メタデータ
| 項目 |
値 |
| Designation |
C/2019 Y1 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-03-15T13:31:42.720960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:34:02Z |
| Obs used |
1010 |
| NEO |
- |
| M1 |
11.900 |
| K1 |
21.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-12-16T05:25:48.432000Z |
| Discovery magnitude (MPC) |
17.90 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) |
2020-04-12.0000000 |
| e |
0.99650778 |
| q (au) |
0.837824 |
| a (au) |
239.911751 |
| i (deg) |
73.348136 |
| Ω (om, deg) |
31.366339 |
| ω (w, deg) |
57.498171 |
| M (ma, deg) |
0.007277 |
等級
散乱 + 全体線形
$$
M_a = (10.361 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.361 |
| n |
6.000 |
| gf |
1.000 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2019-12-16 |
2020-01-18 |
+16.5581 |
-1.194 |
| 2020-01-18 |
2020-03-15 |
+7.5651 |
-0.659 |
| 2020-03-15 |
2020-07-12 |
+2.0051 |
-1.445 |
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) |
| 2026-06-01 00:00 |
13:33:30.32 |
-45:36:13.8 |
HIP 66105 |
6.44 |
| 2026-06-01 12:00 |
13:33:23.97 |
-45:35:17.8 |
HIP 66105 |
5.00 |
| 2026-06-02 00:00 |
13:33:17.69 |
-45:34:21.7 |
HIP 66105 |
3.56 |
| 2026-06-02 12:00 |
13:33:11.47 |
-45:33:25.4 |
HIP 66105 |
2.13 |
| 2026-06-03 00:00 |
13:33:05.31 |
-45:32:29.0 |
HIP 66105 |
0.74 |
| 2026-06-03 12:00 |
13:32:59.21 |
-45:31:32.4 |
HIP 66105 |
0.80 |
| 2026-06-04 00:00 |
13:32:53.18 |
-45:30:35.7 |
HIP 66105 |
2.18 |
| 2026-06-04 12:00 |
13:32:47.22 |
-45:29:38.9 |
HIP 66105 |
3.58 |
| 2026-06-05 00:00 |
13:32:41.31 |
-45:28:41.9 |
HIP 66105 |
4.98 |
| 2026-06-05 12:00 |
13:32:35.47 |
-45:27:44.9 |
HIP 66105 |
6.38 |
| 2026-06-06 00:00 |
13:32:29.70 |
-45:26:47.7 |
HIP 66105 |
7.76 |
| 2026-06-06 12:00 |
13:32:23.99 |
-45:25:50.5 |
HIP 66105 |
9.15 |
| 2026-06-07 00:00 |
13:32:18.35 |
-45:24:53.1 |
HIP 66105 |
10.52 |
| 2026-06-07 12:00 |
13:32:12.77 |
-45:23:55.6 |
HIP 66105 |
11.89 |
| 2026-06-08 00:00 |
13:32:07.26 |
-45:22:58.1 |
HIP 66105 |
13.25 |
| 2026-06-08 12:00 |
13:32:01.81 |
-45:22:00.5 |
HIP 66105 |
14.60 |
| 2026-06-09 00:00 |
13:31:56.43 |
-45:21:02.8 |
HIP 66105 |
15.95 |
| 2026-06-09 12:00 |
13:31:51.12 |
-45:20:05.0 |
HIP 66105 |
17.29 |
| 2026-06-10 00:00 |
13:31:45.88 |
-45:19:07.2 |
HIP 66105 |
18.62 |
| 2026-06-10 12:00 |
13:31:40.70 |
-45:18:09.3 |
HIP 66105 |
19.94 |
| 2026-06-11 00:00 |
13:31:35.60 |
-45:17:11.4 |
HIP 66105 |
21.26 |
| 2026-06-11 12:00 |
13:31:30.56 |
-45:16:13.4 |
HIP 66105 |
22.57 |
| 2026-06-12 00:00 |
13:31:25.59 |
-45:15:15.4 |
HIP 65820 |
23.64 |
| 2026-06-12 12:00 |
13:31:20.69 |
-45:14:17.4 |
HIP 65820 |
23.54 |
| 2026-06-13 00:00 |
13:31:15.85 |
-45:13:19.3 |
HIP 65820 |
23.51 |
| 2026-06-13 12:00 |
13:31:11.09 |
-45:12:21.2 |
HIP 65820 |
23.57 |
| 2026-06-14 00:00 |
13:31:06.40 |
-45:11:23.1 |
HIP 65820 |
23.70 |
| 2026-06-14 12:00 |
13:31:01.78 |
-45:10:24.9 |
HIP 65820 |
23.91 |
| 2026-06-15 00:00 |
13:30:57.22 |
-45:09:26.8 |
HIP 65825 |
22.73 |
| 2026-06-15 12:00 |
13:30:52.74 |
-45:08:28.7 |
HIP 65825 |
21.48 |
| 2026-06-16 00:00 |
13:30:48.33 |
-45:07:30.6 |
HIP 65825 |
20.24 |
| 2026-06-16 12:00 |
13:30:43.99 |
-45:06:32.5 |
HIP 65825 |
19.00 |
| 2026-06-17 00:00 |
13:30:39.73 |
-45:05:34.4 |
HIP 65825 |
17.77 |
| 2026-06-17 12:00 |
13:30:35.53 |
-45:04:36.3 |
HIP 65825 |
16.56 |
| 2026-06-18 00:00 |
13:30:31.40 |
-45:03:38.3 |
HIP 65825 |
15.35 |
| 2026-06-18 12:00 |
13:30:27.35 |
-45:02:40.3 |
HIP 65825 |
14.14 |
| 2026-06-19 00:00 |
13:30:23.37 |
-45:01:42.4 |
HIP 65825 |
12.95 |
| 2026-06-19 12:00 |
13:30:19.46 |
-45:00:44.5 |
HIP 65825 |
11.76 |
| 2026-06-20 00:00 |
13:30:15.62 |
-44:59:46.6 |
HIP 65825 |
10.59 |
| 2026-06-20 12:00 |
13:30:11.86 |
-44:58:48.9 |
HIP 65825 |
9.42 |
| 2026-06-21 00:00 |
13:30:08.17 |
-44:57:51.1 |
HIP 65825 |
8.26 |
| 2026-06-21 12:00 |
13:30:04.55 |
-44:56:53.5 |
HIP 65825 |
7.11 |
| 2026-06-22 00:00 |
13:30:01.00 |
-44:55:55.9 |
HIP 65825 |
5.98 |