メタデータ
| 項目 |
値 |
| Designation |
21P/Giacobini-Zinner |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-09-10T06:22:53.924160Z |
| Orbit solution date (soln_date, UTC) |
2025-11-23T22:20:59Z |
| Obs used |
1993 |
| NEO |
Yes |
| M1 |
13.200 |
| K1 |
8.250 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-11-13.0000000 |
| e |
0.71047048 |
| q (au) |
1.013441 |
| a (au) |
3.500303 |
| i (deg) |
32.002592 |
| Ω (om, deg) |
195.404480 |
| ω (w, deg) |
172.812482 |
| M (ma, deg) |
314.658527 |
等級
散乱 + 全体線形
$$
M_a = (10.458 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.458 |
| n |
6.000 |
| gf |
0.983 |
| gb |
-0.641 |
| 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) |
| 2026-07-29 00:00 |
10:03:34.96 |
-05:13:52.9 |
HIP 49231 |
25.10 |
| 2026-07-29 12:00 |
10:04:01.52 |
-05:15:00.4 |
HIP 49231 |
27.38 |
| 2026-07-30 00:00 |
10:04:28.09 |
-05:16:08.8 |
HIP 49465 |
23.53 |
| 2026-07-30 12:00 |
10:04:54.67 |
-05:17:18.1 |
HIP 49465 |
17.06 |
| 2026-07-31 00:00 |
10:05:21.25 |
-05:18:28.2 |
HIP 49465 |
10.89 |
| 2026-07-31 12:00 |
10:05:47.83 |
-05:19:39.2 |
HIP 49465 |
6.00 |
| 2026-08-01 00:00 |
10:06:14.43 |
-05:20:51.1 |
HIP 49465 |
6.62 |
| 2026-08-01 12:00 |
10:06:41.03 |
-05:22:03.8 |
HIP 49465 |
11.92 |
| 2026-08-02 00:00 |
10:07:07.63 |
-05:23:17.4 |
HIP 49557 |
10.69 |
| 2026-08-02 12:00 |
10:07:34.24 |
-05:24:31.8 |
HIP 49557 |
11.79 |
| 2026-08-03 00:00 |
10:08:00.85 |
-05:25:47.0 |
HIP 49557 |
15.95 |
| 2026-08-03 12:00 |
10:08:27.47 |
-05:27:03.1 |
HIP 49557 |
21.45 |
| 2026-08-04 00:00 |
10:08:54.08 |
-05:28:20.1 |
HIP 49832 |
22.39 |
| 2026-08-04 12:00 |
10:09:20.70 |
-05:29:37.8 |
HIP 49832 |
15.82 |
| 2026-08-05 00:00 |
10:09:47.33 |
-05:30:56.4 |
HIP 49832 |
9.53 |
| 2026-08-05 12:00 |
10:10:13.95 |
-05:32:15.8 |
HIP 49832 |
4.76 |
| 2026-08-06 00:00 |
10:10:40.58 |
-05:33:36.0 |
HIP 49832 |
6.78 |
| 2026-08-06 12:00 |
10:11:07.20 |
-05:34:57.0 |
HIP 49832 |
12.68 |
| 2026-08-07 00:00 |
10:11:33.83 |
-05:36:18.8 |
HIP 49832 |
19.16 |
| 2026-08-07 12:00 |
10:12:00.46 |
-05:37:41.4 |
HIP 49832 |
25.79 |
| 2026-08-08 00:00 |
10:12:27.08 |
-05:39:04.7 |
HIP 50058 |
28.53 |
| 2026-08-08 12:00 |
10:12:53.70 |
-05:40:28.9 |
HIP 50058 |
27.89 |
| 2026-08-09 00:00 |
10:13:20.33 |
-05:41:53.9 |
HIP 50058 |
28.88 |
| 2026-08-09 12:00 |
10:13:46.95 |
-05:43:19.6 |
HIP 50105 |
30.14 |
| 2026-08-10 00:00 |
10:14:13.56 |
-05:44:46.1 |
HIP 50307 |
31.09 |
| 2026-08-10 12:00 |
10:14:40.17 |
-05:46:13.3 |
HIP 50307 |
24.32 |
| 2026-08-11 00:00 |
10:15:06.78 |
-05:47:41.3 |
HIP 50307 |
17.57 |
| 2026-08-11 12:00 |
10:15:33.38 |
-05:49:10.1 |
HIP 50307 |
10.85 |
| 2026-08-12 00:00 |
10:15:59.98 |
-05:50:39.6 |
HIP 50307 |
4.32 |
| 2026-08-12 12:00 |
10:16:26.57 |
-05:52:09.8 |
HIP 50307 |
3.41 |
| 2026-08-13 00:00 |
10:16:53.16 |
-05:53:40.8 |
HIP 50307 |
9.83 |
| 2026-08-13 12:00 |
10:17:19.73 |
-05:55:12.5 |
HIP 50307 |
16.55 |
| 2026-08-14 00:00 |
10:17:46.30 |
-05:56:44.9 |
HIP 50307 |
23.30 |
| 2026-08-14 12:00 |
10:18:12.86 |
-05:58:18.1 |
HIP 50450 |
27.15 |
| 2026-08-15 00:00 |
10:18:39.41 |
-05:59:51.9 |
HIP 50450 |
26.90 |
| 2026-08-15 12:00 |
10:19:05.95 |
-06:01:26.4 |
HIP 50649 |
25.22 |
| 2026-08-16 00:00 |
10:19:32.48 |
-06:03:01.7 |
HIP 50649 |
18.58 |
| 2026-08-16 12:00 |
10:19:58.99 |
-06:04:37.6 |
HIP 50649 |
12.10 |
| 2026-08-17 00:00 |
10:20:25.50 |
-06:06:14.2 |
HIP 50649 |
6.28 |
| 2026-08-17 12:00 |
10:20:51.99 |
-06:07:51.4 |
HIP 50649 |
4.94 |
| 2026-08-18 00:00 |
10:21:18.47 |
-06:09:29.4 |
HIP 50649 |
10.07 |
| 2026-08-18 12:00 |
10:21:44.94 |
-06:11:07.9 |
HIP 50649 |
16.43 |
| 2026-08-19 00:00 |
10:22:11.39 |
-06:12:47.2 |
HIP 50649 |
23.03 |