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) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 20:10:28.81 | -14:14:15.3 | HIP 99322 | 13.03 |
| 2026-07-29 12:00 | 20:10:27.12 | -14:14:21.1 | HIP 99322 | 12.61 |
| 2026-07-30 00:00 | 20:10:25.43 | -14:14:26.9 | HIP 99322 | 12.19 |
| 2026-07-30 12:00 | 20:10:23.74 | -14:14:32.7 | HIP 99322 | 11.77 |
| 2026-07-31 00:00 | 20:10:22.05 | -14:14:38.6 | HIP 99322 | 11.35 |
| 2026-07-31 12:00 | 20:10:20.37 | -14:14:44.5 | HIP 99322 | 10.93 |
| 2026-08-01 00:00 | 20:10:18.69 | -14:14:50.3 | HIP 99322 | 10.51 |
| 2026-08-01 12:00 | 20:10:17.01 | -14:14:56.2 | HIP 99322 | 10.09 |
| 2026-08-02 00:00 | 20:10:15.33 | -14:15:02.1 | HIP 99322 | 9.67 |
| 2026-08-02 12:00 | 20:10:13.66 | -14:15:08.0 | HIP 99322 | 9.26 |
| 2026-08-03 00:00 | 20:10:11.98 | -14:15:14.0 | HIP 99322 | 8.84 |
| 2026-08-03 12:00 | 20:10:10.31 | -14:15:19.9 | HIP 99322 | 8.42 |
| 2026-08-04 00:00 | 20:10:08.65 | -14:15:25.9 | HIP 99322 | 8.01 |
| 2026-08-04 12:00 | 20:10:06.98 | -14:15:31.8 | HIP 99322 | 7.59 |
| 2026-08-05 00:00 | 20:10:05.32 | -14:15:37.8 | HIP 99322 | 7.18 |
| 2026-08-05 12:00 | 20:10:03.66 | -14:15:43.8 | HIP 99322 | 6.76 |
| 2026-08-06 00:00 | 20:10:02.00 | -14:15:49.8 | HIP 99322 | 6.35 |
| 2026-08-06 12:00 | 20:10:00.35 | -14:15:55.8 | HIP 99322 | 5.94 |
| 2026-08-07 00:00 | 20:09:58.70 | -14:16:01.8 | HIP 99322 | 5.52 |
| 2026-08-07 12:00 | 20:09:57.06 | -14:16:07.9 | HIP 99322 | 5.11 |
| 2026-08-08 00:00 | 20:09:55.41 | -14:16:13.9 | HIP 99322 | 4.70 |
| 2026-08-08 12:00 | 20:09:53.77 | -14:16:19.9 | HIP 99322 | 4.29 |
| 2026-08-09 00:00 | 20:09:52.14 | -14:16:26.0 | HIP 99322 | 3.89 |
| 2026-08-09 12:00 | 20:09:50.51 | -14:16:32.1 | HIP 99322 | 3.48 |
| 2026-08-10 00:00 | 20:09:48.88 | -14:16:38.1 | HIP 99322 | 3.07 |
| 2026-08-10 12:00 | 20:09:47.26 | -14:16:44.2 | HIP 99322 | 2.67 |
| 2026-08-11 00:00 | 20:09:45.64 | -14:16:50.3 | HIP 99322 | 2.26 |
| 2026-08-11 12:00 | 20:09:44.03 | -14:16:56.4 | HIP 99322 | 1.86 |
| 2026-08-12 00:00 | 20:09:42.42 | -14:17:02.5 | HIP 99322 | 1.46 |
| 2026-08-12 12:00 | 20:09:40.82 | -14:17:08.6 | HIP 99322 | 1.07 |
| 2026-08-13 00:00 | 20:09:39.22 | -14:17:14.7 | HIP 99322 | 0.68 |
| 2026-08-13 12:00 | 20:09:37.62 | -14:17:20.8 | HIP 99322 | 0.33 |
| 2026-08-14 00:00 | 20:09:36.04 | -14:17:26.9 | HIP 99322 | 0.26 |
| 2026-08-14 12:00 | 20:09:34.45 | -14:17:33.0 | HIP 99322 | 0.59 |
| 2026-08-15 00:00 | 20:09:32.87 | -14:17:39.1 | HIP 99322 | 0.97 |
| 2026-08-15 12:00 | 20:09:31.30 | -14:17:45.2 | HIP 99322 | 1.36 |
| 2026-08-16 00:00 | 20:09:29.73 | -14:17:51.3 | HIP 99322 | 1.75 |
| 2026-08-16 12:00 | 20:09:28.17 | -14:17:57.4 | HIP 99322 | 2.14 |
| 2026-08-17 00:00 | 20:09:26.62 | -14:18:03.6 | HIP 99322 | 2.53 |
| 2026-08-17 12:00 | 20:09:25.07 | -14:18:09.7 | HIP 99322 | 2.91 |
| 2026-08-18 00:00 | 20:09:23.53 | -14:18:15.8 | HIP 99322 | 3.30 |
| 2026-08-18 12:00 | 20:09:21.99 | -14:18:21.9 | HIP 99322 | 3.68 |
| 2026-08-19 00:00 | 20:09:20.46 | -14:18:28.0 | HIP 99322 | 4.07 |