メタデータ
| 項目 |
値 |
| Designation |
C/1885 X2 (Barnard) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1886-05-03T18:53:20.048640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:53Z |
| Obs used |
76 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1886-02-01.0000000 |
| e |
1.00020016 |
| q (au) |
0.479255 |
| a (au) |
-2394.381815 |
| i (deg) |
84.440812 |
| Ω (om, deg) |
69.909995 |
| ω (w, deg) |
119.624515 |
| M (ma, deg) |
-0.000772 |
等級
散乱 + 全体線形
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
04:50:31.71 |
-44:50:58.2 |
HIP 22537 |
7.19 |
| 2026-09-20 12:00 |
04:50:31.44 |
-44:51:08.7 |
HIP 22537 |
7.12 |
| 2026-09-21 00:00 |
04:50:31.17 |
-44:51:19.2 |
HIP 22537 |
7.05 |
| 2026-09-21 12:00 |
04:50:30.89 |
-44:51:29.7 |
HIP 22537 |
6.99 |
| 2026-09-22 00:00 |
04:50:30.60 |
-44:51:40.2 |
HIP 22537 |
6.93 |
| 2026-09-22 12:00 |
04:50:30.30 |
-44:51:50.6 |
HIP 22537 |
6.88 |
| 2026-09-23 00:00 |
04:50:29.99 |
-44:52:01.0 |
HIP 22537 |
6.83 |
| 2026-09-23 12:00 |
04:50:29.68 |
-44:52:11.4 |
HIP 22537 |
6.79 |
| 2026-09-24 00:00 |
04:50:29.35 |
-44:52:21.8 |
HIP 22537 |
6.76 |
| 2026-09-24 12:00 |
04:50:29.02 |
-44:52:32.1 |
HIP 22537 |
6.73 |
| 2026-09-25 00:00 |
04:50:28.67 |
-44:52:42.5 |
HIP 22537 |
6.71 |
| 2026-09-25 12:00 |
04:50:28.32 |
-44:52:52.8 |
HIP 22537 |
6.70 |
| 2026-09-26 00:00 |
04:50:27.96 |
-44:53:03.1 |
HIP 22537 |
6.69 |
| 2026-09-26 12:00 |
04:50:27.59 |
-44:53:13.3 |
HIP 22537 |
6.69 |
| 2026-09-27 00:00 |
04:50:27.21 |
-44:53:23.5 |
HIP 22537 |
6.70 |
| 2026-09-27 12:00 |
04:50:26.82 |
-44:53:33.8 |
HIP 22537 |
6.71 |
| 2026-09-28 00:00 |
04:50:26.42 |
-44:53:43.9 |
HIP 22537 |
6.73 |
| 2026-09-28 12:00 |
04:50:26.02 |
-44:53:54.1 |
HIP 22537 |
6.75 |
| 2026-09-29 00:00 |
04:50:25.60 |
-44:54:04.2 |
HIP 22537 |
6.79 |
| 2026-09-29 12:00 |
04:50:25.18 |
-44:54:14.3 |
HIP 22537 |
6.83 |
| 2026-09-30 00:00 |
04:50:24.75 |
-44:54:24.4 |
HIP 22537 |
6.87 |
| 2026-09-30 12:00 |
04:50:24.31 |
-44:54:34.4 |
HIP 22537 |
6.92 |
| 2026-10-01 00:00 |
04:50:23.86 |
-44:54:44.4 |
HIP 22537 |
6.98 |
| 2026-10-01 12:00 |
04:50:23.40 |
-44:54:54.4 |
HIP 22537 |
7.04 |
| 2026-10-02 00:00 |
04:50:22.93 |
-44:55:04.3 |
HIP 22537 |
7.11 |
| 2026-10-02 12:00 |
04:50:22.46 |
-44:55:14.2 |
HIP 22537 |
7.19 |
| 2026-10-03 00:00 |
04:50:21.97 |
-44:55:24.1 |
HIP 22537 |
7.27 |
| 2026-10-03 12:00 |
04:50:21.48 |
-44:55:33.9 |
HIP 22537 |
7.35 |
| 2026-10-04 00:00 |
04:50:20.98 |
-44:55:43.7 |
HIP 22537 |
7.44 |
| 2026-10-04 12:00 |
04:50:20.47 |
-44:55:53.4 |
HIP 22537 |
7.54 |
| 2026-10-05 00:00 |
04:50:19.95 |
-44:56:03.2 |
HIP 22537 |
7.64 |
| 2026-10-05 12:00 |
04:50:19.43 |
-44:56:12.9 |
HIP 22537 |
7.74 |
| 2026-10-06 00:00 |
04:50:18.89 |
-44:56:22.5 |
HIP 22537 |
7.85 |
| 2026-10-06 12:00 |
04:50:18.35 |
-44:56:32.1 |
HIP 22537 |
7.97 |
| 2026-10-07 00:00 |
04:50:17.80 |
-44:56:41.7 |
HIP 22537 |
8.09 |
| 2026-10-07 12:00 |
04:50:17.24 |
-44:56:51.2 |
HIP 22537 |
8.21 |
| 2026-10-08 00:00 |
04:50:16.67 |
-44:57:00.7 |
HIP 22537 |
8.33 |
| 2026-10-08 12:00 |
04:50:16.09 |
-44:57:10.1 |
HIP 22537 |
8.46 |
| 2026-10-09 00:00 |
04:50:15.51 |
-44:57:19.5 |
HIP 22537 |
8.59 |
| 2026-10-09 12:00 |
04:50:14.91 |
-44:57:28.8 |
HIP 22537 |
8.73 |
| 2026-10-10 00:00 |
04:50:14.31 |
-44:57:38.1 |
HIP 22537 |
8.87 |
| 2026-10-10 12:00 |
04:50:13.70 |
-44:57:47.4 |
HIP 22537 |
9.01 |
| 2026-10-11 00:00 |
04:50:13.09 |
-44:57:56.6 |
HIP 22537 |
9.15 |