メタデータ
| 項目 |
値 |
| Designation |
270P/Gehrels |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2013-07-18T12:29:23.700480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:10Z |
| Obs used |
381 |
| NEO |
- |
| M1 |
13.700 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2008-07-20.0000000 |
| e |
0.46760427 |
| q (au) |
3.594521 |
| a (au) |
6.751596 |
| i (deg) |
2.859570 |
| Ω (om, deg) |
225.681440 |
| ω (w, deg) |
211.476072 |
| M (ma, deg) |
257.495456 |
等級
散乱 + 全体線形
$$
M_a = (7.051 + 5.884\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
7.051 |
| n |
5.884 |
| gf |
0.993 |
| gb |
-0.979 |
| 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
ファインディングチャート
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
20:14:00.48 |
-16:44:32.3 |
HIP 99708 |
4.41 |
| 2026-06-01 12:00 |
20:13:55.22 |
-16:44:38.0 |
HIP 99708 |
4.58 |
| 2026-06-02 00:00 |
20:13:49.85 |
-16:44:44.1 |
HIP 99708 |
5.09 |
| 2026-06-02 12:00 |
20:13:44.35 |
-16:44:50.7 |
HIP 99708 |
5.87 |
| 2026-06-03 00:00 |
20:13:38.74 |
-16:44:57.7 |
HIP 99708 |
6.84 |
| 2026-06-03 12:00 |
20:13:33.01 |
-16:45:05.0 |
HIP 99708 |
7.95 |
| 2026-06-04 00:00 |
20:13:27.17 |
-16:45:12.9 |
HIP 99708 |
9.16 |
| 2026-06-04 12:00 |
20:13:21.20 |
-16:45:21.1 |
HIP 99708 |
10.44 |
| 2026-06-05 00:00 |
20:13:15.12 |
-16:45:29.7 |
HIP 99708 |
11.79 |
| 2026-06-05 12:00 |
20:13:08.93 |
-16:45:38.8 |
HIP 99708 |
13.19 |
| 2026-06-06 00:00 |
20:13:02.62 |
-16:45:48.2 |
HIP 99708 |
14.64 |
| 2026-06-06 12:00 |
20:12:56.19 |
-16:45:58.1 |
HIP 99708 |
16.13 |
| 2026-06-07 00:00 |
20:12:49.65 |
-16:46:08.4 |
HIP 99708 |
17.65 |
| 2026-06-07 12:00 |
20:12:43.00 |
-16:46:19.1 |
HIP 99708 |
19.22 |
| 2026-06-08 00:00 |
20:12:36.23 |
-16:46:30.2 |
HIP 99708 |
20.81 |
| 2026-06-08 12:00 |
20:12:29.36 |
-16:46:41.7 |
HIP 99455 |
22.37 |
| 2026-06-09 00:00 |
20:12:22.37 |
-16:46:53.6 |
HIP 99455 |
20.84 |
| 2026-06-09 12:00 |
20:12:15.26 |
-16:47:05.9 |
HIP 99455 |
19.31 |
| 2026-06-10 00:00 |
20:12:08.05 |
-16:47:18.6 |
HIP 99455 |
17.79 |
| 2026-06-10 12:00 |
20:12:00.73 |
-16:47:31.8 |
HIP 99455 |
16.29 |
| 2026-06-11 00:00 |
20:11:53.30 |
-16:47:45.3 |
HIP 99455 |
14.82 |
| 2026-06-11 12:00 |
20:11:45.76 |
-16:47:59.2 |
HIP 99455 |
13.42 |
| 2026-06-12 00:00 |
20:11:38.11 |
-16:48:13.5 |
HIP 99455 |
12.10 |
| 2026-06-12 12:00 |
20:11:30.36 |
-16:48:28.2 |
HIP 99455 |
10.91 |
| 2026-06-13 00:00 |
20:11:22.50 |
-16:48:43.3 |
HIP 99455 |
9.93 |
| 2026-06-13 12:00 |
20:11:14.53 |
-16:48:58.8 |
HIP 99455 |
9.22 |
| 2026-06-14 00:00 |
20:11:06.46 |
-16:49:14.6 |
HIP 99455 |
8.88 |
| 2026-06-14 12:00 |
20:10:58.29 |
-16:49:30.9 |
HIP 99455 |
8.96 |
| 2026-06-15 00:00 |
20:10:50.01 |
-16:49:47.5 |
HIP 99455 |
9.46 |
| 2026-06-15 12:00 |
20:10:41.63 |
-16:50:04.5 |
HIP 99455 |
10.35 |
| 2026-06-16 00:00 |
20:10:33.15 |
-16:50:21.9 |
HIP 99455 |
11.54 |
| 2026-06-16 12:00 |
20:10:24.57 |
-16:50:39.7 |
HIP 99455 |
12.96 |
| 2026-06-17 00:00 |
20:10:15.89 |
-16:50:57.8 |
HIP 99455 |
14.56 |
| 2026-06-17 12:00 |
20:10:07.12 |
-16:51:16.3 |
HIP 99349 |
15.54 |
| 2026-06-18 00:00 |
20:09:58.25 |
-16:51:35.1 |
HIP 99349 |
14.91 |
| 2026-06-18 12:00 |
20:09:49.28 |
-16:51:54.3 |
HIP 99349 |
14.56 |
| 2026-06-19 00:00 |
20:09:40.22 |
-16:52:13.9 |
HIP 99349 |
14.53 |
| 2026-06-19 12:00 |
20:09:31.06 |
-16:52:33.8 |
HIP 99349 |
14.83 |
| 2026-06-20 00:00 |
20:09:21.81 |
-16:52:54.1 |
HIP 99349 |
15.45 |
| 2026-06-20 12:00 |
20:09:12.47 |
-16:53:14.7 |
HIP 99349 |
16.36 |
| 2026-06-21 00:00 |
20:09:03.05 |
-16:53:35.6 |
HIP 99349 |
17.53 |
| 2026-06-21 12:00 |
20:08:53.53 |
-16:53:56.9 |
HIP 99349 |
18.92 |
| 2026-06-22 00:00 |
20:08:43.92 |
-16:54:18.5 |
HIP 99349 |
20.48 |