メタデータ
| 項目 |
値 |
| Designation |
C/1971 E1 (Toba) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1971-04-17T05:58:54.240960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:19Z |
| Obs used |
137 |
| NEO |
- |
| M1 |
4.900 |
| K1 |
24.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1971-05-08.0000000 |
| e |
1.00097756 |
| q (au) |
1.233346 |
| a (au) |
-1261.660970 |
| i (deg) |
109.684237 |
| Ω (om, deg) |
104.077477 |
| ω (w, deg) |
152.361820 |
| M (ma, deg) |
0.000456 |
等級
散乱 + 全体線形
$$
M_a = (5.808 + 5.913\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
5.808 |
| n |
5.913 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.984 |
| 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 |
| 1971-04-18 |
1971-06-28 |
+16.5114 |
-2.215 |
| 1971-06-28 |
1971-09-09 |
-10.7727 |
+3.319 |
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) |
| 2026-03-26 00:00 |
07:36:53.02 |
-18:19:35.2 |
HIP 37097 |
11.01 |
| 2026-03-26 12:00 |
07:36:52.54 |
-18:19:20.4 |
HIP 37097 |
11.27 |
| 2026-03-27 00:00 |
07:36:52.07 |
-18:19:05.6 |
HIP 37097 |
11.54 |
| 2026-03-27 12:00 |
07:36:51.61 |
-18:18:50.7 |
HIP 37097 |
11.80 |
| 2026-03-28 00:00 |
07:36:51.17 |
-18:18:35.8 |
HIP 37097 |
12.05 |
| 2026-03-28 12:00 |
07:36:50.74 |
-18:18:21.0 |
HIP 37097 |
12.31 |
| 2026-03-29 00:00 |
07:36:50.32 |
-18:18:06.1 |
HIP 37097 |
12.57 |
| 2026-03-29 12:00 |
07:36:49.91 |
-18:17:51.2 |
HIP 37097 |
12.82 |
| 2026-03-30 00:00 |
07:36:49.52 |
-18:17:36.4 |
HIP 37097 |
13.07 |
| 2026-03-30 12:00 |
07:36:49.14 |
-18:17:21.5 |
HIP 37097 |
13.33 |
| 2026-03-31 00:00 |
07:36:48.78 |
-18:17:06.6 |
HIP 37097 |
13.58 |
| 2026-03-31 12:00 |
07:36:48.42 |
-18:16:51.7 |
HIP 37097 |
13.82 |
| 2026-04-01 00:00 |
07:36:48.08 |
-18:16:36.8 |
HIP 37097 |
14.07 |
| 2026-04-01 12:00 |
07:36:47.76 |
-18:16:21.9 |
HIP 37097 |
14.32 |
| 2026-04-02 00:00 |
07:36:47.44 |
-18:16:07.1 |
HIP 37097 |
14.56 |
| 2026-04-02 12:00 |
07:36:47.14 |
-18:15:52.2 |
HIP 37097 |
14.81 |
| 2026-04-03 00:00 |
07:36:46.85 |
-18:15:37.3 |
HIP 37097 |
15.05 |
| 2026-04-03 12:00 |
07:36:46.58 |
-18:15:22.5 |
HIP 37097 |
15.29 |
| 2026-04-04 00:00 |
07:36:46.31 |
-18:15:07.6 |
HIP 37097 |
15.53 |
| 2026-04-04 12:00 |
07:36:46.06 |
-18:14:52.8 |
HIP 37097 |
15.77 |
| 2026-04-05 00:00 |
07:36:45.83 |
-18:14:37.9 |
HIP 37097 |
16.00 |
| 2026-04-05 12:00 |
07:36:45.60 |
-18:14:23.1 |
HIP 37097 |
16.24 |
| 2026-04-06 00:00 |
07:36:45.39 |
-18:14:08.3 |
HIP 37097 |
16.47 |
| 2026-04-06 12:00 |
07:36:45.20 |
-18:13:53.5 |
HIP 37097 |
16.71 |
| 2026-04-07 00:00 |
07:36:45.01 |
-18:13:38.7 |
HIP 37097 |
16.94 |
| 2026-04-07 12:00 |
07:36:44.84 |
-18:13:23.9 |
HIP 37097 |
17.17 |
| 2026-04-08 00:00 |
07:36:44.68 |
-18:13:09.1 |
HIP 37097 |
17.40 |
| 2026-04-08 12:00 |
07:36:44.54 |
-18:12:54.4 |
HIP 37097 |
17.62 |
| 2026-04-09 00:00 |
07:36:44.41 |
-18:12:39.7 |
HIP 37097 |
17.85 |
| 2026-04-09 12:00 |
07:36:44.29 |
-18:12:25.0 |
HIP 37097 |
18.07 |
| 2026-04-10 00:00 |
07:36:44.18 |
-18:12:10.3 |
HIP 37097 |
18.30 |
| 2026-04-10 12:00 |
07:36:44.09 |
-18:11:55.6 |
HIP 37097 |
18.52 |
| 2026-04-11 00:00 |
07:36:44.01 |
-18:11:40.9 |
HIP 37097 |
18.74 |
| 2026-04-11 12:00 |
07:36:43.95 |
-18:11:26.3 |
HIP 37097 |
18.96 |
| 2026-04-12 00:00 |
07:36:43.89 |
-18:11:11.7 |
HIP 37097 |
19.18 |
| 2026-04-12 12:00 |
07:36:43.85 |
-18:10:57.1 |
HIP 37097 |
19.40 |
| 2026-04-13 00:00 |
07:36:43.83 |
-18:10:42.6 |
HIP 37097 |
19.61 |
| 2026-04-13 12:00 |
07:36:43.81 |
-18:10:28.1 |
HIP 37097 |
19.83 |
| 2026-04-14 00:00 |
07:36:43.81 |
-18:10:13.6 |
HIP 37097 |
20.04 |
| 2026-04-14 12:00 |
07:36:43.83 |
-18:09:59.1 |
HIP 37097 |
20.25 |
| 2026-04-15 00:00 |
07:36:43.85 |
-18:09:44.6 |
HIP 37097 |
20.46 |
| 2026-04-15 12:00 |
07:36:43.89 |
-18:09:30.2 |
HIP 37097 |
20.67 |
| 2026-04-16 00:00 |
07:36:43.94 |
-18:09:15.9 |
HIP 37097 |
20.88 |