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) |
| 2026-09-20 00:00 |
13:37:12.16 |
-43:24:11.1 |
HIP 66431 |
37.31 |
| 2026-09-20 12:00 |
13:37:19.06 |
-43:24:19.0 |
HIP 66431 |
37.49 |
| 2026-09-21 00:00 |
13:37:25.98 |
-43:24:27.3 |
HIP 66431 |
37.71 |
| 2026-09-21 12:00 |
13:37:32.94 |
-43:24:36.1 |
HIP 66431 |
37.99 |
| 2026-09-22 00:00 |
13:37:39.92 |
-43:24:45.3 |
HIP 66431 |
38.31 |
| 2026-09-22 12:00 |
13:37:46.92 |
-43:24:55.0 |
HIP 66431 |
38.68 |
| 2026-09-23 00:00 |
13:37:53.95 |
-43:25:05.1 |
HIP 66431 |
39.10 |
| 2026-09-23 12:00 |
13:38:01.01 |
-43:25:15.7 |
HIP 66515 |
39.37 |
| 2026-09-24 00:00 |
13:38:08.09 |
-43:25:26.8 |
HIP 66515 |
39.56 |
| 2026-09-24 12:00 |
13:38:15.20 |
-43:25:38.3 |
HIP 66515 |
39.80 |
| 2026-09-25 00:00 |
13:38:22.33 |
-43:25:50.2 |
HIP 66515 |
40.09 |
| 2026-09-25 12:00 |
13:38:29.48 |
-43:26:02.6 |
HIP 66515 |
40.42 |
| 2026-09-26 00:00 |
13:38:36.66 |
-43:26:15.5 |
HIP 66515 |
40.81 |
| 2026-09-26 12:00 |
13:38:43.86 |
-43:26:28.8 |
HIP 66850 |
40.06 |
| 2026-09-27 00:00 |
13:38:51.08 |
-43:26:42.6 |
HIP 66850 |
38.99 |
| 2026-09-27 12:00 |
13:38:58.32 |
-43:26:56.7 |
HIP 66850 |
37.93 |
| 2026-09-28 00:00 |
13:39:05.59 |
-43:27:11.4 |
HIP 66850 |
36.90 |
| 2026-09-28 12:00 |
13:39:12.87 |
-43:27:26.5 |
HIP 66850 |
35.88 |
| 2026-09-29 00:00 |
13:39:20.18 |
-43:27:42.0 |
HIP 66850 |
34.89 |
| 2026-09-29 12:00 |
13:39:27.51 |
-43:27:58.0 |
HIP 66850 |
33.93 |
| 2026-09-30 00:00 |
13:39:34.86 |
-43:28:14.4 |
HIP 66850 |
32.99 |
| 2026-09-30 12:00 |
13:39:42.22 |
-43:28:31.2 |
HIP 66850 |
32.09 |
| 2026-10-01 00:00 |
13:39:49.61 |
-43:28:48.5 |
HIP 66850 |
31.22 |
| 2026-10-01 12:00 |
13:39:57.01 |
-43:29:06.3 |
HIP 66850 |
30.40 |
| 2026-10-02 00:00 |
13:40:04.44 |
-43:29:24.5 |
HIP 66850 |
29.61 |
| 2026-10-02 12:00 |
13:40:11.88 |
-43:29:43.1 |
HIP 66850 |
28.88 |
| 2026-10-03 00:00 |
13:40:19.34 |
-43:30:02.1 |
HIP 66850 |
28.20 |
| 2026-10-03 12:00 |
13:40:26.81 |
-43:30:21.6 |
HIP 66850 |
27.57 |
| 2026-10-04 00:00 |
13:40:34.30 |
-43:30:41.5 |
HIP 66850 |
27.01 |
| 2026-10-04 12:00 |
13:40:41.81 |
-43:31:01.9 |
HIP 66850 |
26.52 |
| 2026-10-05 00:00 |
13:40:49.34 |
-43:31:22.7 |
HIP 66850 |
26.09 |
| 2026-10-05 12:00 |
13:40:56.88 |
-43:31:43.9 |
HIP 66850 |
25.75 |
| 2026-10-06 00:00 |
13:41:04.43 |
-43:32:05.6 |
HIP 66850 |
25.48 |
| 2026-10-06 12:00 |
13:41:12.00 |
-43:32:27.7 |
HIP 66850 |
25.29 |
| 2026-10-07 00:00 |
13:41:19.58 |
-43:32:50.2 |
HIP 66850 |
25.19 |
| 2026-10-07 12:00 |
13:41:27.18 |
-43:33:13.1 |
HIP 66850 |
25.18 |
| 2026-10-08 00:00 |
13:41:34.79 |
-43:33:36.5 |
HIP 66850 |
25.26 |
| 2026-10-08 12:00 |
13:41:42.41 |
-43:34:00.3 |
HIP 66864 |
24.76 |
| 2026-10-09 00:00 |
13:41:50.04 |
-43:34:24.5 |
HIP 66864 |
24.06 |
| 2026-10-09 12:00 |
13:41:57.69 |
-43:34:49.2 |
HIP 66864 |
23.43 |
| 2026-10-10 00:00 |
13:42:05.35 |
-43:35:14.2 |
HIP 66864 |
22.86 |
| 2026-10-10 12:00 |
13:42:13.01 |
-43:35:39.7 |
HIP 66864 |
22.36 |
| 2026-10-11 00:00 |
13:42:20.69 |
-43:36:05.6 |
HIP 67024 |
21.83 |