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) |
| 2026-03-26 00:00 |
15:14:51.56 |
-54:34:09.0 |
HIP 74546 |
8.80 |
| 2026-03-26 12:00 |
15:14:44.40 |
-54:34:33.2 |
HIP 74546 |
7.69 |
| 2026-03-27 00:00 |
15:14:37.18 |
-54:34:57.0 |
HIP 74546 |
6.58 |
| 2026-03-27 12:00 |
15:14:29.89 |
-54:35:20.3 |
HIP 74546 |
5.46 |
| 2026-03-28 00:00 |
15:14:22.55 |
-54:35:43.2 |
HIP 74546 |
4.34 |
| 2026-03-28 12:00 |
15:14:15.13 |
-54:36:05.6 |
HIP 74546 |
3.22 |
| 2026-03-29 00:00 |
15:14:07.66 |
-54:36:27.6 |
HIP 74546 |
2.13 |
| 2026-03-29 12:00 |
15:14:00.13 |
-54:36:49.1 |
HIP 74546 |
1.14 |
| 2026-03-30 00:00 |
15:13:52.53 |
-54:37:10.1 |
HIP 74546 |
0.85 |
| 2026-03-30 12:00 |
15:13:44.88 |
-54:37:30.7 |
HIP 74546 |
1.68 |
| 2026-03-31 00:00 |
15:13:37.17 |
-54:37:50.8 |
HIP 74546 |
2.77 |
| 2026-03-31 12:00 |
15:13:29.39 |
-54:38:10.5 |
HIP 74546 |
3.91 |
| 2026-04-01 00:00 |
15:13:21.56 |
-54:38:29.6 |
HIP 74546 |
5.07 |
| 2026-04-01 12:00 |
15:13:13.68 |
-54:38:48.4 |
HIP 74546 |
6.25 |
| 2026-04-02 00:00 |
15:13:05.73 |
-54:39:06.6 |
HIP 74448 |
6.63 |
| 2026-04-02 12:00 |
15:12:57.73 |
-54:39:24.3 |
HIP 74448 |
6.03 |
| 2026-04-03 00:00 |
15:12:49.68 |
-54:39:41.6 |
HIP 74448 |
5.62 |
| 2026-04-03 12:00 |
15:12:41.56 |
-54:39:58.4 |
HIP 74448 |
5.46 |
| 2026-04-04 00:00 |
15:12:33.40 |
-54:40:14.7 |
HIP 74448 |
5.58 |
| 2026-04-04 12:00 |
15:12:25.18 |
-54:40:30.6 |
HIP 74448 |
5.95 |
| 2026-04-05 00:00 |
15:12:16.91 |
-54:40:45.9 |
HIP 74448 |
6.55 |
| 2026-04-05 12:00 |
15:12:08.58 |
-54:41:00.8 |
HIP 74448 |
7.31 |
| 2026-04-06 00:00 |
15:12:00.20 |
-54:41:15.1 |
HIP 74448 |
8.20 |
| 2026-04-06 12:00 |
15:11:51.78 |
-54:41:29.0 |
HIP 74448 |
9.18 |
| 2026-04-07 00:00 |
15:11:43.30 |
-54:41:42.4 |
HIP 74448 |
10.22 |
| 2026-04-07 12:00 |
15:11:34.77 |
-54:41:55.3 |
HIP 74448 |
11.31 |
| 2026-04-08 00:00 |
15:11:26.19 |
-54:42:07.7 |
HIP 74448 |
12.44 |
| 2026-04-08 12:00 |
15:11:17.57 |
-54:42:19.6 |
HIP 74448 |
13.61 |
| 2026-04-09 00:00 |
15:11:08.89 |
-54:42:30.9 |
HIP 74448 |
14.79 |
| 2026-04-09 12:00 |
15:11:00.17 |
-54:42:41.8 |
HIP 74448 |
16.00 |
| 2026-04-10 00:00 |
15:10:51.41 |
-54:42:52.2 |
HIP 74448 |
17.22 |
| 2026-04-10 12:00 |
15:10:42.59 |
-54:43:02.1 |
HIP 74448 |
18.46 |
| 2026-04-11 00:00 |
15:10:33.74 |
-54:43:11.4 |
HIP 74152 |
17.74 |
| 2026-04-11 12:00 |
15:10:24.84 |
-54:43:20.3 |
HIP 74152 |
16.74 |
| 2026-04-12 00:00 |
15:10:15.89 |
-54:43:28.6 |
HIP 74152 |
15.79 |
| 2026-04-12 12:00 |
15:10:06.90 |
-54:43:36.4 |
HIP 74152 |
14.88 |
| 2026-04-13 00:00 |
15:09:57.87 |
-54:43:43.7 |
HIP 74152 |
14.05 |
| 2026-04-13 12:00 |
15:09:48.80 |
-54:43:50.5 |
HIP 74152 |
13.30 |
| 2026-04-14 00:00 |
15:09:39.69 |
-54:43:56.8 |
HIP 74152 |
12.64 |
| 2026-04-14 12:00 |
15:09:30.54 |
-54:44:02.6 |
HIP 74152 |
12.10 |
| 2026-04-15 00:00 |
15:09:21.36 |
-54:44:07.8 |
HIP 74152 |
11.69 |
| 2026-04-15 12:00 |
15:09:12.13 |
-54:44:12.5 |
HIP 74152 |
11.43 |
| 2026-04-16 00:00 |
15:09:02.87 |
-54:44:16.7 |
HIP 74152 |
11.33 |