90P/Gehrels 1
メタデータ
| 項目 |
値 |
| Designation |
90P/Gehrels 1 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2017-06-19T06:36:36.149760Z |
| Orbit solution date (soln_date, UTC) |
2022-05-24T23:57:55Z |
| Obs used |
577 |
| NEO |
- |
| M1 |
7.000 |
| K1 |
18.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-02-16.0000000 |
| e |
0.50979286 |
| q (au) |
2.974897 |
| a (au) |
6.068654 |
| i (deg) |
9.635376 |
| Ω (om, deg) |
13.251828 |
| ω (w, deg) |
29.270027 |
| M (ma, deg) |
351.872780 |
等級
散乱 + 全体線形
$$
M_a = (8.608 + 4.725\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.608 |
| n |
4.725 |
| gf |
1.000 |
| gb |
-0.828 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2016-08-27 |
2017-01-18 |
+56.4715 |
-28.048 |
| 2017-07-30 |
2018-04-15 |
-5.8039 |
+3.002 |
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) |
| 2026-02-03 00:00 |
15:40:29.09 |
-25:46:22.9 |
HIP 76782 |
11.01 |
| 2026-02-03 12:00 |
15:40:35.69 |
-25:47:09.7 |
HIP 76782 |
11.63 |
| 2026-02-04 00:00 |
15:40:42.18 |
-25:47:56.3 |
HIP 76782 |
12.43 |
| 2026-02-04 12:00 |
15:40:48.57 |
-25:48:42.7 |
HIP 76782 |
13.39 |
| 2026-02-05 00:00 |
15:40:54.85 |
-25:49:28.7 |
HIP 76782 |
14.45 |
| 2026-02-05 12:00 |
15:41:01.02 |
-25:50:14.5 |
HIP 76782 |
15.60 |
| 2026-02-06 00:00 |
15:41:07.09 |
-25:51:00.0 |
HIP 76782 |
16.80 |
| 2026-02-06 12:00 |
15:41:13.04 |
-25:51:45.2 |
HIP 76782 |
18.04 |
| 2026-02-07 00:00 |
15:41:18.89 |
-25:52:30.2 |
HIP 76872 |
17.80 |
| 2026-02-07 12:00 |
15:41:24.63 |
-25:53:14.9 |
HIP 76872 |
16.65 |
| 2026-02-08 00:00 |
15:41:30.25 |
-25:53:59.3 |
HIP 76872 |
15.56 |
| 2026-02-08 12:00 |
15:41:35.77 |
-25:54:43.4 |
HIP 76872 |
14.55 |
| 2026-02-09 00:00 |
15:41:41.18 |
-25:55:27.3 |
HIP 76872 |
13.62 |
| 2026-02-09 12:00 |
15:41:46.47 |
-25:56:10.8 |
HIP 76872 |
12.79 |
| 2026-02-10 00:00 |
15:41:51.65 |
-25:56:54.1 |
HIP 76946 |
11.49 |
| 2026-02-10 12:00 |
15:41:56.72 |
-25:57:37.1 |
HIP 76946 |
10.23 |
| 2026-02-11 00:00 |
15:42:01.67 |
-25:58:19.8 |
HIP 76946 |
9.02 |
| 2026-02-11 12:00 |
15:42:06.52 |
-25:59:02.2 |
HIP 76946 |
7.88 |
| 2026-02-12 00:00 |
15:42:11.24 |
-25:59:44.3 |
HIP 76946 |
6.81 |
| 2026-02-12 12:00 |
15:42:15.85 |
-26:00:26.1 |
HIP 76946 |
5.86 |
| 2026-02-13 00:00 |
15:42:20.35 |
-26:01:07.6 |
HIP 76946 |
5.05 |
| 2026-02-13 12:00 |
15:42:24.73 |
-26:01:48.8 |
HIP 76946 |
4.47 |
| 2026-02-14 00:00 |
15:42:29.00 |
-26:02:29.7 |
HIP 76946 |
4.17 |
| 2026-02-14 12:00 |
15:42:33.14 |
-26:03:10.3 |
HIP 76946 |
4.19 |
| 2026-02-15 00:00 |
15:42:37.17 |
-26:03:50.6 |
HIP 76946 |
4.52 |
| 2026-02-15 12:00 |
15:42:41.08 |
-26:04:30.5 |
HIP 76946 |
5.08 |
| 2026-02-16 00:00 |
15:42:44.88 |
-26:05:10.2 |
HIP 76946 |
5.79 |
| 2026-02-16 12:00 |
15:42:48.55 |
-26:05:49.5 |
HIP 76946 |
6.59 |
| 2026-02-17 00:00 |
15:42:52.11 |
-26:06:28.6 |
HIP 76946 |
7.44 |
| 2026-02-17 12:00 |
15:42:55.55 |
-26:07:07.3 |
HIP 76946 |
8.31 |
| 2026-02-18 00:00 |
15:42:58.86 |
-26:07:45.6 |
HIP 76946 |
9.20 |
| 2026-02-18 12:00 |
15:43:02.06 |
-26:08:23.7 |
HIP 76946 |
10.08 |
| 2026-02-19 00:00 |
15:43:05.14 |
-26:09:01.4 |
HIP 76946 |
10.96 |
| 2026-02-19 12:00 |
15:43:08.09 |
-26:09:38.8 |
HIP 76946 |
11.83 |
| 2026-02-20 00:00 |
15:43:10.93 |
-26:10:15.9 |
HIP 76946 |
12.69 |
| 2026-02-20 12:00 |
15:43:13.64 |
-26:10:52.7 |
HIP 76946 |
13.53 |
| 2026-02-21 00:00 |
15:43:16.23 |
-26:11:29.1 |
HIP 76946 |
14.36 |
| 2026-02-21 12:00 |
15:43:18.70 |
-26:12:05.2 |
HIP 76946 |
15.16 |
| 2026-02-22 00:00 |
15:43:21.05 |
-26:12:40.9 |
HIP 76946 |
15.95 |
| 2026-02-22 12:00 |
15:43:23.28 |
-26:13:16.3 |
HIP 76946 |
16.72 |
| 2026-02-23 00:00 |
15:43:25.38 |
-26:13:51.4 |
HIP 76946 |
17.47 |
| 2026-02-23 12:00 |
15:43:27.36 |
-26:14:26.1 |
HIP 76946 |
18.19 |
| 2026-02-24 00:00 |
15:43:29.22 |
-26:15:00.5 |
HIP 76946 |
18.90 |