メタデータ
| 項目 |
値 |
| Designation |
C/1989 X1 (Austin) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1990-04-09T23:13:18.471360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:38Z |
| Obs used |
266 |
| NEO |
- |
| M1 |
8.400 |
| K1 |
13.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1990-04-17.0000000 |
| e |
1.00022808 |
| q (au) |
0.349774 |
| a (au) |
-1533.545418 |
| i (deg) |
58.956368 |
| Ω (om, deg) |
75.925356 |
| ω (w, deg) |
61.576294 |
| M (ma, deg) |
0.000115 |
等級
散乱 + 全体線形
$$
M_a = (8.064 + 3.044\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.064 |
| n |
3.044 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
1.585 |
| 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 |
| 1989-12-06 |
1990-02-07 |
+5.2737 |
-3.494 |
| 1990-02-07 |
1990-04-09 |
-4.1988 |
-2.041 |
| 1990-04-10 |
1990-05-13 |
-0.8424 |
-0.129 |
| 1990-05-13 |
1990-07-24 |
+4.3633 |
+0.116 |
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) |
| 2026-06-01 00:00 |
20:27:48.86 |
-64:19:10.2 |
HIP 101064 |
10.63 |
| 2026-06-01 12:00 |
20:27:46.42 |
-64:19:29.9 |
HIP 101064 |
10.74 |
| 2026-06-02 00:00 |
20:27:43.94 |
-64:19:49.5 |
HIP 101064 |
10.87 |
| 2026-06-02 12:00 |
20:27:41.44 |
-64:20:09.0 |
HIP 101064 |
11.01 |
| 2026-06-03 00:00 |
20:27:38.90 |
-64:20:28.4 |
HIP 101064 |
11.17 |
| 2026-06-03 12:00 |
20:27:36.34 |
-64:20:47.7 |
HIP 101064 |
11.35 |
| 2026-06-04 00:00 |
20:27:33.75 |
-64:21:07.0 |
HIP 101064 |
11.55 |
| 2026-06-04 12:00 |
20:27:31.12 |
-64:21:26.2 |
HIP 101064 |
11.76 |
| 2026-06-05 00:00 |
20:27:28.47 |
-64:21:45.4 |
HIP 101064 |
11.99 |
| 2026-06-05 12:00 |
20:27:25.79 |
-64:22:04.4 |
HIP 101064 |
12.23 |
| 2026-06-06 00:00 |
20:27:23.07 |
-64:22:23.4 |
HIP 101064 |
12.48 |
| 2026-06-06 12:00 |
20:27:20.33 |
-64:22:42.3 |
HIP 101064 |
12.75 |
| 2026-06-07 00:00 |
20:27:17.56 |
-64:23:01.1 |
HIP 101064 |
13.03 |
| 2026-06-07 12:00 |
20:27:14.76 |
-64:23:19.8 |
HIP 101064 |
13.32 |
| 2026-06-08 00:00 |
20:27:11.94 |
-64:23:38.4 |
HIP 101064 |
13.62 |
| 2026-06-08 12:00 |
20:27:09.08 |
-64:23:57.0 |
HIP 101064 |
13.93 |
| 2026-06-09 00:00 |
20:27:06.20 |
-64:24:15.4 |
HIP 100717 |
14.18 |
| 2026-06-09 12:00 |
20:27:03.29 |
-64:24:33.8 |
HIP 100717 |
14.04 |
| 2026-06-10 00:00 |
20:27:00.35 |
-64:24:52.1 |
HIP 100717 |
13.90 |
| 2026-06-10 12:00 |
20:26:57.38 |
-64:25:10.2 |
HIP 100717 |
13.78 |
| 2026-06-11 00:00 |
20:26:54.38 |
-64:25:28.3 |
HIP 100717 |
13.66 |
| 2026-06-11 12:00 |
20:26:51.36 |
-64:25:46.3 |
HIP 100717 |
13.56 |
| 2026-06-12 00:00 |
20:26:48.31 |
-64:26:04.2 |
HIP 100717 |
13.47 |
| 2026-06-12 12:00 |
20:26:45.24 |
-64:26:22.0 |
HIP 100717 |
13.38 |
| 2026-06-13 00:00 |
20:26:42.13 |
-64:26:39.6 |
HIP 100717 |
13.31 |
| 2026-06-13 12:00 |
20:26:39.01 |
-64:26:57.2 |
HIP 100717 |
13.25 |
| 2026-06-14 00:00 |
20:26:35.85 |
-64:27:14.7 |
HIP 100717 |
13.20 |
| 2026-06-14 12:00 |
20:26:32.67 |
-64:27:32.1 |
HIP 100717 |
13.17 |
| 2026-06-15 00:00 |
20:26:29.46 |
-64:27:49.3 |
HIP 100717 |
13.14 |
| 2026-06-15 12:00 |
20:26:26.23 |
-64:28:06.5 |
HIP 100717 |
13.13 |
| 2026-06-16 00:00 |
20:26:22.98 |
-64:28:23.5 |
HIP 100717 |
13.13 |
| 2026-06-16 12:00 |
20:26:19.69 |
-64:28:40.5 |
HIP 100717 |
13.14 |
| 2026-06-17 00:00 |
20:26:16.39 |
-64:28:57.3 |
HIP 100717 |
13.17 |
| 2026-06-17 12:00 |
20:26:13.06 |
-64:29:14.0 |
HIP 100717 |
13.21 |
| 2026-06-18 00:00 |
20:26:09.71 |
-64:29:30.6 |
HIP 100717 |
13.26 |
| 2026-06-18 12:00 |
20:26:06.33 |
-64:29:47.0 |
HIP 100717 |
13.32 |
| 2026-06-19 00:00 |
20:26:02.93 |
-64:30:03.4 |
HIP 100717 |
13.40 |
| 2026-06-19 12:00 |
20:25:59.50 |
-64:30:19.6 |
HIP 100614 |
13.12 |
| 2026-06-20 00:00 |
20:25:56.05 |
-64:30:35.7 |
HIP 100614 |
12.67 |
| 2026-06-20 12:00 |
20:25:52.59 |
-64:30:51.7 |
HIP 100614 |
12.22 |
| 2026-06-21 00:00 |
20:25:49.09 |
-64:31:07.6 |
HIP 100614 |
11.78 |
| 2026-06-21 12:00 |
20:25:45.58 |
-64:31:23.3 |
HIP 100614 |
11.33 |
| 2026-06-22 00:00 |
20:25:42.04 |
-64:31:38.9 |
HIP 100614 |
10.88 |