |
-06:40:20.2 |
HIP 79545 |
15.02 |
| 2026-08-01 12:00 |
16:14:10.19 |
-06:40:17.0 |
HIP 79545 |
14.79 |
| 2026-08-02 00:00 |
16:14:06.49 |
-06:40:14.3 |
HIP 79545 |
14.61 |
| 2026-08-02 12:00 |
16:14:02.89 |
-06:40:12.0 |
HIP 79545 |
14.48 |
| 2026-08-03 00:00 |
16:13:59.37 |
-06:40:10.0 |
HIP 79545 |
14.41 |
| 2026-08-03 12:00 |
16:13:55.96 |
-06:40:08.4 |
HIP 79545 |
14.38 |
| 2026-08-04 00:00 |
16:13:52.63 |
-06:40:07.2 |
HIP 79545 |
14.39 |
| 2026-08-04 12:00 |
16:13:49.40 |
-06:40:06.4 |
HIP 79545 |
14.45 |
| 2026-08-05 00:00 |
16:13:46.26 |
-06:40:05.9 |
HIP 79545 |
14.54 |
| 2026-08-05 12:00 |
16:13:43.22 |
-06:40:05.8 |
HIP 79545 |
14.65 |
| 2026-08-06 00:00 |
16:13:40.26 |
-06:40:06.1 |
HIP 79545 |
14.80 |
| 2026-08-06 12:00 |
16:13:37.41 |
-06:40:06.7 |
HIP 79545 |
14.97 |
| 2026-08-07 00:00 |
16:13:34.64 |
-06:40:07.7 |
HIP 79545 |
15.15 |
| 2026-08-07 12:00 |
16:13:31.97 |
-06:40:09.1 |
HIP 79447 |
15.02 |
| 2026-08-08 00:00 |
16:13:29.39 |
-06:40:10.8 |
HIP 79447 |
14.54 |
| 2026-08-08 12:00 |
16:13:26.91 |
-06:40:12.8 |
HIP 79447 |
14.08 |
| 2026-08-09 00:00 |
16:13:24.52 |
-06:40:15.2 |
HIP 79447 |
13.65 |
| 2026-08-09 12:00 |
16:13:22.23 |
-06:40:18.0 |
HIP 79447 |
13.24 |
| 2026-08-10 00:00 |
16:13:20.02 |
-06:40:21.1 |
HIP 79447 |
12.86 |
| 2026-08-10 12:00 |
16:13:17.92 |
-06:40:24.5 |
HIP 79447 |
12.49 |
| 2026-08-11 00:00 |
16:13:15.90 |
-06:40:28.3 |
HIP 79447 |
12.15 |
| 2026-08-11 12:00 |
16:13:13.98 |
-06:40:32.4 |
HIP 79447 |
11.82 |
| 2026-08-12 00:00 |
16:13:12.16 |
-06:40:36.9 |
HIP 79447 |
11.52 |
| 2026-08-12 12:00 |
16:13:10.43 |
-06:40:41.6 |
HIP 79447 |
11.23 |
| 2026-08-13 00:00 |
16:13:08.79 |
-06:40:46.7 |
HIP 79447 |
10.96 |
| 2026-08-13 12:00 |
16:13:07.25 |
-06:40:52.2 |
HIP 79447 |
10.70 |
| 2026-08-14 00:00 |
16:13:05.80 |
-06:40:57.9 |
HIP 79447 |
10.46 |
| 2026-08-14 12:00 |
16:13:04.45 |
-06:41:03.9 |
HIP 79447 |
10.23 |
| 2026-08-15 00:00 |
16:13:03.18 |
-06:41:10.3 |
HIP 79447 |
10.01 |
| 2026-08-15 12:00 |
16:13:02.02 |
-06:41:16.9 |
HIP 79447 |
9.80 |
| 2026-08-16 00:00 |
16:13:00.94 |
-06:41:23.9 |
HIP 79447 |
9.59 |
| 2026-08-16 12:00 |
16:12:59.96 |
-06:41:31.1 |
HIP 79447 |
9.40 |
| 2026-08-17 00:00 |
16:12:59.07 |
-06:41:38.7 |
HIP 79447 |
9.21 |
| 2026-08-17 12:00 |
16:12:58.28 |
-06:41:46.5 |
HIP 79447 |
9.03 |
| 2026-08-18 00:00 |
16:12:57.58 |
-06:41:54.6 |
HIP 79447 |
8.85 |
| 2026-08-18 12:00 |
16:12:56.97 |
-06:42:03.0 |
HIP 79447 |
8.67 |
| 2026-08-19 00:00 |
16:12:56.45 |
-06:42:11.7 |
HIP 79447 |
8.50 |