メタデータ
| 項目 |
値 |
| Designation |
C/2001 Q4 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2004-05-15T23:10:38.346240Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:11Z |
| Obs used |
2617 |
| NEO |
- |
| M1 |
8.000 |
| K1 |
6.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2004-05-15.0000000 |
| e |
1.00068805 |
| q (au) |
0.961960 |
| a (au) |
-1398.092298 |
| i (deg) |
99.642634 |
| Ω (om, deg) |
210.278440 |
| ω (w, deg) |
1.204371 |
| M (ma, deg) |
-0.000018 |
等級
散乱 + 全体線形
$$
M_a = (5.940 + 4.075\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
5.940 |
| n |
4.075 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
0.817 |
| δ90 |
9.991 |
| 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 |
| 2001-08-24 |
2004-03-09 |
-1.4351 |
-0.245 |
| 2004-03-09 |
2004-03-31 |
+6.4597 |
-1.163 |
| 2004-03-31 |
2004-05-15 |
-10.1442 |
+0.669 |
| 2004-05-15 |
2004-10-18 |
-1.2519 |
+0.669 |
| 2004-10-18 |
2006-08-18 |
+0.3692 |
+0.505 |
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) |
| 2026-05-12 00:00 |
01:41:42.14 |
+27:09:52.0 |
HIP 7894 |
3.71 |
| 2026-05-12 12:00 |
01:41:44.71 |
+27:10:07.8 |
HIP 7894 |
3.82 |
| 2026-05-13 00:00 |
01:41:47.27 |
+27:10:23.7 |
HIP 7894 |
4.03 |
| 2026-05-13 12:00 |
01:41:49.82 |
+27:10:39.5 |
HIP 7894 |
4.31 |
| 2026-05-14 00:00 |
01:41:52.36 |
+27:10:55.4 |
HIP 7894 |
4.66 |
| 2026-05-14 12:00 |
01:41:54.89 |
+27:11:11.3 |
HIP 7894 |
5.06 |
| 2026-05-15 00:00 |
01:41:57.41 |
+27:11:27.3 |
HIP 7894 |
5.50 |
| 2026-05-15 12:00 |
01:41:59.92 |
+27:11:43.3 |
HIP 7894 |
5.97 |
| 2026-05-16 00:00 |
01:42:02.42 |
+27:11:59.4 |
HIP 7894 |
6.46 |
| 2026-05-16 12:00 |
01:42:04.91 |
+27:12:15.4 |
HIP 7894 |
6.97 |
| 2026-05-17 00:00 |
01:42:07.39 |
+27:12:31.5 |
HIP 7894 |
7.50 |
| 2026-05-17 12:00 |
01:42:09.86 |
+27:12:47.6 |
HIP 7894 |
8.03 |
| 2026-05-18 00:00 |
01:42:12.32 |
+27:13:03.8 |
HIP 7894 |
8.57 |
| 2026-05-18 12:00 |
01:42:14.76 |
+27:13:20.0 |
HIP 7894 |
9.12 |
| 2026-05-19 00:00 |
01:42:17.20 |
+27:13:36.2 |
HIP 7894 |
9.67 |
| 2026-05-19 12:00 |
01:42:19.62 |
+27:13:52.4 |
HIP 7894 |
10.23 |
| 2026-05-20 00:00 |
01:42:22.03 |
+27:14:08.6 |
HIP 7894 |
10.78 |
| 2026-05-20 12:00 |
01:42:24.43 |
+27:14:24.9 |
HIP 7894 |
11.34 |
| 2026-05-21 00:00 |
01:42:26.81 |
+27:14:41.2 |
HIP 7894 |
11.90 |
| 2026-05-21 12:00 |
01:42:29.19 |
+27:14:57.5 |
HIP 7894 |
12.46 |
| 2026-05-22 00:00 |
01:42:31.55 |
+27:15:13.8 |
HIP 7894 |
13.03 |
| 2026-05-22 12:00 |
01:42:33.90 |
+27:15:30.1 |
HIP 7894 |
13.59 |
| 2026-05-23 00:00 |
01:42:36.24 |
+27:15:46.5 |
HIP 7894 |
14.15 |
| 2026-05-23 12:00 |
01:42:38.56 |
+27:16:02.8 |
HIP 7894 |
14.71 |
| 2026-05-24 00:00 |
01:42:40.87 |
+27:16:19.2 |
HIP 7894 |
15.27 |
| 2026-05-24 12:00 |
01:42:43.17 |
+27:16:35.6 |
HIP 7894 |
15.82 |
| 2026-05-25 00:00 |
01:42:45.45 |
+27:16:52.0 |
HIP 7894 |
16.38 |
| 2026-05-25 12:00 |
01:42:47.72 |
+27:17:08.4 |
HIP 7894 |
16.93 |
| 2026-05-26 00:00 |
01:42:49.98 |
+27:17:24.8 |
HIP 7894 |
17.49 |
| 2026-05-26 12:00 |
01:42:52.22 |
+27:17:41.2 |
HIP 7894 |
18.04 |
| 2026-05-27 00:00 |
01:42:54.45 |
+27:17:57.7 |
HIP 7894 |
18.59 |
| 2026-05-27 12:00 |
01:42:56.67 |
+27:18:14.1 |
HIP 7894 |
19.13 |
| 2026-05-28 00:00 |
01:42:58.87 |
+27:18:30.5 |
HIP 7894 |
19.68 |
| 2026-05-28 12:00 |
01:43:01.06 |
+27:18:47.0 |
HIP 7894 |
20.22 |
| 2026-05-29 00:00 |
01:43:03.23 |
+27:19:03.4 |
HIP 7894 |
20.76 |
| 2026-05-29 12:00 |
01:43:05.39 |
+27:19:19.9 |
HIP 7894 |
21.30 |
| 2026-05-30 00:00 |
01:43:07.53 |
+27:19:36.3 |
HIP 7894 |
21.84 |
| 2026-05-30 12:00 |
01:43:09.66 |
+27:19:52.7 |
HIP 7894 |
22.37 |
| 2026-05-31 00:00 |
01:43:11.78 |
+27:20:09.2 |
HIP 7894 |
22.90 |
| 2026-05-31 12:00 |
01:43:13.88 |
+27:20:25.6 |
HIP 7894 |
23.43 |
| 2026-06-01 00:00 |
01:43:15.96 |
+27:20:42.0 |
HIP 7894 |
23.95 |
| 2026-06-01 12:00 |
01:43:18.03 |
+27:20:58.4 |
HIP 7894 |
24.48 |
| 2026-06-02 00:00 |
01:43:20.08 |
+27:21:14.9 |
HIP 7894 |
25.00 |