21P/Giacobini-Zinner
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
$$
M_a = (10.463 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.463 |
| n |
6.000 |
| gf |
0.882 |
| gb |
-0.912 |
| k |
1.000 |
| δ90 |
9.999 |
| 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) |
| 2026-02-03 00:00 |
09:29:46.51 |
-21:17:39.5 |
HIP 46628 |
21.55 |
| 2026-02-03 12:00 |
09:29:17.92 |
-21:14:36.1 |
HIP 46628 |
23.27 |
| 2026-02-04 00:00 |
09:28:49.34 |
-21:11:29.0 |
HIP 46475 |
23.54 |
| 2026-02-04 12:00 |
09:28:20.76 |
-21:08:18.1 |
HIP 46475 |
20.93 |
| 2026-02-05 00:00 |
09:27:52.20 |
-21:05:03.6 |
HIP 46475 |
20.71 |
| 2026-02-05 12:00 |
09:27:23.65 |
-21:01:45.3 |
HIP 46475 |
22.98 |
| 2026-02-06 00:00 |
09:26:55.14 |
-20:58:23.4 |
HIP 46258 |
18.78 |
| 2026-02-06 12:00 |
09:26:26.65 |
-20:54:57.9 |
HIP 46258 |
11.73 |
| 2026-02-07 00:00 |
09:25:58.20 |
-20:51:28.8 |
HIP 46258 |
5.80 |
| 2026-02-07 12:00 |
09:25:29.80 |
-20:47:56.2 |
HIP 46258 |
6.49 |
| 2026-02-08 00:00 |
09:25:01.44 |
-20:44:20.1 |
HIP 46258 |
12.79 |
| 2026-02-08 12:00 |
09:24:33.15 |
-20:40:40.4 |
HIP 46258 |
19.98 |
| 2026-02-09 00:00 |
09:24:04.91 |
-20:36:57.4 |
HIP 46258 |
27.38 |
| 2026-02-09 12:00 |
09:23:36.74 |
-20:33:10.9 |
HIP 45932 |
25.31 |
| 2026-02-10 00:00 |
09:23:08.65 |
-20:29:21.1 |
HIP 45932 |
21.56 |
| 2026-02-10 12:00 |
09:22:40.63 |
-20:25:27.9 |
HIP 45932 |
20.18 |
| 2026-02-11 00:00 |
09:22:12.70 |
-20:21:31.5 |
HIP 45932 |
21.64 |
| 2026-02-11 12:00 |
09:21:44.86 |
-20:17:31.8 |
HIP 45932 |
25.46 |
| 2026-02-12 00:00 |
09:21:17.12 |
-20:13:28.9 |
HIP 45932 |
30.79 |
| 2026-02-12 12:00 |
09:20:49.48 |
-20:09:22.8 |
HIP 45801 |
33.57 |
| 2026-02-13 00:00 |
09:20:21.95 |
-20:05:13.7 |
HIP 45658 |
32.29 |
| 2026-02-13 12:00 |
09:19:54.54 |
-20:01:01.4 |
HIP 45658 |
29.87 |
| 2026-02-14 00:00 |
09:19:27.24 |
-19:56:46.2 |
HIP 45658 |
29.38 |
| 2026-02-14 12:00 |
09:19:00.07 |
-19:52:27.9 |
HIP 45658 |
30.91 |
| 2026-02-15 00:00 |
09:18:33.03 |
-19:48:06.8 |
HIP 45658 |
34.20 |
| 2026-02-15 12:00 |
09:18:06.13 |
-19:43:42.8 |
HIP 45506 |
28.64 |
| 2026-02-16 00:00 |
09:17:39.37 |
-19:39:15.9 |
HIP 45506 |
20.93 |
| 2026-02-16 12:00 |
09:17:12.75 |
-19:34:46.3 |
HIP 45506 |
13.23 |
| 2026-02-17 00:00 |
09:16:46.29 |
-19:30:13.9 |
HIP 45506 |
5.54 |
| 2026-02-17 12:00 |
09:16:19.99 |
-19:25:38.9 |
HIP 45506 |
2.33 |
| 2026-02-18 00:00 |
09:15:53.85 |
-19:21:01.3 |
HIP 45506 |
9.95 |
| 2026-02-18 12:00 |
09:15:27.88 |
-19:16:21.1 |
HIP 45506 |
17.65 |
| 2026-02-19 00:00 |
09:15:02.08 |
-19:11:38.4 |
HIP 45411 |
24.29 |
| 2026-02-19 12:00 |
09:14:36.46 |
-19:06:53.2 |
HIP 45339 |
26.59 |
| 2026-02-20 00:00 |
09:14:11.02 |
-19:02:05.7 |
HIP 45339 |
21.75 |
| 2026-02-20 12:00 |
09:13:45.77 |
-18:57:15.8 |
HIP 45339 |
18.85 |
| 2026-02-21 00:00 |
09:13:20.72 |
-18:52:23.7 |
HIP 45339 |
18.80 |
| 2026-02-21 12:00 |
09:12:55.86 |
-18:47:29.3 |
HIP 45339 |
21.61 |
| 2026-02-22 00:00 |
09:12:31.20 |
-18:42:32.8 |
HIP 45339 |
26.38 |
| 2026-02-22 12:00 |
09:12:06.75 |
-18:37:34.1 |
HIP 45339 |
32.23 |
| 2026-02-23 00:00 |
09:11:42.51 |
-18:32:33.5 |
HIP 45339 |
38.67 |
| 2026-02-23 12:00 |
09:11:18.48 |
-18:27:30.8 |
HIP 44923 |
32.78 |
| 2026-02-24 00:00 |
09:10:54.67 |
-18:22:26.2 |
HIP 44923 |
26.34 |