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) |
| 2026-07-29 00:00 |
07:07:05.37 |
-11:26:56.2 |
HIP 34325 |
7.62 |
| 2026-07-29 12:00 |
07:07:11.05 |
-11:27:36.8 |
HIP 34325 |
8.74 |
| 2026-07-30 00:00 |
07:07:16.71 |
-11:28:17.7 |
HIP 34325 |
9.98 |
| 2026-07-30 12:00 |
07:07:22.35 |
-11:28:59.1 |
HIP 34325 |
11.30 |
| 2026-07-31 00:00 |
07:07:27.97 |
-11:29:40.8 |
HIP 34325 |
12.67 |
| 2026-07-31 12:00 |
07:07:33.57 |
-11:30:22.9 |
HIP 34325 |
14.08 |
| 2026-08-01 00:00 |
07:07:39.15 |
-11:31:05.3 |
HIP 34325 |
15.51 |
| 2026-08-01 12:00 |
07:07:44.71 |
-11:31:48.2 |
HIP 34325 |
16.97 |
| 2026-08-02 00:00 |
07:07:50.25 |
-11:32:31.3 |
HIP 34499 |
15.77 |
| 2026-08-02 12:00 |
07:07:55.77 |
-11:33:14.9 |
HIP 34499 |
14.57 |
| 2026-08-03 00:00 |
07:08:01.27 |
-11:33:58.8 |
HIP 34499 |
13.45 |
| 2026-08-03 12:00 |
07:08:06.75 |
-11:34:43.1 |
HIP 34499 |
12.43 |
| 2026-08-04 00:00 |
07:08:12.20 |
-11:35:27.7 |
HIP 34499 |
11.53 |
| 2026-08-04 12:00 |
07:08:17.64 |
-11:36:12.8 |
HIP 34499 |
10.78 |
| 2026-08-05 00:00 |
07:08:23.05 |
-11:36:58.1 |
HIP 34499 |
10.21 |
| 2026-08-05 12:00 |
07:08:28.43 |
-11:37:43.9 |
HIP 34499 |
9.85 |
| 2026-08-06 00:00 |
07:08:33.80 |
-11:38:29.9 |
HIP 34499 |
9.74 |
| 2026-08-06 12:00 |
07:08:39.14 |
-11:39:16.4 |
HIP 34499 |
9.86 |
| 2026-08-07 00:00 |
07:08:44.45 |
-11:40:03.2 |
HIP 34499 |
10.22 |
| 2026-08-07 12:00 |
07:08:49.75 |
-11:40:50.3 |
HIP 34499 |
10.79 |
| 2026-08-08 00:00 |
07:08:55.01 |
-11:41:37.8 |
HIP 34499 |
11.54 |
| 2026-08-08 12:00 |
07:09:00.25 |
-11:42:25.7 |
HIP 34499 |
12.44 |
| 2026-08-09 00:00 |
07:09:05.47 |
-11:43:13.9 |
HIP 34443 |
13.02 |
| 2026-08-09 12:00 |
07:09:10.66 |
-11:44:02.4 |
HIP 34443 |
13.61 |
| 2026-08-10 00:00 |
07:09:15.82 |
-11:44:51.3 |
HIP 34612 |
13.23 |
| 2026-08-10 12:00 |
07:09:20.96 |
-11:45:40.5 |
HIP 34612 |
11.81 |
| 2026-08-11 00:00 |
07:09:26.07 |
-11:46:30.1 |
HIP 34612 |
10.43 |
| 2026-08-11 12:00 |
07:09:31.15 |
-11:47:20.0 |
HIP 34612 |
9.09 |
| 2026-08-12 00:00 |
07:09:36.21 |
-11:48:10.2 |
HIP 34612 |
7.82 |
| 2026-08-12 12:00 |
07:09:41.23 |
-11:49:00.8 |
HIP 34612 |
6.64 |
| 2026-08-13 00:00 |
07:09:46.23 |
-11:49:51.7 |
HIP 34612 |
5.63 |
| 2026-08-13 12:00 |
07:09:51.20 |
-11:50:42.9 |
HIP 34612 |
4.87 |
| 2026-08-14 00:00 |
07:09:56.14 |
-11:51:34.5 |
HIP 34612 |
4.50 |
| 2026-08-14 12:00 |
07:10:01.05 |
-11:52:26.4 |
HIP 34612 |
4.62 |
| 2026-08-15 00:00 |
07:10:05.93 |
-11:53:18.6 |
HIP 34612 |
5.17 |
| 2026-08-15 12:00 |
07:10:10.78 |
-11:54:11.1 |
HIP 34612 |
6.06 |
| 2026-08-16 00:00 |
07:10:15.59 |
-11:55:04.0 |
HIP 34612 |
7.14 |
| 2026-08-16 12:00 |
07:10:20.38 |
-11:55:57.2 |
HIP 34612 |
8.34 |
| 2026-08-17 00:00 |
07:10:25.13 |
-11:56:50.6 |
HIP 34612 |
9.62 |
| 2026-08-17 12:00 |
07:10:29.86 |
-11:57:44.4 |
HIP 34612 |
10.95 |
| 2026-08-18 00:00 |
07:10:34.55 |
-11:58:38.5 |
HIP 34710 |
11.24 |
| 2026-08-18 12:00 |
07:10:39.21 |
-11:59:32.9 |
HIP 34710 |
9.87 |
| 2026-08-19 00:00 |
07:10:43.83 |
-12:00:27.6 |
HIP 34710 |
8.54 |