C/1980 Y1 (Bradfield)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/1980 Y1 (Bradfield) |
| Type | C |
| Perihelion (tp_cal, UTC) | 1980-12-29T12:59:59.372160Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:29:29Z |
| Obs used | 32 |
| NEO | - |
| M1 | - |
| K1 | - |
| PC | 0.030 |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 1981-01-26.0000000 |
| e | 0.99972538 |
| q (au) | 0.259823 |
| a (au) | 946.110211 |
| i (deg) | 138.585179 |
| Ω (om, deg) | 115.351543 |
| ω (w, deg) | 358.294122 |
| M (ma, deg) | 0.000930 |
等級
散乱 + 全体線形
$$ M_a = (7.110 + 2.589\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 7.110 |
| n | 2.589 |
| gf | 0.800 |
| gb | -0.500 |
| k | 0.800 |
| 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 |
|---|---|---|---|
| 1981-01-04 | 1981-01-13 | -4.7670 | -1.473 |
| 1981-01-13 | 1981-01-31 | +3.4551 | +0.349 |
| 1981-01-31 | 1981-08-27 | +10.1983 | +0.293 |
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) |
|---|---|---|---|---|
| 2026-06-01 00:00 | 20:13:22.91 | -14:06:26.1 | HIP 99690 | 7.55 |
| 2026-06-01 12:00 | 20:13:21.84 | -14:06:27.8 | HIP 99690 | 7.72 |
| 2026-06-02 00:00 | 20:13:20.76 | -14:06:29.5 | HIP 99690 | 7.89 |
| 2026-06-02 12:00 | 20:13:19.67 | -14:06:31.3 | HIP 99690 | 8.07 |
| 2026-06-03 00:00 | 20:13:18.57 | -14:06:33.1 | HIP 99690 | 8.25 |
| 2026-06-03 12:00 | 20:13:17.46 | -14:06:34.9 | HIP 99690 | 8.44 |
| 2026-06-04 00:00 | 20:13:16.34 | -14:06:36.8 | HIP 99690 | 8.64 |
| 2026-06-04 12:00 | 20:13:15.20 | -14:06:38.8 | HIP 99690 | 8.84 |
| 2026-06-05 00:00 | 20:13:14.06 | -14:06:40.8 | HIP 99690 | 9.05 |
| 2026-06-05 12:00 | 20:13:12.90 | -14:06:42.9 | HIP 99690 | 9.27 |
| 2026-06-06 00:00 | 20:13:11.74 | -14:06:45.0 | HIP 99690 | 9.49 |
| 2026-06-06 12:00 | 20:13:10.56 | -14:06:47.1 | HIP 99690 | 9.71 |
| 2026-06-07 00:00 | 20:13:09.38 | -14:06:49.3 | HIP 99690 | 9.94 |
| 2026-06-07 12:00 | 20:13:08.18 | -14:06:51.6 | HIP 99690 | 10.17 |
| 2026-06-08 00:00 | 20:13:06.97 | -14:06:53.9 | HIP 99690 | 10.41 |
| 2026-06-08 12:00 | 20:13:05.76 | -14:06:56.2 | HIP 99690 | 10.66 |
| 2026-06-09 00:00 | 20:13:04.53 | -14:06:58.6 | HIP 99690 | 10.90 |
| 2026-06-09 12:00 | 20:13:03.29 | -14:07:01.0 | HIP 99690 | 11.16 |
| 2026-06-10 00:00 | 20:13:02.05 | -14:07:03.5 | HIP 99690 | 11.41 |
| 2026-06-10 12:00 | 20:13:00.79 | -14:07:06.0 | HIP 99690 | 11.67 |
| 2026-06-11 00:00 | 20:12:59.52 | -14:07:08.6 | HIP 99690 | 11.94 |
| 2026-06-11 12:00 | 20:12:58.25 | -14:07:11.2 | HIP 99690 | 12.21 |
| 2026-06-12 00:00 | 20:12:56.96 | -14:07:13.9 | HIP 99690 | 12.48 |
| 2026-06-12 12:00 | 20:12:55.67 | -14:07:16.6 | HIP 99690 | 12.76 |
| 2026-06-13 00:00 | 20:12:54.36 | -14:07:19.4 | HIP 99690 | 13.04 |
| 2026-06-13 12:00 | 20:12:53.05 | -14:07:22.2 | HIP 99690 | 13.32 |
| 2026-06-14 00:00 | 20:12:51.72 | -14:07:25.1 | HIP 99690 | 13.61 |
| 2026-06-14 12:00 | 20:12:50.39 | -14:07:28.0 | HIP 99690 | 13.90 |
| 2026-06-15 00:00 | 20:12:49.05 | -14:07:30.9 | HIP 99690 | 14.20 |
| 2026-06-15 12:00 | 20:12:47.70 | -14:07:33.9 | HIP 99690 | 14.49 |
| 2026-06-16 00:00 | 20:12:46.34 | -14:07:37.0 | HIP 99690 | 14.80 |
| 2026-06-16 12:00 | 20:12:44.97 | -14:07:40.0 | HIP 99690 | 15.10 |
| 2026-06-17 00:00 | 20:12:43.60 | -14:07:43.2 | HIP 99690 | 15.41 |
| 2026-06-17 12:00 | 20:12:42.21 | -14:07:46.3 | HIP 99690 | 15.72 |
| 2026-06-18 00:00 | 20:12:40.82 | -14:07:49.6 | HIP 99690 | 16.03 |
| 2026-06-18 12:00 | 20:12:39.42 | -14:07:52.8 | HIP 99690 | 16.35 |
| 2026-06-19 00:00 | 20:12:38.01 | -14:07:56.1 | HIP 99690 | 16.67 |
| 2026-06-19 12:00 | 20:12:36.59 | -14:07:59.5 | HIP 99690 | 16.99 |
| 2026-06-20 00:00 | 20:12:35.17 | -14:08:02.9 | HIP 99690 | 17.31 |
| 2026-06-20 12:00 | 20:12:33.74 | -14:08:06.3 | HIP 99690 | 17.64 |
| 2026-06-21 00:00 | 20:12:32.29 | -14:08:09.8 | HIP 99690 | 17.97 |
| 2026-06-21 12:00 | 20:12:30.85 | -14:08:13.3 | HIP 99690 | 18.30 |
| 2026-06-22 00:00 | 20:12:29.39 | -14:08:16.8 | HIP 99690 | 18.64 |