メタデータ
| 項目 |
値 |
| Designation |
C/2021 Q3 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-01-26T01:52:57.941760Z |
| Orbit solution date (soln_date, UTC) |
2023-03-20T19:42:36Z |
| Obs used |
180 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
11.750 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2021-08-26T07:07:01.228800Z |
| Discovery magnitude (MPC) |
19.02 o |
| Discovery observatory (MPC) |
T05 · ATLAS-HKO, Haleakala |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2022-01-10.0000000 |
| e |
0.93033551 |
| q (au) |
5.204636 |
| a (au) |
74.710023 |
| i (deg) |
77.777282 |
| Ω (om, deg) |
307.900611 |
| ω (w, deg) |
114.090847 |
| M (ma, deg) |
359.975460 |
等級
散乱 + 全体線形
$$
M_a = (3.505 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
3.505 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
08:35:00.33 |
-12:34:59.3 |
HIP 42050 |
18.00 |
| 2026-07-29 12:00 |
08:35:09.32 |
-12:36:07.5 |
HIP 42050 |
20.27 |
| 2026-07-30 00:00 |
08:35:18.30 |
-12:37:16.2 |
HIP 42050 |
22.59 |
| 2026-07-30 12:00 |
08:35:27.28 |
-12:38:25.4 |
HIP 42050 |
24.94 |
| 2026-07-31 00:00 |
08:35:36.26 |
-12:39:35.2 |
HIP 42050 |
27.32 |
| 2026-07-31 12:00 |
08:35:45.23 |
-12:40:45.6 |
HIP 42309 |
27.07 |
| 2026-08-01 00:00 |
08:35:54.20 |
-12:41:56.5 |
HIP 42309 |
25.23 |
| 2026-08-01 12:00 |
08:36:03.16 |
-12:43:07.9 |
HIP 42309 |
23.51 |
| 2026-08-02 00:00 |
08:36:12.11 |
-12:44:19.8 |
HIP 42309 |
21.94 |
| 2026-08-02 12:00 |
08:36:21.06 |
-12:45:32.3 |
HIP 42309 |
20.56 |
| 2026-08-03 00:00 |
08:36:30.01 |
-12:46:45.4 |
HIP 42309 |
19.41 |
| 2026-08-03 12:00 |
08:36:38.94 |
-12:47:58.9 |
HIP 42309 |
18.54 |
| 2026-08-04 00:00 |
08:36:47.87 |
-12:49:13.1 |
HIP 42336 |
17.32 |
| 2026-08-04 12:00 |
08:36:56.79 |
-12:50:27.7 |
HIP 42336 |
15.94 |
| 2026-08-05 00:00 |
08:37:05.70 |
-12:51:42.9 |
HIP 42336 |
14.87 |
| 2026-08-05 12:00 |
08:37:14.60 |
-12:52:58.6 |
HIP 42336 |
14.17 |
| 2026-08-06 00:00 |
08:37:23.49 |
-12:54:14.8 |
HIP 42336 |
13.91 |
| 2026-08-06 12:00 |
08:37:32.37 |
-12:55:31.5 |
HIP 42336 |
14.10 |
| 2026-08-07 00:00 |
08:37:41.25 |
-12:56:48.8 |
HIP 42336 |
14.74 |
| 2026-08-07 12:00 |
08:37:50.11 |
-12:58:06.6 |
HIP 42336 |
15.77 |
| 2026-08-08 00:00 |
08:37:58.95 |
-12:59:25.0 |
HIP 42336 |
17.12 |
| 2026-08-08 12:00 |
08:38:07.79 |
-13:00:43.8 |
HIP 42401 |
17.29 |
| 2026-08-09 00:00 |
08:38:16.62 |
-13:02:03.2 |
HIP 42401 |
15.07 |
| 2026-08-09 12:00 |
08:38:25.43 |
-13:03:23.1 |
HIP 42401 |
12.96 |
| 2026-08-10 00:00 |
08:38:34.22 |
-13:04:43.5 |
HIP 42401 |
11.02 |
| 2026-08-10 12:00 |
08:38:43.00 |
-13:06:04.4 |
HIP 42401 |
9.35 |
| 2026-08-11 00:00 |
08:38:51.77 |
-13:07:25.8 |
HIP 42401 |
8.13 |
| 2026-08-11 12:00 |
08:39:00.52 |
-13:08:47.8 |
HIP 42401 |
7.58 |
| 2026-08-12 00:00 |
08:39:09.26 |
-13:10:10.2 |
HIP 42401 |
7.84 |
| 2026-08-12 12:00 |
08:39:17.98 |
-13:11:33.2 |
HIP 42401 |
8.84 |
| 2026-08-13 00:00 |
08:39:26.68 |
-13:12:56.6 |
HIP 42401 |
10.37 |
| 2026-08-13 12:00 |
08:39:35.37 |
-13:14:20.6 |
HIP 42401 |
12.23 |
| 2026-08-14 00:00 |
08:39:44.03 |
-13:15:45.1 |
HIP 42401 |
14.30 |
| 2026-08-14 12:00 |
08:39:52.68 |
-13:17:10.0 |
HIP 42401 |
16.49 |
| 2026-08-15 00:00 |
08:40:01.31 |
-13:18:35.5 |
HIP 42531 |
15.75 |
| 2026-08-15 12:00 |
08:40:09.92 |
-13:20:01.4 |
HIP 42531 |
14.03 |
| 2026-08-16 00:00 |
08:40:18.51 |
-13:21:27.9 |
HIP 42531 |
12.57 |
| 2026-08-16 12:00 |
08:40:27.08 |
-13:22:54.8 |
HIP 42531 |
11.49 |
| 2026-08-17 00:00 |
08:40:35.62 |
-13:24:22.2 |
HIP 42531 |
10.89 |
| 2026-08-17 12:00 |
08:40:44.15 |
-13:25:50.1 |
HIP 42531 |
10.86 |
| 2026-08-18 00:00 |
08:40:52.65 |
-13:27:18.4 |
HIP 42531 |
11.40 |
| 2026-08-18 12:00 |
08:41:01.13 |
-13:28:47.2 |
HIP 42531 |
12.43 |
| 2026-08-19 00:00 |
08:41:09.59 |
-13:30:16.5 |
HIP 42531 |
13.85 |