メタデータ
| 項目 |
値 |
| Designation |
C/2017 M4 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-01-18T08:09:45.547200Z |
| Orbit solution date (soln_date, UTC) |
2022-07-31T01:42:28Z |
| Obs used |
3296 |
| NEO |
- |
| M1 |
9.400 |
| K1 |
6.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-06-17.0000000 |
| e |
1.00108487 |
| q (au) |
3.251701 |
| a (au) |
-2997.319774 |
| i (deg) |
105.657087 |
| Ω (om, deg) |
65.868353 |
| ω (w, deg) |
167.652626 |
| M (ma, deg) |
-0.001293 |
等級
散乱 + 全体線形
$$
M_a = (7.294 + 2.998\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
7.294 |
| n |
2.998 |
| gf |
0.999 |
| gb |
-1.000 |
| k |
1.000 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
06:14:10.37 |
-32:16:51.7 |
HIP 29475 |
19.87 |
| 2026-07-29 12:00 |
06:14:15.79 |
-32:17:23.5 |
HIP 29475 |
21.09 |
| 2026-07-30 00:00 |
06:14:21.17 |
-32:17:55.9 |
HIP 29710 |
20.16 |
| 2026-07-30 12:00 |
06:14:26.53 |
-32:18:28.9 |
HIP 29710 |
18.97 |
| 2026-07-31 00:00 |
06:14:31.85 |
-32:19:02.3 |
HIP 29710 |
17.80 |
| 2026-07-31 12:00 |
06:14:37.14 |
-32:19:36.2 |
HIP 29710 |
16.63 |
| 2026-08-01 00:00 |
06:14:42.39 |
-32:20:10.6 |
HIP 29710 |
15.47 |
| 2026-08-01 12:00 |
06:14:47.61 |
-32:20:45.5 |
HIP 29710 |
14.33 |
| 2026-08-02 00:00 |
06:14:52.80 |
-32:21:20.9 |
HIP 29710 |
13.20 |
| 2026-08-02 12:00 |
06:14:57.96 |
-32:21:56.8 |
HIP 29710 |
12.09 |
| 2026-08-03 00:00 |
06:15:03.08 |
-32:22:33.2 |
HIP 29710 |
11.01 |
| 2026-08-03 12:00 |
06:15:08.16 |
-32:23:10.0 |
HIP 29710 |
9.96 |
| 2026-08-04 00:00 |
06:15:13.21 |
-32:23:47.4 |
HIP 29710 |
8.95 |
| 2026-08-04 12:00 |
06:15:18.23 |
-32:24:25.2 |
HIP 29710 |
8.01 |
| 2026-08-05 00:00 |
06:15:23.21 |
-32:25:03.5 |
HIP 29710 |
7.14 |
| 2026-08-05 12:00 |
06:15:28.15 |
-32:25:42.3 |
HIP 29710 |
6.38 |
| 2026-08-06 00:00 |
06:15:33.06 |
-32:26:21.6 |
HIP 29710 |
5.78 |
| 2026-08-06 12:00 |
06:15:37.93 |
-32:27:01.3 |
HIP 29710 |
5.39 |
| 2026-08-07 00:00 |
06:15:42.76 |
-32:27:41.6 |
HIP 29710 |
5.24 |
| 2026-08-07 12:00 |
06:15:47.55 |
-32:28:22.2 |
HIP 29710 |
5.37 |
| 2026-08-08 00:00 |
06:15:52.31 |
-32:29:03.4 |
HIP 29710 |
5.74 |
| 2026-08-08 12:00 |
06:15:57.03 |
-32:29:45.0 |
HIP 29710 |
6.32 |
| 2026-08-09 00:00 |
06:16:01.71 |
-32:30:27.1 |
HIP 29802 |
6.85 |
| 2026-08-09 12:00 |
06:16:06.35 |
-32:31:09.6 |
HIP 29802 |
6.59 |
| 2026-08-10 00:00 |
06:16:10.95 |
-32:31:52.6 |
HIP 29802 |
6.55 |
| 2026-08-10 12:00 |
06:16:15.51 |
-32:32:36.0 |
HIP 29802 |
6.74 |
| 2026-08-11 00:00 |
06:16:20.03 |
-32:33:19.9 |
HIP 29802 |
7.14 |
| 2026-08-11 12:00 |
06:16:24.51 |
-32:34:04.2 |
HIP 29802 |
7.72 |
| 2026-08-12 00:00 |
06:16:28.94 |
-32:34:48.9 |
HIP 29802 |
8.43 |
| 2026-08-12 12:00 |
06:16:33.34 |
-32:35:34.1 |
HIP 29802 |
9.25 |
| 2026-08-13 00:00 |
06:16:37.69 |
-32:36:19.8 |
HIP 29802 |
10.16 |
| 2026-08-13 12:00 |
06:16:42.00 |
-32:37:05.8 |
HIP 29802 |
11.12 |
| 2026-08-14 00:00 |
06:16:46.27 |
-32:37:52.3 |
HIP 29802 |
12.12 |
| 2026-08-14 12:00 |
06:16:50.50 |
-32:38:39.2 |
HIP 29802 |
13.16 |
| 2026-08-15 00:00 |
06:16:54.68 |
-32:39:26.5 |
HIP 29802 |
14.23 |
| 2026-08-15 12:00 |
06:16:58.81 |
-32:40:14.3 |
HIP 29802 |
15.31 |
| 2026-08-16 00:00 |
06:17:02.91 |
-32:41:02.4 |
HIP 29802 |
16.41 |
| 2026-08-16 12:00 |
06:17:06.96 |
-32:41:51.0 |
HIP 29802 |
17.52 |
| 2026-08-17 00:00 |
06:17:10.96 |
-32:42:39.9 |
HIP 29802 |
18.64 |
| 2026-08-17 12:00 |
06:17:14.92 |
-32:43:29.3 |
HIP 29802 |
19.77 |
| 2026-08-18 00:00 |
06:17:18.83 |
-32:44:19.0 |
HIP 29802 |
20.90 |
| 2026-08-18 12:00 |
06:17:22.70 |
-32:45:09.2 |
HIP 29802 |
22.04 |
| 2026-08-19 00:00 |
06:17:26.52 |
-32:45:59.7 |
HIP 29802 |
23.17 |