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) |
| 2026-09-20 00:00 |
07:14:18.08 |
-13:07:20.8 |
HIP 34884 |
17.57 |
| 2026-09-20 12:00 |
07:14:19.95 |
-13:08:29.4 |
HIP 34884 |
18.05 |
| 2026-09-21 00:00 |
07:14:21.76 |
-13:09:38.1 |
HIP 34884 |
18.58 |
| 2026-09-21 12:00 |
07:14:23.52 |
-13:10:47.0 |
HIP 34884 |
19.17 |
| 2026-09-22 00:00 |
07:14:25.24 |
-13:11:55.9 |
HIP 34884 |
19.80 |
| 2026-09-22 12:00 |
07:14:26.90 |
-13:13:04.9 |
HIP 34884 |
20.47 |
| 2026-09-23 00:00 |
07:14:28.50 |
-13:14:14.1 |
HIP 34884 |
21.18 |
| 2026-09-23 12:00 |
07:14:30.06 |
-13:15:23.3 |
HIP 34884 |
21.93 |
| 2026-09-24 00:00 |
07:14:31.57 |
-13:16:32.6 |
HIP 34884 |
22.70 |
| 2026-09-24 12:00 |
07:14:33.02 |
-13:17:42.0 |
HIP 34884 |
23.50 |
| 2026-09-25 00:00 |
07:14:34.42 |
-13:18:51.4 |
HIP 34884 |
24.32 |
| 2026-09-25 12:00 |
07:14:35.76 |
-13:20:01.0 |
HIP 35139 |
25.02 |
| 2026-09-26 00:00 |
07:14:37.06 |
-13:21:10.6 |
HIP 35139 |
25.60 |
| 2026-09-26 12:00 |
07:14:38.30 |
-13:22:20.3 |
HIP 35139 |
26.23 |
| 2026-09-27 00:00 |
07:14:39.49 |
-13:23:30.0 |
HIP 35139 |
26.91 |
| 2026-09-27 12:00 |
07:14:40.62 |
-13:24:39.8 |
HIP 35139 |
27.64 |
| 2026-09-28 00:00 |
07:14:41.71 |
-13:25:49.7 |
HIP 35139 |
28.40 |
| 2026-09-28 12:00 |
07:14:42.74 |
-13:26:59.6 |
HIP 35217 |
29.10 |
| 2026-09-29 00:00 |
07:14:43.71 |
-13:28:09.6 |
HIP 35217 |
28.88 |
| 2026-09-29 12:00 |
07:14:44.63 |
-13:29:19.6 |
HIP 35217 |
28.71 |
| 2026-09-30 00:00 |
07:14:45.50 |
-13:30:29.7 |
HIP 35217 |
28.61 |
| 2026-09-30 12:00 |
07:14:46.31 |
-13:31:39.8 |
HIP 35217 |
28.56 |
| 2026-10-01 00:00 |
07:14:47.07 |
-13:32:49.9 |
HIP 35217 |
28.59 |
| 2026-10-01 12:00 |
07:14:47.77 |
-13:34:00.1 |
HIP 35217 |
28.67 |
| 2026-10-02 00:00 |
07:14:48.42 |
-13:35:10.3 |
HIP 35217 |
28.81 |
| 2026-10-02 12:00 |
07:14:49.02 |
-13:36:20.5 |
HIP 35217 |
29.02 |
| 2026-10-03 00:00 |
07:14:49.55 |
-13:37:30.8 |
HIP 35220 |
28.74 |
| 2026-10-03 12:00 |
07:14:50.04 |
-13:38:41.0 |
HIP 35220 |
28.51 |
| 2026-10-04 00:00 |
07:14:50.47 |
-13:39:51.3 |
HIP 35220 |
28.34 |
| 2026-10-04 12:00 |
07:14:50.84 |
-13:41:01.6 |
HIP 35220 |
28.23 |
| 2026-10-05 00:00 |
07:14:51.16 |
-13:42:11.9 |
HIP 35220 |
28.19 |
| 2026-10-05 12:00 |
07:14:51.42 |
-13:43:22.2 |
HIP 35220 |
28.20 |
| 2026-10-06 00:00 |
07:14:51.62 |
-13:44:32.5 |
HIP 35220 |
28.28 |
| 2026-10-06 12:00 |
07:14:51.77 |
-13:45:42.8 |
HIP 35165 |
27.82 |
| 2026-10-07 00:00 |
07:14:51.86 |
-13:46:53.0 |
HIP 35165 |
26.92 |
| 2026-10-07 12:00 |
07:14:51.90 |
-13:48:03.3 |
HIP 35165 |
26.05 |
| 2026-10-08 00:00 |
07:14:51.88 |
-13:49:13.5 |
HIP 35165 |
25.22 |
| 2026-10-08 12:00 |
07:14:51.80 |
-13:50:23.7 |
HIP 35165 |
24.43 |
| 2026-10-09 00:00 |
07:14:51.66 |
-13:51:33.9 |
HIP 35165 |
23.68 |
| 2026-10-09 12:00 |
07:14:51.47 |
-13:52:44.0 |
HIP 35165 |
22.98 |
| 2026-10-10 00:00 |
07:14:51.22 |
-13:53:54.1 |
HIP 35165 |
22.32 |
| 2026-10-10 12:00 |
07:14:50.92 |
-13:55:04.2 |
HIP 35165 |
21.72 |
| 2026-10-11 00:00 |
07:14:50.56 |
-13:56:14.2 |
HIP 35165 |
21.19 |