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 |
|---|---|---|---|
| 1980-07-18 | 1980-12-26 | +3.8790 | +2.471 |
| 1981-01-04 | 1981-01-13 | -4.4106 | -1.323 |
| 1981-01-13 | 1981-03-19 | +2.3906 | +0.176 |
| 1981-03-19 | 1981-08-27 | +16.6012 | -2.981 |
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) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 20:11:34.85 | -14:19:22.9 | HIP 99322 | 28.77 |
| 2026-02-03 12:00 | 20:11:36.50 | -14:19:17.3 | HIP 99322 | 29.16 |
| 2026-02-04 00:00 | 20:11:38.15 | -14:19:11.6 | HIP 99322 | 29.56 |
| 2026-02-04 12:00 | 20:11:39.79 | -14:19:05.9 | HIP 99322 | 29.95 |
| 2026-02-05 00:00 | 20:11:41.42 | -14:19:00.2 | HIP 99322 | 30.34 |
| 2026-02-05 12:00 | 20:11:43.06 | -14:18:54.5 | HIP 99690 | 30.37 |
| 2026-02-06 00:00 | 20:11:44.69 | -14:18:48.8 | HIP 99690 | 29.97 |
| 2026-02-06 12:00 | 20:11:46.31 | -14:18:43.1 | HIP 99690 | 29.56 |
| 2026-02-07 00:00 | 20:11:47.93 | -14:18:37.4 | HIP 99690 | 29.16 |
| 2026-02-07 12:00 | 20:11:49.55 | -14:18:31.6 | HIP 99690 | 28.75 |
| 2026-02-08 00:00 | 20:11:51.16 | -14:18:25.9 | HIP 99690 | 28.35 |
| 2026-02-08 12:00 | 20:11:52.77 | -14:18:20.1 | HIP 99690 | 27.95 |
| 2026-02-09 00:00 | 20:11:54.37 | -14:18:14.4 | HIP 99690 | 27.55 |
| 2026-02-09 12:00 | 20:11:55.97 | -14:18:08.6 | HIP 99690 | 27.15 |
| 2026-02-10 00:00 | 20:11:57.56 | -14:18:02.8 | HIP 99690 | 26.75 |
| 2026-02-10 12:00 | 20:11:59.15 | -14:17:57.1 | HIP 99690 | 26.36 |
| 2026-02-11 00:00 | 20:12:00.73 | -14:17:51.3 | HIP 99690 | 25.96 |
| 2026-02-11 12:00 | 20:12:02.31 | -14:17:45.5 | HIP 99690 | 25.57 |
| 2026-02-12 00:00 | 20:12:03.89 | -14:17:39.7 | HIP 99690 | 25.18 |
| 2026-02-12 12:00 | 20:12:05.45 | -14:17:33.9 | HIP 99690 | 24.78 |
| 2026-02-13 00:00 | 20:12:07.01 | -14:17:28.1 | HIP 99690 | 24.39 |
| 2026-02-13 12:00 | 20:12:08.57 | -14:17:22.3 | HIP 99690 | 24.00 |
| 2026-02-14 00:00 | 20:12:10.12 | -14:17:16.5 | HIP 99690 | 23.62 |
| 2026-02-14 12:00 | 20:12:11.66 | -14:17:10.7 | HIP 99690 | 23.23 |
| 2026-02-15 00:00 | 20:12:13.20 | -14:17:04.9 | HIP 99690 | 22.84 |
| 2026-02-15 12:00 | 20:12:14.73 | -14:16:59.1 | HIP 99690 | 22.46 |
| 2026-02-16 00:00 | 20:12:16.26 | -14:16:53.3 | HIP 99690 | 22.08 |
| 2026-02-16 12:00 | 20:12:17.78 | -14:16:47.5 | HIP 99690 | 21.70 |
| 2026-02-17 00:00 | 20:12:19.29 | -14:16:41.7 | HIP 99690 | 21.32 |
| 2026-02-17 12:00 | 20:12:20.80 | -14:16:35.9 | HIP 99690 | 20.94 |
| 2026-02-18 00:00 | 20:12:22.30 | -14:16:30.1 | HIP 99690 | 20.57 |
| 2026-02-18 12:00 | 20:12:23.79 | -14:16:24.3 | HIP 99690 | 20.19 |
| 2026-02-19 00:00 | 20:12:25.27 | -14:16:18.5 | HIP 99690 | 19.82 |
| 2026-02-19 12:00 | 20:12:26.75 | -14:16:12.7 | HIP 99690 | 19.45 |
| 2026-02-20 00:00 | 20:12:28.22 | -14:16:06.9 | HIP 99690 | 19.08 |
| 2026-02-20 12:00 | 20:12:29.68 | -14:16:01.1 | HIP 99690 | 18.71 |
| 2026-02-21 00:00 | 20:12:31.14 | -14:15:55.4 | HIP 99690 | 18.35 |
| 2026-02-21 12:00 | 20:12:32.59 | -14:15:49.6 | HIP 99690 | 17.99 |
| 2026-02-22 00:00 | 20:12:34.03 | -14:15:43.8 | HIP 99690 | 17.62 |
| 2026-02-22 12:00 | 20:12:35.46 | -14:15:38.0 | HIP 99690 | 17.26 |
| 2026-02-23 00:00 | 20:12:36.89 | -14:15:32.3 | HIP 99690 | 16.91 |
| 2026-02-23 12:00 | 20:12:38.30 | -14:15:26.5 | HIP 99690 | 16.55 |
| 2026-02-24 00:00 | 20:12:39.71 | -14:15:20.8 | HIP 99690 | 16.20 |