C/2019 K8 (ATLAS)
メタデータ
| 項目 |
値 |
| Designation |
C/2019 K8 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-07-21T05:16:17.423040Z |
| Orbit solution date (soln_date, UTC) |
2021-09-04T23:43:00Z |
| Obs used |
1385 |
| NEO |
- |
| M1 |
6.800 |
| K1 |
17.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2019-05-27T13:35:12.768000Z |
| Discovery magnitude (MPC) |
17.94 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2019-07-10.0000000 |
| e |
0.99773063 |
| q (au) |
3.195048 |
| a (au) |
1407.899123 |
| i (deg) |
93.222155 |
| Ω (om, deg) |
291.046375 |
| ω (w, deg) |
85.352840 |
| M (ma, deg) |
359.999791 |
等級
散乱 + 全体線形
$$
M_a = (11.128 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
11.128 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2019-07-21 |
2020-05-19 |
+17.4834 |
-9.014 |
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) |
| 2026-02-03 00:00 |
06:56:48.24 |
-13:10:55.4 |
HIP 33376 |
8.56 |
| 2026-02-03 12:00 |
06:56:41.61 |
-13:10:29.9 |
HIP 33376 |
7.46 |
| 2026-02-04 00:00 |
06:56:35.01 |
-13:10:04.0 |
HIP 33376 |
6.60 |
| 2026-02-04 12:00 |
06:56:28.45 |
-13:09:37.7 |
HIP 33376 |
6.08 |
| 2026-02-05 00:00 |
06:56:21.93 |
-13:09:10.9 |
HIP 33376 |
5.98 |
| 2026-02-05 12:00 |
06:56:15.46 |
-13:08:43.7 |
HIP 33376 |
6.30 |
| 2026-02-06 00:00 |
06:56:09.02 |
-13:08:16.1 |
HIP 33376 |
7.00 |
| 2026-02-06 12:00 |
06:56:02.62 |
-13:07:48.1 |
HIP 33376 |
7.96 |
| 2026-02-07 00:00 |
06:55:56.27 |
-13:07:19.6 |
HIP 33376 |
9.10 |
| 2026-02-07 12:00 |
06:55:49.96 |
-13:06:50.8 |
HIP 33376 |
10.36 |
| 2026-02-08 00:00 |
06:55:43.69 |
-13:06:21.5 |
HIP 33376 |
11.69 |
| 2026-02-08 12:00 |
06:55:37.47 |
-13:05:51.9 |
HIP 33376 |
13.07 |
| 2026-02-09 00:00 |
06:55:31.29 |
-13:05:21.9 |
HIP 33376 |
14.48 |
| 2026-02-09 12:00 |
06:55:25.15 |
-13:04:51.4 |
HIP 33376 |
15.92 |
| 2026-02-10 00:00 |
06:55:19.06 |
-13:04:20.6 |
HIP 33376 |
17.36 |
| 2026-02-10 12:00 |
06:55:13.01 |
-13:03:49.4 |
HIP 33376 |
18.82 |
| 2026-02-11 00:00 |
06:55:07.01 |
-13:03:17.8 |
HIP 33119 |
19.84 |
| 2026-02-11 12:00 |
06:55:01.06 |
-13:02:45.9 |
HIP 33119 |
18.75 |
| 2026-02-12 00:00 |
06:54:55.15 |
-13:02:13.6 |
HIP 33119 |
17.74 |
| 2026-02-12 12:00 |
06:54:49.29 |
-13:01:40.9 |
HIP 33119 |
16.83 |
| 2026-02-13 00:00 |
06:54:43.48 |
-13:01:07.8 |
HIP 33119 |
16.02 |
| 2026-02-13 12:00 |
06:54:37.72 |
-13:00:34.4 |
HIP 33119 |
15.33 |
| 2026-02-14 00:00 |
06:54:32.00 |
-13:00:00.7 |
HIP 33119 |
14.77 |
| 2026-02-14 12:00 |
06:54:26.34 |
-12:59:26.6 |
HIP 33119 |
14.36 |
| 2026-02-15 00:00 |
06:54:20.72 |
-12:58:52.2 |
HIP 33119 |
14.11 |
| 2026-02-15 12:00 |
06:54:15.15 |
-12:58:17.4 |
HIP 33119 |
14.03 |
| 2026-02-16 00:00 |
06:54:09.64 |
-12:57:42.3 |
HIP 33119 |
14.10 |
| 2026-02-16 12:00 |
06:54:04.17 |
-12:57:06.9 |
HIP 33119 |
14.34 |
| 2026-02-17 00:00 |
06:53:58.75 |
-12:56:31.2 |
HIP 33119 |
14.72 |
| 2026-02-17 12:00 |
06:53:53.39 |
-12:55:55.1 |
HIP 33119 |
15.24 |
| 2026-02-18 00:00 |
06:53:48.08 |
-12:55:18.7 |
HIP 33119 |
15.87 |
| 2026-02-18 12:00 |
06:53:42.82 |
-12:54:42.1 |
HIP 33119 |
16.61 |
| 2026-02-19 00:00 |
06:53:37.61 |
-12:54:05.1 |
HIP 33119 |
17.43 |
| 2026-02-19 12:00 |
06:53:32.46 |
-12:53:27.8 |
HIP 33119 |
18.33 |
| 2026-02-20 00:00 |
06:53:27.36 |
-12:52:50.3 |
HIP 33119 |
19.28 |
| 2026-02-20 12:00 |
06:53:22.32 |
-12:52:12.5 |
HIP 33119 |
20.29 |
| 2026-02-21 00:00 |
06:53:17.32 |
-12:51:34.4 |
HIP 33113 |
21.31 |
| 2026-02-21 12:00 |
06:53:12.39 |
-12:50:56.0 |
HIP 33113 |
22.35 |
| 2026-02-22 00:00 |
06:53:07.50 |
-12:50:17.3 |
HIP 32932 |
22.72 |
| 2026-02-22 12:00 |
06:53:02.68 |
-12:49:38.4 |
HIP 32932 |
21.40 |
| 2026-02-23 00:00 |
06:52:57.90 |
-12:48:59.3 |
HIP 32932 |
20.09 |
| 2026-02-23 12:00 |
06:52:53.19 |
-12:48:19.8 |
HIP 32932 |
18.80 |
| 2026-02-24 00:00 |
06:52:48.53 |
-12:47:40.2 |
HIP 32932 |
17.52 |