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) |
| 2026-03-26 00:00 |
20:28:03.91 |
-63:35:18.5 |
HIP 101259 |
27.73 |
| 2026-03-26 12:00 |
20:28:06.09 |
-63:35:33.7 |
HIP 101259 |
27.67 |
| 2026-03-27 00:00 |
20:28:08.24 |
-63:35:49.1 |
HIP 101259 |
27.62 |
| 2026-03-27 12:00 |
20:28:10.35 |
-63:36:04.6 |
HIP 101259 |
27.58 |
| 2026-03-28 00:00 |
20:28:12.44 |
-63:36:20.3 |
HIP 101259 |
27.54 |
| 2026-03-28 12:00 |
20:28:14.49 |
-63:36:36.0 |
HIP 101259 |
27.52 |
| 2026-03-29 00:00 |
20:28:16.51 |
-63:36:51.9 |
HIP 101259 |
27.50 |
| 2026-03-29 12:00 |
20:28:18.51 |
-63:37:07.9 |
HIP 101259 |
27.49 |
| 2026-03-30 00:00 |
20:28:20.46 |
-63:37:24.0 |
HIP 101259 |
27.49 |
| 2026-03-30 12:00 |
20:28:22.39 |
-63:37:40.2 |
HIP 101259 |
27.50 |
| 2026-03-31 00:00 |
20:28:24.29 |
-63:37:56.5 |
HIP 101259 |
27.51 |
| 2026-03-31 12:00 |
20:28:26.15 |
-63:38:12.9 |
HIP 101259 |
27.54 |
| 2026-04-01 00:00 |
20:28:27.98 |
-63:38:29.5 |
HIP 101259 |
27.57 |
| 2026-04-01 12:00 |
20:28:29.78 |
-63:38:46.2 |
HIP 101259 |
27.61 |
| 2026-04-02 00:00 |
20:28:31.55 |
-63:39:02.9 |
HIP 101259 |
27.66 |
| 2026-04-02 12:00 |
20:28:33.28 |
-63:39:19.8 |
HIP 101259 |
27.72 |
| 2026-04-03 00:00 |
20:28:34.98 |
-63:39:36.8 |
HIP 101259 |
27.78 |
| 2026-04-03 12:00 |
20:28:36.65 |
-63:39:53.9 |
HIP 101259 |
27.85 |
| 2026-04-04 00:00 |
20:28:38.28 |
-63:40:11.1 |
HIP 101259 |
27.93 |
| 2026-04-04 12:00 |
20:28:39.89 |
-63:40:28.4 |
HIP 101259 |
28.02 |
| 2026-04-05 00:00 |
20:28:41.46 |
-63:40:45.8 |
HIP 101259 |
28.12 |
| 2026-04-05 12:00 |
20:28:42.99 |
-63:41:03.3 |
HIP 101259 |
28.22 |
| 2026-04-06 00:00 |
20:28:44.49 |
-63:41:20.9 |
HIP 101259 |
28.33 |
| 2026-04-06 12:00 |
20:28:45.96 |
-63:41:38.6 |
HIP 101259 |
28.45 |
| 2026-04-07 00:00 |
20:28:47.40 |
-63:41:56.4 |
HIP 101259 |
28.57 |
| 2026-04-07 12:00 |
20:28:48.80 |
-63:42:14.3 |
HIP 101259 |
28.71 |
| 2026-04-08 00:00 |
20:28:50.17 |
-63:42:32.3 |
HIP 101259 |
28.84 |
| 2026-04-08 12:00 |
20:28:51.50 |
-63:42:50.4 |
HIP 101259 |
28.99 |
| 2026-04-09 00:00 |
20:28:52.80 |
-63:43:08.6 |
HIP 101259 |
29.14 |
| 2026-04-09 12:00 |
20:28:54.07 |
-63:43:26.9 |
HIP 101259 |
29.30 |
| 2026-04-10 00:00 |
20:28:55.30 |
-63:43:45.2 |
HIP 101259 |
29.47 |
| 2026-04-10 12:00 |
20:28:56.50 |
-63:44:03.7 |
HIP 101182 |
29.36 |
| 2026-04-11 00:00 |
20:28:57.66 |
-63:44:22.2 |
HIP 101182 |
29.02 |
| 2026-04-11 12:00 |
20:28:58.79 |
-63:44:40.9 |
HIP 101182 |
28.69 |
| 2026-04-12 00:00 |
20:28:59.88 |
-63:44:59.6 |
HIP 101182 |
28.35 |
| 2026-04-12 12:00 |
20:29:00.94 |
-63:45:18.4 |
HIP 101182 |
28.02 |
| 2026-04-13 00:00 |
20:29:01.96 |
-63:45:37.3 |
HIP 101182 |
27.69 |
| 2026-04-13 12:00 |
20:29:02.95 |
-63:45:56.2 |
HIP 101182 |
27.35 |
| 2026-04-14 00:00 |
20:29:03.90 |
-63:46:15.3 |
HIP 101182 |
27.02 |
| 2026-04-14 12:00 |
20:29:04.82 |
-63:46:34.4 |
HIP 101182 |
26.68 |
| 2026-04-15 00:00 |
20:29:05.70 |
-63:46:53.6 |
HIP 101182 |
26.35 |
| 2026-04-15 12:00 |
20:29:06.55 |
-63:47:12.9 |
HIP 101182 |
26.02 |
| 2026-04-16 00:00 |
20:29:07.36 |
-63:47:32.2 |
HIP 101182 |
25.68 |