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) |
| 2026-07-29 00:00 |
20:43:49.27 |
-24:47:00.6 |
HIP 102290 |
6.50 |
| 2026-07-29 12:00 |
20:43:46.67 |
-24:47:11.3 |
HIP 102290 |
6.36 |
| 2026-07-30 00:00 |
20:43:44.08 |
-24:47:22.0 |
HIP 102290 |
6.29 |
| 2026-07-30 12:00 |
20:43:41.48 |
-24:47:32.6 |
HIP 102290 |
6.27 |
| 2026-07-31 00:00 |
20:43:38.88 |
-24:47:43.2 |
HIP 102290 |
6.31 |
| 2026-07-31 12:00 |
20:43:36.28 |
-24:47:53.7 |
HIP 102290 |
6.41 |
| 2026-08-01 00:00 |
20:43:33.68 |
-24:48:04.2 |
HIP 102290 |
6.57 |
| 2026-08-01 12:00 |
20:43:31.08 |
-24:48:14.7 |
HIP 102290 |
6.78 |
| 2026-08-02 00:00 |
20:43:28.49 |
-24:48:25.1 |
HIP 102290 |
7.03 |
| 2026-08-02 12:00 |
20:43:25.89 |
-24:48:35.5 |
HIP 102290 |
7.33 |
| 2026-08-03 00:00 |
20:43:23.29 |
-24:48:45.9 |
HIP 102290 |
7.67 |
| 2026-08-03 12:00 |
20:43:20.69 |
-24:48:56.2 |
HIP 102290 |
8.03 |
| 2026-08-04 00:00 |
20:43:18.10 |
-24:49:06.5 |
HIP 102290 |
8.43 |
| 2026-08-04 12:00 |
20:43:15.50 |
-24:49:16.7 |
HIP 102290 |
8.85 |
| 2026-08-05 00:00 |
20:43:12.91 |
-24:49:26.9 |
HIP 102290 |
9.29 |
| 2026-08-05 12:00 |
20:43:10.32 |
-24:49:37.0 |
HIP 102290 |
9.75 |
| 2026-08-06 00:00 |
20:43:07.73 |
-24:49:47.1 |
HIP 102290 |
10.22 |
| 2026-08-06 12:00 |
20:43:05.14 |
-24:49:57.2 |
HIP 102290 |
10.71 |
| 2026-08-07 00:00 |
20:43:02.55 |
-24:50:07.2 |
HIP 102290 |
11.21 |
| 2026-08-07 12:00 |
20:42:59.97 |
-24:50:17.2 |
HIP 102290 |
11.71 |
| 2026-08-08 00:00 |
20:42:57.39 |
-24:50:27.1 |
HIP 102290 |
12.23 |
| 2026-08-08 12:00 |
20:42:54.81 |
-24:50:37.0 |
HIP 102290 |
12.75 |
| 2026-08-09 00:00 |
20:42:52.23 |
-24:50:46.8 |
HIP 102290 |
13.28 |
| 2026-08-09 12:00 |
20:42:49.66 |
-24:50:56.6 |
HIP 102290 |
13.82 |
| 2026-08-10 00:00 |
20:42:47.09 |
-24:51:06.3 |
HIP 102290 |
14.36 |
| 2026-08-10 12:00 |
20:42:44.52 |
-24:51:16.0 |
HIP 102290 |
14.90 |
| 2026-08-11 00:00 |
20:42:41.96 |
-24:51:25.6 |
HIP 102290 |
15.45 |
| 2026-08-11 12:00 |
20:42:39.40 |
-24:51:35.2 |
HIP 102290 |
16.00 |
| 2026-08-12 00:00 |
20:42:36.84 |
-24:51:44.7 |
HIP 102290 |
16.55 |
| 2026-08-12 12:00 |
20:42:34.29 |
-24:51:54.2 |
HIP 102290 |
17.10 |
| 2026-08-13 00:00 |
20:42:31.75 |
-24:52:03.6 |
HIP 102290 |
17.66 |
| 2026-08-13 12:00 |
20:42:29.20 |
-24:52:13.0 |
HIP 102290 |
18.21 |
| 2026-08-14 00:00 |
20:42:26.67 |
-24:52:22.3 |
HIP 102290 |
18.77 |
| 2026-08-14 12:00 |
20:42:24.14 |
-24:52:31.5 |
HIP 102290 |
19.33 |
| 2026-08-15 00:00 |
20:42:21.61 |
-24:52:40.7 |
HIP 102290 |
19.89 |
| 2026-08-15 12:00 |
20:42:19.09 |
-24:52:49.8 |
HIP 102290 |
20.45 |
| 2026-08-16 00:00 |
20:42:16.57 |
-24:52:58.9 |
HIP 102290 |
21.01 |
| 2026-08-16 12:00 |
20:42:14.06 |
-24:53:07.9 |
HIP 102047 |
21.52 |
| 2026-08-17 00:00 |
20:42:11.56 |
-24:53:16.9 |
HIP 102047 |
20.95 |
| 2026-08-17 12:00 |
20:42:09.06 |
-24:53:25.8 |
HIP 102047 |
20.38 |
| 2026-08-18 00:00 |
20:42:06.57 |
-24:53:34.7 |
HIP 102047 |
19.81 |
| 2026-08-18 12:00 |
20:42:04.08 |
-24:53:43.4 |
HIP 102047 |
19.24 |
| 2026-08-19 00:00 |
20:42:01.61 |
-24:53:52.2 |
HIP 102047 |
18.68 |