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) |
| 2026-03-26 00:00 |
06:49:57.61 |
-12:03:41.6 |
HIP 32640 |
24.28 |
| 2026-03-26 12:00 |
06:49:56.64 |
-12:02:56.4 |
HIP 32640 |
23.69 |
| 2026-03-27 00:00 |
06:49:55.73 |
-12:02:11.3 |
HIP 32640 |
23.13 |
| 2026-03-27 12:00 |
06:49:54.88 |
-12:01:26.3 |
HIP 32640 |
22.60 |
| 2026-03-28 00:00 |
06:49:54.10 |
-12:00:41.3 |
HIP 32640 |
22.09 |
| 2026-03-28 12:00 |
06:49:53.37 |
-11:59:56.4 |
HIP 32640 |
21.62 |
| 2026-03-29 00:00 |
06:49:52.71 |
-11:59:11.6 |
HIP 32640 |
21.18 |
| 2026-03-29 12:00 |
06:49:52.10 |
-11:58:26.9 |
HIP 32640 |
20.77 |
| 2026-03-30 00:00 |
06:49:51.56 |
-11:57:42.2 |
HIP 32640 |
20.39 |
| 2026-03-30 12:00 |
06:49:51.08 |
-11:56:57.7 |
HIP 32640 |
20.05 |
| 2026-03-31 00:00 |
06:49:50.66 |
-11:56:13.2 |
HIP 32640 |
19.75 |
| 2026-03-31 12:00 |
06:49:50.30 |
-11:55:28.9 |
HIP 32640 |
19.49 |
| 2026-04-01 00:00 |
06:49:49.99 |
-11:54:44.6 |
HIP 32640 |
19.26 |
| 2026-04-01 12:00 |
06:49:49.75 |
-11:54:00.5 |
HIP 32640 |
19.08 |
| 2026-04-02 00:00 |
06:49:49.57 |
-11:53:16.4 |
HIP 32640 |
18.94 |
| 2026-04-02 12:00 |
06:49:49.45 |
-11:52:32.5 |
HIP 32640 |
18.84 |
| 2026-04-03 00:00 |
06:49:49.39 |
-11:51:48.7 |
HIP 32640 |
18.79 |
| 2026-04-03 12:00 |
06:49:49.39 |
-11:51:05.1 |
HIP 32640 |
18.78 |
| 2026-04-04 00:00 |
06:49:49.45 |
-11:50:21.5 |
HIP 32640 |
18.81 |
| 2026-04-04 12:00 |
06:49:49.57 |
-11:49:38.1 |
HIP 32640 |
18.88 |
| 2026-04-05 00:00 |
06:49:49.74 |
-11:48:54.8 |
HIP 32758 |
18.52 |
| 2026-04-05 12:00 |
06:49:49.98 |
-11:48:11.7 |
HIP 32758 |
17.80 |
| 2026-04-06 00:00 |
06:49:50.28 |
-11:47:28.7 |
HIP 32758 |
17.08 |
| 2026-04-06 12:00 |
06:49:50.63 |
-11:46:45.8 |
HIP 32758 |
16.36 |
| 2026-04-07 00:00 |
06:49:51.04 |
-11:46:03.1 |
HIP 32758 |
15.65 |
| 2026-04-07 12:00 |
06:49:51.52 |
-11:45:20.6 |
HIP 32758 |
14.95 |
| 2026-04-08 00:00 |
06:49:52.05 |
-11:44:38.2 |
HIP 32758 |
14.24 |
| 2026-04-08 12:00 |
06:49:52.63 |
-11:43:55.9 |
HIP 32758 |
13.55 |
| 2026-04-09 00:00 |
06:49:53.28 |
-11:43:13.8 |
HIP 32758 |
12.85 |
| 2026-04-09 12:00 |
06:49:53.99 |
-11:42:31.9 |
HIP 32758 |
12.17 |
| 2026-04-10 00:00 |
06:49:54.75 |
-11:41:50.2 |
HIP 32758 |
11.49 |
| 2026-04-10 12:00 |
06:49:55.57 |
-11:41:08.7 |
HIP 32758 |
10.82 |
| 2026-04-11 00:00 |
06:49:56.45 |
-11:40:27.3 |
HIP 32758 |
10.17 |
| 2026-04-11 12:00 |
06:49:57.38 |
-11:39:46.1 |
HIP 32758 |
9.53 |
| 2026-04-12 00:00 |
06:49:58.37 |
-11:39:05.1 |
HIP 32758 |
8.91 |
| 2026-04-12 12:00 |
06:49:59.42 |
-11:38:24.3 |
HIP 32758 |
8.32 |
| 2026-04-13 00:00 |
06:50:00.53 |
-11:37:43.7 |
HIP 32758 |
7.75 |
| 2026-04-13 12:00 |
06:50:01.69 |
-11:37:03.3 |
HIP 32758 |
7.22 |
| 2026-04-14 00:00 |
06:50:02.91 |
-11:36:23.0 |
HIP 32758 |
6.74 |
| 2026-04-14 12:00 |
06:50:04.19 |
-11:35:43.0 |
HIP 32758 |
6.32 |
| 2026-04-15 00:00 |
06:50:05.52 |
-11:35:03.2 |
HIP 32758 |
5.97 |
| 2026-04-15 12:00 |
06:50:06.91 |
-11:34:23.6 |
HIP 32758 |
5.71 |
| 2026-04-16 00:00 |
06:50:08.35 |
-11:33:44.3 |
HIP 32758 |
5.55 |