メタデータ
| 項目 |
値 |
| Designation |
P/2021 Q5 (ATLAS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-08-30T10:00:46.546560Z |
| Orbit solution date (soln_date, UTC) |
2025-01-14T17:42:18Z |
| Obs used |
274 |
| NEO |
Yes |
| M1 |
15.800 |
| K1 |
4.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2021-08-29T14:33:45.619200Z |
| Discovery magnitude (MPC) |
17.59 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) |
2021-09-20.0000000 |
| e |
0.62395172 |
| q (au) |
1.234397 |
| a (au) |
3.282550 |
| i (deg) |
10.733839 |
| Ω (om, deg) |
239.770616 |
| ω (w, deg) |
180.879852 |
| M (ma, deg) |
3.411076 |
等級
散乱 + 全体線形
$$
M_a = (14.774 + 2.320\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
14.774 |
| n |
2.320 |
| gf |
0.999 |
| gb |
-0.998 |
| 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
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) |
| 2026-03-26 00:00 |
19:11:33.04 |
-16:28:00.0 |
HIP 94345 |
9.06 |
| 2026-03-26 12:00 |
19:11:49.94 |
-16:26:29.8 |
HIP 94345 |
4.79 |
| 2026-03-27 00:00 |
19:12:06.66 |
-16:24:59.5 |
HIP 94345 |
1.11 |
| 2026-03-27 12:00 |
19:12:23.22 |
-16:23:29.0 |
HIP 94345 |
3.99 |
| 2026-03-28 00:00 |
19:12:39.61 |
-16:21:58.4 |
HIP 94345 |
8.14 |
| 2026-03-28 12:00 |
19:12:55.83 |
-16:20:27.7 |
HIP 94345 |
12.29 |
| 2026-03-29 00:00 |
19:13:11.88 |
-16:18:56.8 |
HIP 94345 |
16.42 |
| 2026-03-29 12:00 |
19:13:27.75 |
-16:17:25.9 |
HIP 94345 |
20.51 |
| 2026-03-30 00:00 |
19:13:43.45 |
-16:15:54.8 |
HIP 94345 |
24.57 |
| 2026-03-30 12:00 |
19:13:58.97 |
-16:14:23.6 |
HIP 94635 |
22.56 |
| 2026-03-31 00:00 |
19:14:14.32 |
-16:12:52.3 |
HIP 94635 |
18.58 |
| 2026-03-31 12:00 |
19:14:29.49 |
-16:11:21.0 |
HIP 94635 |
14.63 |
| 2026-04-01 00:00 |
19:14:44.48 |
-16:09:49.5 |
HIP 94635 |
10.72 |
| 2026-04-01 12:00 |
19:14:59.29 |
-16:08:17.9 |
HIP 94635 |
6.86 |
| 2026-04-02 00:00 |
19:15:13.92 |
-16:06:46.3 |
HIP 94635 |
3.04 |
| 2026-04-02 12:00 |
19:15:28.37 |
-16:05:14.6 |
HIP 94635 |
0.89 |
| 2026-04-03 00:00 |
19:15:42.64 |
-16:03:42.8 |
HIP 94635 |
4.55 |
| 2026-04-03 12:00 |
19:15:56.72 |
-16:02:11.0 |
HIP 94635 |
8.26 |
| 2026-04-04 00:00 |
19:16:10.61 |
-16:00:39.1 |
HIP 94635 |
11.93 |
| 2026-04-04 12:00 |
19:16:24.31 |
-15:59:07.1 |
HIP 94803 |
15.25 |
| 2026-04-05 00:00 |
19:16:37.83 |
-15:57:35.1 |
HIP 94803 |
12.99 |
| 2026-04-05 12:00 |
19:16:51.16 |
-15:56:03.0 |
HIP 94803 |
11.47 |
| 2026-04-06 00:00 |
19:17:04.29 |
-15:54:30.9 |
HIP 94823 |
9.26 |
| 2026-04-06 12:00 |
19:17:17.23 |
-15:52:58.8 |
HIP 94823 |
7.43 |
| 2026-04-07 00:00 |
19:17:29.98 |
-15:51:26.6 |
HIP 94823 |
7.00 |
| 2026-04-07 12:00 |
19:17:42.53 |
-15:49:54.4 |
HIP 94823 |
8.14 |
| 2026-04-08 00:00 |
19:17:54.89 |
-15:48:22.2 |
HIP 94855 |
9.22 |
| 2026-04-08 12:00 |
19:18:07.04 |
-15:46:50.0 |
HIP 94855 |
10.40 |
| 2026-04-09 00:00 |
19:18:19.00 |
-15:45:17.8 |
HIP 94855 |
12.36 |
| 2026-04-09 12:00 |
19:18:30.76 |
-15:43:45.6 |
HIP 94929 |
13.59 |
| 2026-04-10 00:00 |
19:18:42.31 |
-15:42:13.3 |
HIP 94929 |
10.95 |
| 2026-04-10 12:00 |
19:18:53.66 |
-15:40:41.1 |
HIP 94929 |
8.67 |
| 2026-04-11 00:00 |
19:19:04.80 |
-15:39:09.0 |
HIP 94929 |
7.09 |
| 2026-04-11 12:00 |
19:19:15.74 |
-15:37:36.8 |
HIP 94929 |
6.63 |
| 2026-04-12 00:00 |
19:19:26.47 |
-15:36:04.7 |
HIP 94929 |
7.45 |
| 2026-04-12 12:00 |
19:19:36.99 |
-15:34:32.6 |
HIP 94929 |
9.19 |
| 2026-04-13 00:00 |
19:19:47.29 |
-15:33:00.5 |
HIP 94929 |
11.39 |
| 2026-04-13 12:00 |
19:19:57.39 |
-15:31:28.6 |
HIP 94929 |
13.80 |
| 2026-04-14 00:00 |
19:20:07.27 |
-15:29:56.6 |
HIP 94929 |
16.32 |
| 2026-04-14 12:00 |
19:20:16.93 |
-15:28:24.7 |
HIP 94929 |
18.87 |
| 2026-04-15 00:00 |
19:20:26.38 |
-15:26:52.9 |
HIP 95175 |
19.90 |
| 2026-04-15 12:00 |
19:20:35.61 |
-15:25:21.2 |
HIP 95175 |
18.52 |
| 2026-04-16 00:00 |
19:20:44.63 |
-15:23:49.6 |
HIP 95175 |
17.49 |