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) |
| 2026-09-20 00:00 |
20:14:18.19 |
-64:33:46.6 |
HIP 99772 |
8.19 |
| 2026-09-20 12:00 |
20:14:15.85 |
-64:33:32.3 |
HIP 99772 |
8.02 |
| 2026-09-21 00:00 |
20:14:13.54 |
-64:33:17.9 |
HIP 99772 |
7.86 |
| 2026-09-21 12:00 |
20:14:11.26 |
-64:33:03.4 |
HIP 99772 |
7.71 |
| 2026-09-22 00:00 |
20:14:09.02 |
-64:32:48.7 |
HIP 99772 |
7.56 |
| 2026-09-22 12:00 |
20:14:06.80 |
-64:32:33.9 |
HIP 99772 |
7.43 |
| 2026-09-23 00:00 |
20:14:04.63 |
-64:32:19.0 |
HIP 99772 |
7.30 |
| 2026-09-23 12:00 |
20:14:02.48 |
-64:32:04.0 |
HIP 99772 |
7.19 |
| 2026-09-24 00:00 |
20:14:00.37 |
-64:31:48.9 |
HIP 99772 |
7.09 |
| 2026-09-24 12:00 |
20:13:58.29 |
-64:31:33.6 |
HIP 99772 |
7.00 |
| 2026-09-25 00:00 |
20:13:56.24 |
-64:31:18.2 |
HIP 99772 |
6.92 |
| 2026-09-25 12:00 |
20:13:54.23 |
-64:31:02.7 |
HIP 99772 |
6.85 |
| 2026-09-26 00:00 |
20:13:52.25 |
-64:30:47.1 |
HIP 99772 |
6.79 |
| 2026-09-26 12:00 |
20:13:50.30 |
-64:30:31.4 |
HIP 99772 |
6.75 |
| 2026-09-27 00:00 |
20:13:48.39 |
-64:30:15.5 |
HIP 99772 |
6.72 |
| 2026-09-27 12:00 |
20:13:46.51 |
-64:29:59.6 |
HIP 99772 |
6.70 |
| 2026-09-28 00:00 |
20:13:44.67 |
-64:29:43.5 |
HIP 99772 |
6.70 |
| 2026-09-28 12:00 |
20:13:42.86 |
-64:29:27.4 |
HIP 99772 |
6.71 |
| 2026-09-29 00:00 |
20:13:41.09 |
-64:29:11.1 |
HIP 99772 |
6.73 |
| 2026-09-29 12:00 |
20:13:39.34 |
-64:28:54.7 |
HIP 99772 |
6.76 |
| 2026-09-30 00:00 |
20:13:37.64 |
-64:28:38.2 |
HIP 99772 |
6.80 |
| 2026-09-30 12:00 |
20:13:35.97 |
-64:28:21.6 |
HIP 99772 |
6.86 |
| 2026-10-01 00:00 |
20:13:34.33 |
-64:28:04.9 |
HIP 99772 |
6.93 |
| 2026-10-01 12:00 |
20:13:32.73 |
-64:27:48.1 |
HIP 99772 |
7.00 |
| 2026-10-02 00:00 |
20:13:31.16 |
-64:27:31.2 |
HIP 99772 |
7.09 |
| 2026-10-02 12:00 |
20:13:29.63 |
-64:27:14.2 |
HIP 99772 |
7.19 |
| 2026-10-03 00:00 |
20:13:28.14 |
-64:26:57.1 |
HIP 99772 |
7.30 |
| 2026-10-03 12:00 |
20:13:26.68 |
-64:26:39.9 |
HIP 99772 |
7.41 |
| 2026-10-04 00:00 |
20:13:25.25 |
-64:26:22.6 |
HIP 99772 |
7.54 |
| 2026-10-04 12:00 |
20:13:23.86 |
-64:26:05.2 |
HIP 99772 |
7.67 |
| 2026-10-05 00:00 |
20:13:22.51 |
-64:25:47.7 |
HIP 99772 |
7.81 |
| 2026-10-05 12:00 |
20:13:21.19 |
-64:25:30.2 |
HIP 99772 |
7.96 |
| 2026-10-06 00:00 |
20:13:19.91 |
-64:25:12.5 |
HIP 99772 |
8.12 |
| 2026-10-06 12:00 |
20:13:18.66 |
-64:24:54.7 |
HIP 99772 |
8.28 |
| 2026-10-07 00:00 |
20:13:17.46 |
-64:24:36.9 |
HIP 99772 |
8.44 |
| 2026-10-07 12:00 |
20:13:16.28 |
-64:24:19.0 |
HIP 99772 |
8.61 |
| 2026-10-08 00:00 |
20:13:15.15 |
-64:24:00.9 |
HIP 99772 |
8.79 |
| 2026-10-08 12:00 |
20:13:14.05 |
-64:23:42.8 |
HIP 99772 |
8.97 |
| 2026-10-09 00:00 |
20:13:12.99 |
-64:23:24.7 |
HIP 99772 |
9.16 |
| 2026-10-09 12:00 |
20:13:11.96 |
-64:23:06.4 |
HIP 99772 |
9.35 |
| 2026-10-10 00:00 |
20:13:10.97 |
-64:22:48.1 |
HIP 99772 |
9.54 |
| 2026-10-10 12:00 |
20:13:10.02 |
-64:22:29.6 |
HIP 99772 |
9.74 |
| 2026-10-11 00:00 |
20:13:09.11 |
-64:22:11.1 |
HIP 99772 |
9.94 |