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) |
| 2026-09-20 00:00 |
20:39:44.72 |
-25:00:44.2 |
HIP 102047 |
14.88 |
| 2026-09-20 12:00 |
20:39:43.03 |
-25:00:48.1 |
HIP 102047 |
15.24 |
| 2026-09-21 00:00 |
20:39:41.36 |
-25:00:52.0 |
HIP 102047 |
15.61 |
| 2026-09-21 12:00 |
20:39:39.71 |
-25:00:55.7 |
HIP 102047 |
15.97 |
| 2026-09-22 00:00 |
20:39:38.07 |
-25:00:59.3 |
HIP 102047 |
16.33 |
| 2026-09-22 12:00 |
20:39:36.46 |
-25:01:02.9 |
HIP 102047 |
16.69 |
| 2026-09-23 00:00 |
20:39:34.86 |
-25:01:06.4 |
HIP 102047 |
17.04 |
| 2026-09-23 12:00 |
20:39:33.27 |
-25:01:09.7 |
HIP 102047 |
17.39 |
| 2026-09-24 00:00 |
20:39:31.71 |
-25:01:13.0 |
HIP 102047 |
17.74 |
| 2026-09-24 12:00 |
20:39:30.16 |
-25:01:16.3 |
HIP 102047 |
18.08 |
| 2026-09-25 00:00 |
20:39:28.63 |
-25:01:19.4 |
HIP 102047 |
18.42 |
| 2026-09-25 12:00 |
20:39:27.12 |
-25:01:22.5 |
HIP 102047 |
18.76 |
| 2026-09-26 00:00 |
20:39:25.63 |
-25:01:25.4 |
HIP 102047 |
19.09 |
| 2026-09-26 12:00 |
20:39:24.15 |
-25:01:28.3 |
HIP 102047 |
19.42 |
| 2026-09-27 00:00 |
20:39:22.69 |
-25:01:31.1 |
HIP 102047 |
19.75 |
| 2026-09-27 12:00 |
20:39:21.26 |
-25:01:33.8 |
HIP 102047 |
20.07 |
| 2026-09-28 00:00 |
20:39:19.84 |
-25:01:36.4 |
HIP 102047 |
20.39 |
| 2026-09-28 12:00 |
20:39:18.43 |
-25:01:39.0 |
HIP 101808 |
20.14 |
| 2026-09-29 00:00 |
20:39:17.05 |
-25:01:41.4 |
HIP 101808 |
19.82 |
| 2026-09-29 12:00 |
20:39:15.69 |
-25:01:43.8 |
HIP 101808 |
19.51 |
| 2026-09-30 00:00 |
20:39:14.34 |
-25:01:46.1 |
HIP 101808 |
19.21 |
| 2026-09-30 12:00 |
20:39:13.01 |
-25:01:48.3 |
HIP 101808 |
18.91 |
| 2026-10-01 00:00 |
20:39:11.71 |
-25:01:50.4 |
HIP 101808 |
18.61 |
| 2026-10-01 12:00 |
20:39:10.42 |
-25:01:52.5 |
HIP 101808 |
18.32 |
| 2026-10-02 00:00 |
20:39:09.15 |
-25:01:54.4 |
HIP 101808 |
18.04 |
| 2026-10-02 12:00 |
20:39:07.90 |
-25:01:56.3 |
HIP 101808 |
17.76 |
| 2026-10-03 00:00 |
20:39:06.67 |
-25:01:58.1 |
HIP 101808 |
17.48 |
| 2026-10-03 12:00 |
20:39:05.46 |
-25:01:59.8 |
HIP 101808 |
17.21 |
| 2026-10-04 00:00 |
20:39:04.27 |
-25:02:01.4 |
HIP 101808 |
16.94 |
| 2026-10-04 12:00 |
20:39:03.09 |
-25:02:02.9 |
HIP 101808 |
16.68 |
| 2026-10-05 00:00 |
20:39:01.94 |
-25:02:04.3 |
HIP 101808 |
16.42 |
| 2026-10-05 12:00 |
20:39:00.81 |
-25:02:05.7 |
HIP 101808 |
16.17 |
| 2026-10-06 00:00 |
20:38:59.70 |
-25:02:06.9 |
HIP 101808 |
15.92 |
| 2026-10-06 12:00 |
20:38:58.61 |
-25:02:08.1 |
HIP 101808 |
15.68 |
| 2026-10-07 00:00 |
20:38:57.53 |
-25:02:09.2 |
HIP 101808 |
15.44 |
| 2026-10-07 12:00 |
20:38:56.48 |
-25:02:10.2 |
HIP 101808 |
15.21 |
| 2026-10-08 00:00 |
20:38:55.45 |
-25:02:11.1 |
HIP 101808 |
14.98 |
| 2026-10-08 12:00 |
20:38:54.44 |
-25:02:12.0 |
HIP 101808 |
14.75 |
| 2026-10-09 00:00 |
20:38:53.45 |
-25:02:12.7 |
HIP 101808 |
14.54 |
| 2026-10-09 12:00 |
20:38:52.48 |
-25:02:13.4 |
HIP 101808 |
14.32 |
| 2026-10-10 00:00 |
20:38:51.53 |
-25:02:14.0 |
HIP 101808 |
14.12 |
| 2026-10-10 12:00 |
20:38:50.60 |
-25:02:14.5 |
HIP 101808 |
13.91 |
| 2026-10-11 00:00 |
20:38:49.69 |
-25:02:14.9 |
HIP 101808 |
13.72 |