メタデータ
| 項目 |
値 |
| Designation |
C/2018 V1 (Machholz-Fujikawa-Iwamoto) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-12-03T12:11:39.986880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:46Z |
| Obs used |
750 |
| NEO |
- |
| M1 |
12.800 |
| K1 |
6.250 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-11-16.0000000 |
| e |
1.00039061 |
| q (au) |
0.386955 |
| a (au) |
-990.650949 |
| i (deg) |
143.987960 |
| Ω (om, deg) |
128.722091 |
| ω (w, deg) |
88.774914 |
| M (ma, deg) |
-0.000553 |
等級
散乱 + 全体線形
$$
M_a = (12.888 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.888 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
0.800 |
| δ90 |
1.000 |
| 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 |
| 2018-11-08 |
2018-11-17 |
-1.9894 |
-0.711 |
| 2018-11-17 |
2018-12-01 |
+3.0505 |
+1.813 |
| 2018-12-04 |
2018-12-17 |
+11.8201 |
+5.111 |
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) |
| 2026-05-12 00:00 |
15:00:31.97 |
-54:35:53.7 |
HIP 73391 |
18.63 |
| 2026-05-12 12:00 |
15:00:22.00 |
-54:35:30.5 |
HIP 73391 |
17.87 |
| 2026-05-13 00:00 |
15:00:12.03 |
-54:35:06.8 |
HIP 73391 |
17.20 |
| 2026-05-13 12:00 |
15:00:02.08 |
-54:34:42.6 |
HIP 73391 |
16.63 |
| 2026-05-14 00:00 |
14:59:52.14 |
-54:34:17.9 |
HIP 73391 |
16.18 |
| 2026-05-14 12:00 |
14:59:42.21 |
-54:33:52.8 |
HIP 73391 |
15.84 |
| 2026-05-15 00:00 |
14:59:32.29 |
-54:33:27.2 |
HIP 73391 |
15.63 |
| 2026-05-15 12:00 |
14:59:22.39 |
-54:33:01.1 |
HIP 73391 |
15.56 |
| 2026-05-16 00:00 |
14:59:12.50 |
-54:32:34.5 |
HIP 73391 |
15.63 |
| 2026-05-16 12:00 |
14:59:02.63 |
-54:32:07.5 |
HIP 73391 |
15.83 |
| 2026-05-17 00:00 |
14:58:52.77 |
-54:31:40.0 |
HIP 73391 |
16.17 |
| 2026-05-17 12:00 |
14:58:42.93 |
-54:31:12.0 |
HIP 73391 |
16.62 |
| 2026-05-18 00:00 |
14:58:33.12 |
-54:30:43.5 |
HIP 73391 |
17.19 |
| 2026-05-18 12:00 |
14:58:23.32 |
-54:30:14.6 |
HIP 73391 |
17.86 |
| 2026-05-19 00:00 |
14:58:13.54 |
-54:29:45.3 |
HIP 73391 |
18.62 |
| 2026-05-19 12:00 |
14:58:03.79 |
-54:29:15.5 |
HIP 73391 |
19.46 |
| 2026-05-20 00:00 |
14:57:54.05 |
-54:28:45.2 |
HIP 73391 |
20.38 |
| 2026-05-20 12:00 |
14:57:44.34 |
-54:28:14.5 |
HIP 73391 |
21.35 |
| 2026-05-21 00:00 |
14:57:34.66 |
-54:27:43.3 |
HIP 73391 |
22.38 |
| 2026-05-21 12:00 |
14:57:24.99 |
-54:27:11.8 |
HIP 73391 |
23.45 |
| 2026-05-22 00:00 |
14:57:15.36 |
-54:26:39.7 |
HIP 73391 |
24.56 |
| 2026-05-22 12:00 |
14:57:05.75 |
-54:26:07.3 |
HIP 73391 |
25.70 |
| 2026-05-23 00:00 |
14:56:56.17 |
-54:25:34.4 |
HIP 73391 |
26.88 |
| 2026-05-23 12:00 |
14:56:46.61 |
-54:25:01.1 |
HIP 73391 |
28.08 |
| 2026-05-24 00:00 |
14:56:37.09 |
-54:24:27.3 |
HIP 73391 |
29.30 |
| 2026-05-24 12:00 |
14:56:27.59 |
-54:23:53.2 |
HIP 73391 |
30.55 |
| 2026-05-25 00:00 |
14:56:18.13 |
-54:23:18.6 |
HIP 73391 |
31.81 |
| 2026-05-25 12:00 |
14:56:08.70 |
-54:22:43.6 |
HIP 73391 |
33.08 |
| 2026-05-26 00:00 |
14:55:59.29 |
-54:22:08.2 |
HIP 73391 |
34.37 |
| 2026-05-26 12:00 |
14:55:49.92 |
-54:21:32.4 |
HIP 72746 |
35.29 |
| 2026-05-27 00:00 |
14:55:40.59 |
-54:20:56.2 |
HIP 72746 |
34.45 |
| 2026-05-27 12:00 |
14:55:31.29 |
-54:20:19.6 |
HIP 72746 |
33.66 |
| 2026-05-28 00:00 |
14:55:22.02 |
-54:19:42.6 |
HIP 72746 |
32.93 |
| 2026-05-28 12:00 |
14:55:12.79 |
-54:19:05.2 |
HIP 72746 |
32.25 |
| 2026-05-29 00:00 |
14:55:03.59 |
-54:18:27.4 |
HIP 72746 |
31.64 |
| 2026-05-29 12:00 |
14:54:54.43 |
-54:17:49.2 |
HIP 72746 |
31.10 |
| 2026-05-30 00:00 |
14:54:45.31 |
-54:17:10.7 |
HIP 72746 |
30.62 |
| 2026-05-30 12:00 |
14:54:36.23 |
-54:16:31.8 |
HIP 72746 |
30.22 |
| 2026-05-31 00:00 |
14:54:27.18 |
-54:15:52.5 |
HIP 72746 |
29.89 |
| 2026-05-31 12:00 |
14:54:18.18 |
-54:15:12.8 |
HIP 72746 |
29.64 |
| 2026-06-01 00:00 |
14:54:09.21 |
-54:14:32.8 |
HIP 72746 |
29.46 |
| 2026-06-01 12:00 |
14:54:00.28 |
-54:13:52.4 |
HIP 72746 |
29.37 |
| 2026-06-02 00:00 |
14:53:51.40 |
-54:13:11.6 |
HIP 72746 |
29.36 |