メタデータ
| 項目 |
値 |
| Designation |
C/1980 Y2 (Panther) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1981-01-27T07:35:59.709120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:29Z |
| Obs used |
200 |
| NEO |
- |
| M1 |
6.800 |
| K1 |
6.250 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1981-02-26.0000000 |
| e |
0.99865714 |
| q (au) |
1.657187 |
| a (au) |
1234.075622 |
| i (deg) |
82.646128 |
| Ω (om, deg) |
332.000700 |
| ω (w, deg) |
105.597962 |
| M (ma, deg) |
0.000675 |
等級
散乱 + 全体線形
$$
M_a = (5.548 + 4.217\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
5.548 |
| n |
4.217 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.863 |
| δ90 |
1.000 |
| 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 |
| 1980-10-27 |
1981-01-26 |
+21.4786 |
-4.799 |
| 1981-01-27 |
1981-06-03 |
-0.3491 |
+0.057 |
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) |
| 2026-07-29 00:00 |
07:09:06.68 |
-70:40:01.9 |
HIP 34481 |
10.24 |
| 2026-07-29 12:00 |
07:09:11.30 |
-70:40:10.9 |
HIP 34481 |
10.46 |
| 2026-07-30 00:00 |
07:09:15.91 |
-70:40:20.2 |
HIP 34481 |
10.70 |
| 2026-07-30 12:00 |
07:09:20.51 |
-70:40:29.6 |
HIP 34481 |
10.95 |
| 2026-07-31 00:00 |
07:09:25.09 |
-70:40:39.3 |
HIP 34481 |
11.21 |
| 2026-07-31 12:00 |
07:09:29.66 |
-70:40:49.1 |
HIP 34481 |
11.49 |
| 2026-08-01 00:00 |
07:09:34.21 |
-70:40:59.1 |
HIP 34481 |
11.77 |
| 2026-08-01 12:00 |
07:09:38.75 |
-70:41:09.3 |
HIP 34481 |
12.07 |
| 2026-08-02 00:00 |
07:09:43.27 |
-70:41:19.7 |
HIP 34481 |
12.37 |
| 2026-08-02 12:00 |
07:09:47.77 |
-70:41:30.3 |
HIP 34481 |
12.68 |
| 2026-08-03 00:00 |
07:09:52.26 |
-70:41:41.0 |
HIP 34481 |
13.00 |
| 2026-08-03 12:00 |
07:09:56.74 |
-70:41:52.0 |
HIP 34481 |
13.33 |
| 2026-08-04 00:00 |
07:10:01.19 |
-70:42:03.1 |
HIP 34481 |
13.66 |
| 2026-08-04 12:00 |
07:10:05.63 |
-70:42:14.5 |
HIP 34481 |
14.00 |
| 2026-08-05 00:00 |
07:10:10.06 |
-70:42:26.0 |
HIP 34481 |
14.35 |
| 2026-08-05 12:00 |
07:10:14.46 |
-70:42:37.7 |
HIP 34481 |
14.70 |
| 2026-08-06 00:00 |
07:10:18.85 |
-70:42:49.6 |
HIP 34481 |
15.06 |
| 2026-08-06 12:00 |
07:10:23.22 |
-70:43:01.6 |
HIP 34481 |
15.42 |
| 2026-08-07 00:00 |
07:10:27.57 |
-70:43:13.9 |
HIP 34481 |
15.78 |
| 2026-08-07 12:00 |
07:10:31.90 |
-70:43:26.3 |
HIP 34481 |
16.15 |
| 2026-08-08 00:00 |
07:10:36.21 |
-70:43:38.9 |
HIP 34481 |
16.52 |
| 2026-08-08 12:00 |
07:10:40.51 |
-70:43:51.7 |
HIP 34481 |
16.90 |
| 2026-08-09 00:00 |
07:10:44.78 |
-70:44:04.7 |
HIP 34481 |
17.28 |
| 2026-08-09 12:00 |
07:10:49.04 |
-70:44:17.8 |
HIP 34481 |
17.66 |
| 2026-08-10 00:00 |
07:10:53.27 |
-70:44:31.2 |
HIP 34481 |
18.05 |
| 2026-08-10 12:00 |
07:10:57.49 |
-70:44:44.7 |
HIP 34481 |
18.44 |
| 2026-08-11 00:00 |
07:11:01.68 |
-70:44:58.4 |
HIP 34481 |
18.83 |
| 2026-08-11 12:00 |
07:11:05.85 |
-70:45:12.2 |
HIP 34481 |
19.22 |
| 2026-08-12 00:00 |
07:11:10.00 |
-70:45:26.3 |
HIP 34481 |
19.62 |
| 2026-08-12 12:00 |
07:11:14.13 |
-70:45:40.5 |
HIP 34481 |
20.01 |
| 2026-08-13 00:00 |
07:11:18.23 |
-70:45:54.9 |
HIP 34481 |
20.41 |
| 2026-08-13 12:00 |
07:11:22.32 |
-70:46:09.5 |
HIP 34481 |
20.81 |
| 2026-08-14 00:00 |
07:11:26.38 |
-70:46:24.2 |
HIP 34481 |
21.21 |
| 2026-08-14 12:00 |
07:11:30.41 |
-70:46:39.1 |
HIP 34481 |
21.62 |
| 2026-08-15 00:00 |
07:11:34.43 |
-70:46:54.2 |
HIP 34481 |
22.02 |
| 2026-08-15 12:00 |
07:11:38.42 |
-70:47:09.4 |
HIP 34481 |
22.43 |
| 2026-08-16 00:00 |
07:11:42.38 |
-70:47:24.9 |
HIP 34481 |
22.83 |
| 2026-08-16 12:00 |
07:11:46.33 |
-70:47:40.4 |
HIP 34481 |
23.24 |
| 2026-08-17 00:00 |
07:11:50.24 |
-70:47:56.2 |
HIP 34481 |
23.65 |
| 2026-08-17 12:00 |
07:11:54.14 |
-70:48:12.1 |
HIP 34481 |
24.06 |
| 2026-08-18 00:00 |
07:11:58.00 |
-70:48:28.2 |
HIP 34481 |
24.47 |
| 2026-08-18 12:00 |
07:12:01.85 |
-70:48:44.4 |
HIP 34481 |
24.88 |
| 2026-08-19 00:00 |
07:12:05.66 |
-70:49:00.8 |
HIP 34481 |
25.30 |