メタデータ
| 項目 |
値 |
| Designation |
C/1997 A1 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1997-06-19T14:28:23.399040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:50Z |
| Obs used |
197 |
| NEO |
- |
| M1 |
9.500 |
| K1 |
10.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1997-03-14.0000000 |
| e |
1.00212808 |
| q (au) |
3.157173 |
| a (au) |
-1483.580380 |
| i (deg) |
145.071692 |
| Ω (om, deg) |
135.766697 |
| ω (w, deg) |
40.016058 |
| M (ma, deg) |
-0.001683 |
等級
散乱 + 全体線形
$$
M_a = (7.011 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
7.011 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
20:48:35.77 |
-24:20:09.6 |
HIP 102822 |
33.56 |
| 2026-05-12 12:00 |
20:48:35.21 |
-24:20:16.6 |
HIP 102822 |
33.52 |
| 2026-05-13 00:00 |
20:48:34.64 |
-24:20:23.8 |
HIP 102822 |
33.49 |
| 2026-05-13 12:00 |
20:48:34.04 |
-24:20:31.0 |
HIP 102822 |
33.45 |
| 2026-05-14 00:00 |
20:48:33.42 |
-24:20:38.3 |
HIP 102822 |
33.42 |
| 2026-05-14 12:00 |
20:48:32.78 |
-24:20:45.7 |
HIP 102822 |
33.39 |
| 2026-05-15 00:00 |
20:48:32.12 |
-24:20:53.1 |
HIP 102822 |
33.36 |
| 2026-05-15 12:00 |
20:48:31.44 |
-24:21:00.7 |
HIP 102822 |
33.34 |
| 2026-05-16 00:00 |
20:48:30.74 |
-24:21:08.2 |
HIP 102822 |
33.31 |
| 2026-05-16 12:00 |
20:48:30.02 |
-24:21:15.9 |
HIP 102822 |
33.29 |
| 2026-05-17 00:00 |
20:48:29.27 |
-24:21:23.6 |
HIP 102822 |
33.28 |
| 2026-05-17 12:00 |
20:48:28.51 |
-24:21:31.4 |
HIP 102822 |
33.26 |
| 2026-05-18 00:00 |
20:48:27.72 |
-24:21:39.3 |
HIP 102822 |
33.25 |
| 2026-05-18 12:00 |
20:48:26.92 |
-24:21:47.2 |
HIP 102822 |
33.24 |
| 2026-05-19 00:00 |
20:48:26.09 |
-24:21:55.2 |
HIP 102822 |
33.24 |
| 2026-05-19 12:00 |
20:48:25.25 |
-24:22:03.3 |
HIP 102822 |
33.24 |
| 2026-05-20 00:00 |
20:48:24.38 |
-24:22:11.4 |
HIP 102822 |
33.24 |
| 2026-05-20 12:00 |
20:48:23.49 |
-24:22:19.6 |
HIP 102822 |
33.25 |
| 2026-05-21 00:00 |
20:48:22.59 |
-24:22:27.9 |
HIP 102822 |
33.26 |
| 2026-05-21 12:00 |
20:48:21.66 |
-24:22:36.2 |
HIP 102822 |
33.27 |
| 2026-05-22 00:00 |
20:48:20.71 |
-24:22:44.6 |
HIP 102822 |
33.29 |
| 2026-05-22 12:00 |
20:48:19.74 |
-24:22:53.0 |
HIP 102822 |
33.31 |
| 2026-05-23 00:00 |
20:48:18.76 |
-24:23:01.6 |
HIP 102822 |
33.34 |
| 2026-05-23 12:00 |
20:48:17.75 |
-24:23:10.1 |
HIP 102822 |
33.36 |
| 2026-05-24 00:00 |
20:48:16.72 |
-24:23:18.8 |
HIP 102822 |
33.40 |
| 2026-05-24 12:00 |
20:48:15.68 |
-24:23:27.5 |
HIP 102822 |
33.44 |
| 2026-05-25 00:00 |
20:48:14.61 |
-24:23:36.3 |
HIP 102822 |
33.48 |
| 2026-05-25 12:00 |
20:48:13.52 |
-24:23:45.1 |
HIP 102822 |
33.52 |
| 2026-05-26 00:00 |
20:48:12.42 |
-24:23:54.0 |
HIP 102822 |
33.57 |
| 2026-05-26 12:00 |
20:48:11.29 |
-24:24:02.9 |
HIP 102822 |
33.63 |
| 2026-05-27 00:00 |
20:48:10.15 |
-24:24:11.9 |
HIP 102822 |
33.69 |
| 2026-05-27 12:00 |
20:48:08.99 |
-24:24:21.0 |
HIP 102822 |
33.76 |
| 2026-05-28 00:00 |
20:48:07.80 |
-24:24:30.1 |
HIP 102822 |
33.83 |
| 2026-05-28 12:00 |
20:48:06.60 |
-24:24:39.2 |
HIP 102822 |
33.90 |
| 2026-05-29 00:00 |
20:48:05.38 |
-24:24:48.5 |
HIP 102822 |
33.98 |
| 2026-05-29 12:00 |
20:48:04.14 |
-24:24:57.8 |
HIP 102822 |
34.07 |
| 2026-05-30 00:00 |
20:48:02.88 |
-24:25:07.1 |
HIP 102822 |
34.16 |
| 2026-05-30 12:00 |
20:48:01.60 |
-24:25:16.5 |
HIP 102822 |
34.25 |
| 2026-05-31 00:00 |
20:48:00.31 |
-24:25:25.9 |
HIP 102822 |
34.35 |
| 2026-05-31 12:00 |
20:47:58.99 |
-24:25:35.4 |
HIP 102822 |
34.46 |
| 2026-06-01 00:00 |
20:47:57.66 |
-24:25:45.0 |
HIP 102822 |
34.57 |
| 2026-06-01 12:00 |
20:47:56.31 |
-24:25:54.6 |
HIP 102822 |
34.69 |
| 2026-06-02 00:00 |
20:47:54.94 |
-24:26:04.2 |
HIP 102516 |
34.44 |