C/2021 S1 (ATLAS)
メタデータ
| 項目 |
値 |
| Designation |
C/2021 S1 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-02-28T22:41:40.444800Z |
| Orbit solution date (soln_date, UTC) |
2024-06-06T23:12:23Z |
| Obs used |
476 |
| NEO |
- |
| M1 |
6.700 |
| K1 |
10.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2021-09-27T13:41:00.096000Z |
| Discovery magnitude (MPC) |
17.82 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) |
2022-03-23.0000000 |
| e |
1.00095649 |
| q (au) |
6.119212 |
| a (au) |
-6397.577104 |
| i (deg) |
52.088959 |
| Ω (om, deg) |
299.873636 |
| ω (w, deg) |
148.188635 |
| M (ma, deg) |
0.000042 |
等級
散乱 + 全体線形
$$
M_a = (5.453 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
5.453 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.717 |
| k |
0.800 |
| 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) |
| 2026-02-03 00:00 |
09:43:21.65 |
-31:11:05.1 |
HIP 47678 |
23.05 |
| 2026-02-03 12:00 |
09:43:11.08 |
-31:11:30.4 |
HIP 47678 |
22.67 |
| 2026-02-04 00:00 |
09:43:00.49 |
-31:11:54.6 |
HIP 47678 |
22.53 |
| 2026-02-04 12:00 |
09:42:49.88 |
-31:12:17.6 |
HIP 47678 |
22.65 |
| 2026-02-05 00:00 |
09:42:39.25 |
-31:12:39.5 |
HIP 47678 |
23.01 |
| 2026-02-05 12:00 |
09:42:28.61 |
-31:13:00.2 |
HIP 47678 |
23.61 |
| 2026-02-06 00:00 |
09:42:17.95 |
-31:13:19.8 |
HIP 47678 |
24.44 |
| 2026-02-06 12:00 |
09:42:07.27 |
-31:13:38.3 |
HIP 47678 |
25.46 |
| 2026-02-07 00:00 |
09:41:56.59 |
-31:13:55.6 |
HIP 47678 |
26.66 |
| 2026-02-07 12:00 |
09:41:45.89 |
-31:14:11.7 |
HIP 47451 |
26.83 |
| 2026-02-08 00:00 |
09:41:35.18 |
-31:14:26.8 |
HIP 47451 |
25.44 |
| 2026-02-08 12:00 |
09:41:24.46 |
-31:14:40.7 |
HIP 47451 |
24.18 |
| 2026-02-09 00:00 |
09:41:13.73 |
-31:14:53.4 |
HIP 47451 |
23.06 |
| 2026-02-09 12:00 |
09:41:03.00 |
-31:15:05.0 |
HIP 47451 |
22.10 |
| 2026-02-10 00:00 |
09:40:52.26 |
-31:15:15.5 |
HIP 47451 |
21.34 |
| 2026-02-10 12:00 |
09:40:41.52 |
-31:15:24.9 |
HIP 47451 |
20.79 |
| 2026-02-11 00:00 |
09:40:30.77 |
-31:15:33.1 |
HIP 47451 |
20.46 |
| 2026-02-11 12:00 |
09:40:20.02 |
-31:15:40.2 |
HIP 47451 |
20.38 |
| 2026-02-12 00:00 |
09:40:09.27 |
-31:15:46.2 |
HIP 47451 |
20.53 |
| 2026-02-12 12:00 |
09:39:58.53 |
-31:15:51.0 |
HIP 47451 |
20.92 |
| 2026-02-13 00:00 |
09:39:47.78 |
-31:15:54.8 |
HIP 47451 |
21.53 |
| 2026-02-13 12:00 |
09:39:37.04 |
-31:15:57.4 |
HIP 47451 |
22.35 |
| 2026-02-14 00:00 |
09:39:26.30 |
-31:15:58.9 |
HIP 47451 |
23.34 |
| 2026-02-14 12:00 |
09:39:15.57 |
-31:15:59.3 |
HIP 47451 |
24.50 |
| 2026-02-15 00:00 |
09:39:04.84 |
-31:15:58.6 |
HIP 47451 |
25.80 |
| 2026-02-15 12:00 |
09:38:54.12 |
-31:15:56.8 |
HIP 47451 |
27.21 |
| 2026-02-16 00:00 |
09:38:43.42 |
-31:15:53.9 |
HIP 47210 |
25.61 |
| 2026-02-16 12:00 |
09:38:32.72 |
-31:15:50.0 |
HIP 47210 |
23.95 |
| 2026-02-17 00:00 |
09:38:22.04 |
-31:15:44.9 |
HIP 47210 |
22.40 |
| 2026-02-17 12:00 |
09:38:11.37 |
-31:15:38.7 |
HIP 47210 |
20.97 |
| 2026-02-18 00:00 |
09:38:00.71 |
-31:15:31.5 |
HIP 47210 |
19.69 |
| 2026-02-18 12:00 |
09:37:50.07 |
-31:15:23.2 |
HIP 47210 |
18.59 |
| 2026-02-19 00:00 |
09:37:39.45 |
-31:15:13.9 |
HIP 47210 |
17.69 |
| 2026-02-19 12:00 |
09:37:28.85 |
-31:15:03.4 |
HIP 47210 |
17.04 |
| 2026-02-20 00:00 |
09:37:18.27 |
-31:14:52.0 |
HIP 47108 |
16.04 |
| 2026-02-20 12:00 |
09:37:07.70 |
-31:14:39.5 |
HIP 47108 |
13.77 |
| 2026-02-21 00:00 |
09:36:57.17 |
-31:14:25.9 |
HIP 47108 |
11.51 |
| 2026-02-21 12:00 |
09:36:46.65 |
-31:14:11.3 |
HIP 47108 |
9.26 |
| 2026-02-22 00:00 |
09:36:36.16 |
-31:13:55.7 |
HIP 47108 |
7.01 |
| 2026-02-22 12:00 |
09:36:25.70 |
-31:13:39.0 |
HIP 47108 |
4.78 |
| 2026-02-23 00:00 |
09:36:15.26 |
-31:13:21.4 |
HIP 47108 |
2.61 |
| 2026-02-23 12:00 |
09:36:04.85 |
-31:13:02.7 |
HIP 47108 |
0.95 |
| 2026-02-24 00:00 |
09:35:54.48 |
-31:12:43.0 |
HIP 47108 |
2.26 |