C/2018 A6 (Gibbs)
メタデータ
| 項目 |
値 |
| Designation |
C/2018 A6 (Gibbs) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-07-14T07:12:03.481920Z |
| Orbit solution date (soln_date, UTC) |
2024-05-30T01:12:17Z |
| Obs used |
915 |
| NEO |
- |
| M1 |
9.700 |
| K1 |
7.250 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2019-12-10.0000000 |
| e |
0.80342745 |
| q (au) |
3.017827 |
| a (au) |
15.352231 |
| i (deg) |
76.954875 |
| Ω (om, deg) |
340.386138 |
| ω (w, deg) |
264.536453 |
| M (ma, deg) |
2.436451 |
等級
散乱 + 全体線形
$$
M_a = (6.874 + 3.973\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
6.874 |
| n |
3.973 |
| gf |
1.000 |
| gb |
-0.502 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2017-04-03 |
2018-02-13 |
-4.4374 |
+4.270 |
| 2018-02-13 |
2019-07-08 |
+5.4711 |
-3.199 |
| 2019-07-20 |
2020-06-07 |
+11.2381 |
-6.514 |
| 2020-06-07 |
2021-10-03 |
-7.5580 |
+5.191 |
| 2021-10-03 |
2023-10-19 |
-7.6929 |
+5.633 |
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 |
22:09:27.31 |
+33:46:38.0 |
HIP 109234 |
30.31 |
| 2026-02-03 12:00 |
22:09:35.73 |
+33:47:02.6 |
HIP 109234 |
31.84 |
| 2026-02-04 00:00 |
22:09:44.17 |
+33:47:27.8 |
HIP 109234 |
33.41 |
| 2026-02-04 12:00 |
22:09:52.63 |
+33:47:53.8 |
HIP 109234 |
35.01 |
| 2026-02-05 00:00 |
22:10:01.10 |
+33:48:20.5 |
HIP 109234 |
36.65 |
| 2026-02-05 12:00 |
22:10:09.59 |
+33:48:48.0 |
HIP 109255 |
38.01 |
| 2026-02-06 00:00 |
22:10:18.09 |
+33:49:16.1 |
HIP 109677 |
36.75 |
| 2026-02-06 12:00 |
22:10:26.61 |
+33:49:45.0 |
HIP 109677 |
35.28 |
| 2026-02-07 00:00 |
22:10:35.14 |
+33:50:14.7 |
HIP 109677 |
33.85 |
| 2026-02-07 12:00 |
22:10:43.68 |
+33:50:45.0 |
HIP 109677 |
32.47 |
| 2026-02-08 00:00 |
22:10:52.24 |
+33:51:16.1 |
HIP 109677 |
31.13 |
| 2026-02-08 12:00 |
22:11:00.81 |
+33:51:47.9 |
HIP 109677 |
29.86 |
| 2026-02-09 00:00 |
22:11:09.39 |
+33:52:20.5 |
HIP 109677 |
28.65 |
| 2026-02-09 12:00 |
22:11:17.98 |
+33:52:53.7 |
HIP 109677 |
27.53 |
| 2026-02-10 00:00 |
22:11:26.58 |
+33:53:27.7 |
HIP 109677 |
26.49 |
| 2026-02-10 12:00 |
22:11:35.19 |
+33:54:02.4 |
HIP 109677 |
25.56 |
| 2026-02-11 00:00 |
22:11:43.82 |
+33:54:37.8 |
HIP 109677 |
24.75 |
| 2026-02-11 12:00 |
22:11:52.45 |
+33:55:14.0 |
HIP 109677 |
24.06 |
| 2026-02-12 00:00 |
22:12:01.09 |
+33:55:50.8 |
HIP 109677 |
23.52 |
| 2026-02-12 12:00 |
22:12:09.73 |
+33:56:28.4 |
HIP 109677 |
23.13 |
| 2026-02-13 00:00 |
22:12:18.39 |
+33:57:06.7 |
HIP 109677 |
22.90 |
| 2026-02-13 12:00 |
22:12:27.05 |
+33:57:45.7 |
HIP 109677 |
22.84 |
| 2026-02-14 00:00 |
22:12:35.72 |
+33:58:25.3 |
HIP 109677 |
22.95 |
| 2026-02-14 12:00 |
22:12:44.39 |
+33:59:05.7 |
HIP 109677 |
23.24 |
| 2026-02-15 00:00 |
22:12:53.07 |
+33:59:46.8 |
HIP 109677 |
23.68 |
| 2026-02-15 12:00 |
22:13:01.75 |
+34:00:28.6 |
HIP 109677 |
24.29 |
| 2026-02-16 00:00 |
22:13:10.44 |
+34:01:11.2 |
HIP 109676 |
24.23 |
| 2026-02-16 12:00 |
22:13:19.13 |
+34:01:54.4 |
HIP 109676 |
23.69 |
| 2026-02-17 00:00 |
22:13:27.82 |
+34:02:38.2 |
HIP 109877 |
22.64 |
| 2026-02-17 12:00 |
22:13:36.51 |
+34:03:22.8 |
HIP 109877 |
20.94 |
| 2026-02-18 00:00 |
22:13:45.21 |
+34:04:08.1 |
HIP 109877 |
19.28 |
| 2026-02-18 12:00 |
22:13:53.90 |
+34:04:54.1 |
HIP 109877 |
17.69 |
| 2026-02-19 00:00 |
22:14:02.60 |
+34:05:40.7 |
HIP 109877 |
16.18 |
| 2026-02-19 12:00 |
22:14:11.30 |
+34:06:28.1 |
HIP 109877 |
14.78 |
| 2026-02-20 00:00 |
22:14:19.99 |
+34:07:16.1 |
HIP 109877 |
13.54 |
| 2026-02-20 12:00 |
22:14:28.69 |
+34:08:04.8 |
HIP 109877 |
12.49 |
| 2026-02-21 00:00 |
22:14:37.38 |
+34:08:54.2 |
HIP 109877 |
11.69 |
| 2026-02-21 12:00 |
22:14:46.07 |
+34:09:44.2 |
HIP 109877 |
11.19 |
| 2026-02-22 00:00 |
22:14:54.76 |
+34:10:34.9 |
HIP 109877 |
11.05 |
| 2026-02-22 12:00 |
22:15:03.44 |
+34:11:26.3 |
HIP 109877 |
11.27 |
| 2026-02-23 00:00 |
22:15:12.12 |
+34:12:18.3 |
HIP 109877 |
11.84 |
| 2026-02-23 12:00 |
22:15:20.79 |
+34:13:11.0 |
HIP 109877 |
12.71 |
| 2026-02-24 00:00 |
22:15:29.46 |
+34:14:04.3 |
HIP 109877 |
13.83 |