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) |
| 2026-06-01 00:00 |
16:15:46.41 |
+26:25:05.0 |
HIP 79683 |
41.61 |
| 2026-06-01 12:00 |
16:15:39.40 |
+26:24:56.7 |
HIP 79683 |
41.49 |
| 2026-06-02 00:00 |
16:15:32.40 |
+26:24:47.8 |
HIP 79441 |
40.41 |
| 2026-06-02 12:00 |
16:15:25.40 |
+26:24:38.2 |
HIP 79441 |
39.03 |
| 2026-06-03 00:00 |
16:15:18.42 |
+26:24:28.0 |
HIP 79441 |
37.68 |
| 2026-06-03 12:00 |
16:15:11.44 |
+26:24:17.1 |
HIP 79441 |
36.35 |
| 2026-06-04 00:00 |
16:15:04.48 |
+26:24:05.6 |
HIP 79441 |
35.04 |
| 2026-06-04 12:00 |
16:14:57.53 |
+26:23:53.4 |
HIP 79441 |
33.77 |
| 2026-06-05 00:00 |
16:14:50.59 |
+26:23:40.6 |
HIP 79441 |
32.53 |
| 2026-06-05 12:00 |
16:14:43.66 |
+26:23:27.2 |
HIP 79413 |
31.11 |
| 2026-06-06 00:00 |
16:14:36.75 |
+26:23:13.1 |
HIP 79413 |
29.59 |
| 2026-06-06 12:00 |
16:14:29.85 |
+26:22:58.3 |
HIP 79413 |
28.07 |
| 2026-06-07 00:00 |
16:14:22.96 |
+26:22:42.9 |
HIP 79413 |
26.57 |
| 2026-06-07 12:00 |
16:14:16.09 |
+26:22:26.9 |
HIP 79413 |
25.08 |
| 2026-06-08 00:00 |
16:14:09.24 |
+26:22:10.2 |
HIP 79413 |
23.60 |
| 2026-06-08 12:00 |
16:14:02.40 |
+26:21:52.9 |
HIP 79413 |
22.14 |
| 2026-06-09 00:00 |
16:13:55.57 |
+26:21:34.9 |
HIP 79413 |
20.70 |
| 2026-06-09 12:00 |
16:13:48.77 |
+26:21:16.3 |
HIP 79413 |
19.29 |
| 2026-06-10 00:00 |
16:13:41.98 |
+26:20:57.1 |
HIP 79413 |
17.90 |
| 2026-06-10 12:00 |
16:13:35.21 |
+26:20:37.2 |
HIP 79413 |
16.55 |
| 2026-06-11 00:00 |
16:13:28.46 |
+26:20:16.7 |
HIP 79413 |
15.25 |
| 2026-06-11 12:00 |
16:13:21.73 |
+26:19:55.5 |
HIP 79413 |
14.00 |
| 2026-06-12 00:00 |
16:13:15.02 |
+26:19:33.7 |
HIP 79413 |
12.84 |
| 2026-06-12 12:00 |
16:13:08.33 |
+26:19:11.3 |
HIP 79413 |
11.76 |
| 2026-06-13 00:00 |
16:13:01.66 |
+26:18:48.3 |
HIP 79413 |
10.82 |
| 2026-06-13 12:00 |
16:12:55.02 |
+26:18:24.6 |
HIP 79413 |
10.03 |
| 2026-06-14 00:00 |
16:12:48.39 |
+26:18:00.2 |
HIP 79413 |
9.45 |
| 2026-06-14 12:00 |
16:12:41.79 |
+26:17:35.3 |
HIP 79413 |
9.10 |
| 2026-06-15 00:00 |
16:12:35.22 |
+26:17:09.7 |
HIP 79413 |
9.01 |
| 2026-06-15 12:00 |
16:12:28.67 |
+26:16:43.5 |
HIP 79413 |
9.19 |
| 2026-06-16 00:00 |
16:12:22.14 |
+26:16:16.6 |
HIP 79413 |
9.63 |
| 2026-06-16 12:00 |
16:12:15.64 |
+26:15:49.2 |
HIP 79413 |
10.29 |
| 2026-06-17 00:00 |
16:12:09.16 |
+26:15:21.1 |
HIP 79413 |
11.13 |
| 2026-06-17 12:00 |
16:12:02.71 |
+26:14:52.4 |
HIP 79413 |
12.11 |
| 2026-06-18 00:00 |
16:11:56.29 |
+26:14:23.1 |
HIP 79413 |
13.19 |
| 2026-06-18 12:00 |
16:11:49.90 |
+26:13:53.2 |
HIP 79413 |
14.37 |
| 2026-06-19 00:00 |
16:11:43.53 |
+26:13:22.6 |
HIP 79291 |
14.79 |
| 2026-06-19 12:00 |
16:11:37.19 |
+26:12:51.5 |
HIP 79291 |
14.23 |
| 2026-06-20 00:00 |
16:11:30.89 |
+26:12:19.7 |
HIP 79291 |
13.83 |
| 2026-06-20 12:00 |
16:11:24.61 |
+26:11:47.4 |
HIP 79291 |
13.59 |
| 2026-06-21 00:00 |
16:11:18.36 |
+26:11:14.4 |
HIP 79291 |
13.53 |
| 2026-06-21 12:00 |
16:11:12.14 |
+26:10:40.9 |
HIP 79291 |
13.65 |
| 2026-06-22 00:00 |
16:11:05.96 |
+26:10:06.8 |
HIP 79291 |
13.94 |