C/2018 V1 (Machholz-Fujikawa-Iwamoto)
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
$$
M_a = (12.884 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.884 |
| 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 |
-2.0658 |
-0.722 |
| 2018-11-17 |
2018-12-01 |
+3.0754 |
+1.824 |
| 2018-12-04 |
2018-12-17 |
+11.8201 |
+5.114 |
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) |
| 2026-02-03 00:00 |
15:20:18.80 |
-53:24:06.6 |
HIP 75173 |
14.74 |
| 2026-02-03 12:00 |
15:20:19.71 |
-53:24:58.0 |
HIP 75173 |
14.16 |
| 2026-02-04 00:00 |
15:20:20.54 |
-53:25:49.4 |
HIP 75173 |
13.61 |
| 2026-02-04 12:00 |
15:20:21.29 |
-53:26:40.6 |
HIP 75173 |
13.12 |
| 2026-02-05 00:00 |
15:20:21.96 |
-53:27:31.8 |
HIP 75173 |
12.67 |
| 2026-02-05 12:00 |
15:20:22.55 |
-53:28:22.9 |
HIP 75173 |
12.28 |
| 2026-02-06 00:00 |
15:20:23.06 |
-53:29:13.9 |
HIP 75173 |
11.95 |
| 2026-02-06 12:00 |
15:20:23.49 |
-53:30:04.8 |
HIP 75173 |
11.68 |
| 2026-02-07 00:00 |
15:20:23.84 |
-53:30:55.6 |
HIP 75173 |
11.49 |
| 2026-02-07 12:00 |
15:20:24.10 |
-53:31:46.4 |
HIP 75173 |
11.36 |
| 2026-02-08 00:00 |
15:20:24.29 |
-53:32:37.0 |
HIP 75173 |
11.32 |
| 2026-02-08 12:00 |
15:20:24.39 |
-53:33:27.5 |
HIP 75173 |
11.34 |
| 2026-02-09 00:00 |
15:20:24.41 |
-53:34:17.9 |
HIP 75173 |
11.44 |
| 2026-02-09 12:00 |
15:20:24.35 |
-53:35:08.2 |
HIP 75173 |
11.61 |
| 2026-02-10 00:00 |
15:20:24.21 |
-53:35:58.4 |
HIP 75173 |
11.85 |
| 2026-02-10 12:00 |
15:20:23.99 |
-53:36:48.4 |
HIP 75173 |
12.15 |
| 2026-02-11 00:00 |
15:20:23.68 |
-53:37:38.3 |
HIP 75173 |
12.52 |
| 2026-02-11 12:00 |
15:20:23.29 |
-53:38:28.1 |
HIP 75173 |
12.93 |
| 2026-02-12 00:00 |
15:20:22.82 |
-53:39:17.8 |
HIP 75173 |
13.39 |
| 2026-02-12 12:00 |
15:20:22.27 |
-53:40:07.3 |
HIP 75173 |
13.90 |
| 2026-02-13 00:00 |
15:20:21.63 |
-53:40:56.7 |
HIP 75173 |
14.45 |
| 2026-02-13 12:00 |
15:20:20.91 |
-53:41:45.9 |
HIP 75173 |
15.02 |
| 2026-02-14 00:00 |
15:20:20.10 |
-53:42:35.0 |
HIP 75173 |
15.63 |
| 2026-02-14 12:00 |
15:20:19.21 |
-53:43:23.9 |
HIP 75173 |
16.27 |
| 2026-02-15 00:00 |
15:20:18.24 |
-53:44:12.7 |
HIP 75173 |
16.93 |
| 2026-02-15 12:00 |
15:20:17.19 |
-53:45:01.3 |
HIP 75173 |
17.61 |
| 2026-02-16 00:00 |
15:20:16.05 |
-53:45:49.8 |
HIP 75173 |
18.31 |
| 2026-02-16 12:00 |
15:20:14.82 |
-53:46:38.0 |
HIP 75173 |
19.02 |
| 2026-02-17 00:00 |
15:20:13.52 |
-53:47:26.1 |
HIP 75173 |
19.75 |
| 2026-02-17 12:00 |
15:20:12.13 |
-53:48:14.0 |
HIP 75173 |
20.49 |
| 2026-02-18 00:00 |
15:20:10.65 |
-53:49:01.8 |
HIP 75173 |
21.25 |
| 2026-02-18 12:00 |
15:20:09.09 |
-53:49:49.3 |
HIP 75173 |
22.01 |
| 2026-02-19 00:00 |
15:20:07.45 |
-53:50:36.7 |
HIP 75173 |
22.78 |
| 2026-02-19 12:00 |
15:20:05.72 |
-53:51:23.8 |
HIP 75173 |
23.56 |
| 2026-02-20 00:00 |
15:20:03.91 |
-53:52:10.8 |
HIP 75173 |
24.35 |
| 2026-02-20 12:00 |
15:20:02.01 |
-53:52:57.5 |
HIP 75173 |
25.15 |
| 2026-02-21 00:00 |
15:20:00.03 |
-53:53:44.1 |
HIP 75173 |
25.95 |
| 2026-02-21 12:00 |
15:19:57.97 |
-53:54:30.4 |
HIP 75134 |
25.48 |
| 2026-02-22 00:00 |
15:19:55.82 |
-53:55:16.5 |
HIP 75134 |
24.93 |
| 2026-02-22 12:00 |
15:19:53.59 |
-53:56:02.4 |
HIP 75134 |
24.40 |
| 2026-02-23 00:00 |
15:19:51.28 |
-53:56:48.1 |
HIP 75134 |
23.90 |
| 2026-02-23 12:00 |
15:19:48.88 |
-53:57:33.5 |
HIP 75134 |
23.43 |
| 2026-02-24 00:00 |
15:19:46.40 |
-53:58:18.7 |
HIP 75134 |
22.99 |