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) |
| 2026-06-01 00:00 |
06:55:39.98 |
-10:55:07.6 |
HIP 33436 |
22.67 |
| 2026-06-01 12:00 |
06:55:45.27 |
-10:54:59.6 |
HIP 33436 |
21.38 |
| 2026-06-02 00:00 |
06:55:50.58 |
-10:54:52.0 |
HIP 33436 |
20.09 |
| 2026-06-02 12:00 |
06:55:55.92 |
-10:54:44.9 |
HIP 33436 |
18.79 |
| 2026-06-03 00:00 |
06:56:01.28 |
-10:54:38.1 |
HIP 33436 |
17.50 |
| 2026-06-03 12:00 |
06:56:06.67 |
-10:54:31.8 |
HIP 33436 |
16.21 |
| 2026-06-04 00:00 |
06:56:12.08 |
-10:54:25.9 |
HIP 33436 |
14.92 |
| 2026-06-04 12:00 |
06:56:17.51 |
-10:54:20.4 |
HIP 33436 |
13.63 |
| 2026-06-05 00:00 |
06:56:22.97 |
-10:54:15.3 |
HIP 33436 |
12.36 |
| 2026-06-05 12:00 |
06:56:28.45 |
-10:54:10.6 |
HIP 33436 |
11.10 |
| 2026-06-06 00:00 |
06:56:33.95 |
-10:54:06.4 |
HIP 33436 |
9.86 |
| 2026-06-06 12:00 |
06:56:39.48 |
-10:54:02.5 |
HIP 33436 |
8.65 |
| 2026-06-07 00:00 |
06:56:45.02 |
-10:53:59.1 |
HIP 33436 |
7.50 |
| 2026-06-07 12:00 |
06:56:50.59 |
-10:53:56.2 |
HIP 33436 |
6.42 |
| 2026-06-08 00:00 |
06:56:56.18 |
-10:53:53.6 |
HIP 33436 |
5.49 |
| 2026-06-08 12:00 |
06:57:01.78 |
-10:53:51.5 |
HIP 33436 |
4.77 |
| 2026-06-09 00:00 |
06:57:07.41 |
-10:53:49.8 |
HIP 33436 |
4.39 |
| 2026-06-09 12:00 |
06:57:13.06 |
-10:53:48.5 |
HIP 33458 |
3.57 |
| 2026-06-10 00:00 |
06:57:18.73 |
-10:53:47.6 |
HIP 33458 |
3.00 |
| 2026-06-10 12:00 |
06:57:24.41 |
-10:53:47.2 |
HIP 33458 |
3.02 |
| 2026-06-11 00:00 |
06:57:30.12 |
-10:53:47.2 |
HIP 33458 |
3.62 |
| 2026-06-11 12:00 |
06:57:35.84 |
-10:53:47.6 |
HIP 33458 |
4.58 |
| 2026-06-12 00:00 |
06:57:41.58 |
-10:53:48.5 |
HIP 33458 |
5.73 |
| 2026-06-12 12:00 |
06:57:47.34 |
-10:53:49.8 |
HIP 33458 |
6.98 |
| 2026-06-13 00:00 |
06:57:53.12 |
-10:53:51.5 |
HIP 33515 |
6.86 |
| 2026-06-13 12:00 |
06:57:58.91 |
-10:53:53.6 |
HIP 33515 |
6.74 |
| 2026-06-14 00:00 |
06:58:04.72 |
-10:53:56.2 |
HIP 33515 |
6.93 |
| 2026-06-14 12:00 |
06:58:10.55 |
-10:53:59.2 |
HIP 33515 |
7.40 |
| 2026-06-15 00:00 |
06:58:16.39 |
-10:54:02.7 |
HIP 33515 |
8.10 |
| 2026-06-15 12:00 |
06:58:22.24 |
-10:54:06.6 |
HIP 33515 |
9.00 |
| 2026-06-16 00:00 |
06:58:28.11 |
-10:54:10.9 |
HIP 33515 |
10.02 |
| 2026-06-16 12:00 |
06:58:34.00 |
-10:54:15.6 |
HIP 33620 |
10.78 |
| 2026-06-17 00:00 |
06:58:39.90 |
-10:54:20.8 |
HIP 33620 |
9.82 |
| 2026-06-17 12:00 |
06:58:45.81 |
-10:54:26.5 |
HIP 33620 |
8.99 |
| 2026-06-18 00:00 |
06:58:51.73 |
-10:54:32.5 |
HIP 33620 |
8.34 |
| 2026-06-18 12:00 |
06:58:57.67 |
-10:54:39.0 |
HIP 33620 |
7.91 |
| 2026-06-19 00:00 |
06:59:03.62 |
-10:54:45.9 |
HIP 33620 |
7.75 |
| 2026-06-19 12:00 |
06:59:09.58 |
-10:54:53.3 |
HIP 33620 |
7.87 |
| 2026-06-20 00:00 |
06:59:15.55 |
-10:55:01.1 |
HIP 33620 |
8.26 |
| 2026-06-20 12:00 |
06:59:21.54 |
-10:55:09.3 |
HIP 33620 |
8.88 |
| 2026-06-21 00:00 |
06:59:27.53 |
-10:55:18.0 |
HIP 33620 |
9.70 |
| 2026-06-21 12:00 |
06:59:33.53 |
-10:55:27.1 |
HIP 33620 |
10.68 |
| 2026-06-22 00:00 |
06:59:39.55 |
-10:55:36.6 |
HIP 33620 |
11.76 |