メタデータ
| 項目 |
値 |
| Designation |
C/2018 V4 (Africano) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-03-01T16:37:36.183360Z |
| Orbit solution date (soln_date, UTC) |
2022-06-20T23:12:32Z |
| Obs used |
159 |
| NEO |
- |
| M1 |
15.700 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2018-11-04T10:18:31.392000Z |
| Discovery magnitude (MPC) |
19.70 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-11-17.0000000 |
| e |
0.98482835 |
| q (au) |
3.198877 |
| a (au) |
210.845675 |
| i (deg) |
68.998987 |
| Ω (om, deg) |
78.384315 |
| ω (w, deg) |
0.008035 |
| M (ma, deg) |
359.966297 |
等級
散乱 + 全体線形
$$
M_a = (14.385 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
14.385 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.998 |
| 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 |
16:05:23.04 |
+25:04:23.1 |
HIP 78759 |
12.57 |
| 2026-07-29 12:00 |
16:05:20.27 |
+25:03:14.3 |
HIP 78759 |
13.13 |
| 2026-07-30 00:00 |
16:05:17.55 |
+25:02:05.2 |
HIP 78759 |
13.80 |
| 2026-07-30 12:00 |
16:05:14.89 |
+25:00:55.8 |
HIP 78759 |
14.57 |
| 2026-07-31 00:00 |
16:05:12.28 |
+24:59:46.1 |
HIP 78759 |
15.42 |
| 2026-07-31 12:00 |
16:05:09.72 |
+24:58:36.2 |
HIP 78759 |
16.34 |
| 2026-08-01 00:00 |
16:05:07.23 |
+24:57:25.9 |
HIP 78759 |
17.31 |
| 2026-08-01 12:00 |
16:05:04.78 |
+24:56:15.4 |
HIP 78759 |
18.33 |
| 2026-08-02 00:00 |
16:05:02.40 |
+24:55:04.6 |
HIP 78759 |
19.39 |
| 2026-08-02 12:00 |
16:05:00.07 |
+24:53:53.5 |
HIP 78759 |
20.49 |
| 2026-08-03 00:00 |
16:04:57.80 |
+24:52:42.1 |
HIP 78759 |
21.61 |
| 2026-08-03 12:00 |
16:04:55.58 |
+24:51:30.5 |
HIP 78759 |
22.76 |
| 2026-08-04 00:00 |
16:04:53.42 |
+24:50:18.6 |
HIP 78759 |
23.93 |
| 2026-08-04 12:00 |
16:04:51.31 |
+24:49:06.5 |
HIP 78759 |
25.11 |
| 2026-08-05 00:00 |
16:04:49.27 |
+24:47:54.1 |
HIP 78759 |
26.31 |
| 2026-08-05 12:00 |
16:04:47.27 |
+24:46:41.5 |
HIP 78759 |
27.52 |
| 2026-08-06 00:00 |
16:04:45.34 |
+24:45:28.6 |
HIP 78759 |
28.74 |
| 2026-08-06 12:00 |
16:04:43.46 |
+24:44:15.5 |
HIP 78759 |
29.97 |
| 2026-08-07 00:00 |
16:04:41.64 |
+24:43:02.2 |
HIP 78759 |
31.21 |
| 2026-08-07 12:00 |
16:04:39.88 |
+24:41:48.6 |
HIP 78759 |
32.46 |
| 2026-08-08 00:00 |
16:04:38.17 |
+24:40:34.9 |
HIP 78673 |
31.24 |
| 2026-08-08 12:00 |
16:04:36.53 |
+24:39:20.9 |
HIP 78673 |
29.97 |
| 2026-08-09 00:00 |
16:04:34.93 |
+24:38:06.6 |
HIP 78673 |
28.70 |
| 2026-08-09 12:00 |
16:04:33.40 |
+24:36:52.2 |
HIP 78673 |
27.43 |
| 2026-08-10 00:00 |
16:04:31.92 |
+24:35:37.6 |
HIP 78673 |
26.17 |
| 2026-08-10 12:00 |
16:04:30.51 |
+24:34:22.8 |
HIP 78673 |
24.91 |
| 2026-08-11 00:00 |
16:04:29.15 |
+24:33:07.7 |
HIP 78673 |
23.66 |
| 2026-08-11 12:00 |
16:04:27.84 |
+24:31:52.5 |
HIP 78673 |
22.42 |
| 2026-08-12 00:00 |
16:04:26.60 |
+24:30:37.1 |
HIP 78673 |
21.19 |
| 2026-08-12 12:00 |
16:04:25.41 |
+24:29:21.5 |
HIP 78673 |
19.97 |
| 2026-08-13 00:00 |
16:04:24.28 |
+24:28:05.8 |
HIP 78673 |
18.77 |
| 2026-08-13 12:00 |
16:04:23.21 |
+24:26:49.9 |
HIP 78673 |
17.58 |
| 2026-08-14 00:00 |
16:04:22.20 |
+24:25:33.8 |
HIP 78673 |
16.41 |
| 2026-08-14 12:00 |
16:04:21.25 |
+24:24:17.6 |
HIP 78673 |
15.27 |
| 2026-08-15 00:00 |
16:04:20.35 |
+24:23:01.2 |
HIP 78673 |
14.16 |
| 2026-08-15 12:00 |
16:04:19.51 |
+24:21:44.6 |
HIP 78673 |
13.09 |
| 2026-08-16 00:00 |
16:04:18.73 |
+24:20:27.9 |
HIP 78673 |
12.07 |
| 2026-08-16 12:00 |
16:04:18.01 |
+24:19:11.1 |
HIP 78673 |
11.12 |
| 2026-08-17 00:00 |
16:04:17.34 |
+24:17:54.2 |
HIP 78673 |
10.25 |
| 2026-08-17 12:00 |
16:04:16.74 |
+24:16:37.1 |
HIP 78673 |
9.49 |
| 2026-08-18 00:00 |
16:04:16.19 |
+24:15:19.9 |
HIP 78673 |
8.86 |
| 2026-08-18 12:00 |
16:04:15.70 |
+24:14:02.6 |
HIP 78673 |
8.41 |
| 2026-08-19 00:00 |
16:04:15.26 |
+24:12:45.2 |
HIP 78673 |
8.14 |