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) |
| 2026-03-26 00:00 |
04:46:29.67 |
-44:41:01.3 |
HIP 22069 |
19.66 |
| 2026-03-26 12:00 |
04:46:30.07 |
-44:40:50.9 |
HIP 22069 |
19.66 |
| 2026-03-27 00:00 |
04:46:30.48 |
-44:40:40.6 |
HIP 22069 |
19.66 |
| 2026-03-27 12:00 |
04:46:30.89 |
-44:40:30.3 |
HIP 22069 |
19.66 |
| 2026-03-28 00:00 |
04:46:31.31 |
-44:40:20.0 |
HIP 22069 |
19.67 |
| 2026-03-28 12:00 |
04:46:31.74 |
-44:40:09.8 |
HIP 22069 |
19.68 |
| 2026-03-29 00:00 |
04:46:32.18 |
-44:39:59.6 |
HIP 22069 |
19.69 |
| 2026-03-29 12:00 |
04:46:32.63 |
-44:39:49.5 |
HIP 22069 |
19.71 |
| 2026-03-30 00:00 |
04:46:33.09 |
-44:39:39.3 |
HIP 22069 |
19.73 |
| 2026-03-30 12:00 |
04:46:33.55 |
-44:39:29.3 |
HIP 22069 |
19.75 |
| 2026-03-31 00:00 |
04:46:34.02 |
-44:39:19.2 |
HIP 22069 |
19.78 |
| 2026-03-31 12:00 |
04:46:34.51 |
-44:39:09.2 |
HIP 22069 |
19.81 |
| 2026-04-01 00:00 |
04:46:35.00 |
-44:38:59.2 |
HIP 22069 |
19.84 |
| 2026-04-01 12:00 |
04:46:35.49 |
-44:38:49.3 |
HIP 22069 |
19.88 |
| 2026-04-02 00:00 |
04:46:36.00 |
-44:38:39.4 |
HIP 22069 |
19.92 |
| 2026-04-02 12:00 |
04:46:36.51 |
-44:38:29.6 |
HIP 22069 |
19.96 |
| 2026-04-03 00:00 |
04:46:37.03 |
-44:38:19.8 |
HIP 22069 |
20.01 |
| 2026-04-03 12:00 |
04:46:37.56 |
-44:38:10.0 |
HIP 22069 |
20.06 |
| 2026-04-04 00:00 |
04:46:38.10 |
-44:38:00.3 |
HIP 22069 |
20.11 |
| 2026-04-04 12:00 |
04:46:38.65 |
-44:37:50.6 |
HIP 22069 |
20.17 |
| 2026-04-05 00:00 |
04:46:39.20 |
-44:37:40.9 |
HIP 22069 |
20.23 |
| 2026-04-05 12:00 |
04:46:39.76 |
-44:37:31.3 |
HIP 22069 |
20.29 |
| 2026-04-06 00:00 |
04:46:40.33 |
-44:37:21.8 |
HIP 22069 |
20.36 |
| 2026-04-06 12:00 |
04:46:40.91 |
-44:37:12.3 |
HIP 22069 |
20.43 |
| 2026-04-07 00:00 |
04:46:41.50 |
-44:37:02.8 |
HIP 22069 |
20.50 |
| 2026-04-07 12:00 |
04:46:42.09 |
-44:36:53.4 |
HIP 22069 |
20.57 |
| 2026-04-08 00:00 |
04:46:42.69 |
-44:36:44.1 |
HIP 22069 |
20.65 |
| 2026-04-08 12:00 |
04:46:43.30 |
-44:36:34.8 |
HIP 22069 |
20.73 |
| 2026-04-09 00:00 |
04:46:43.91 |
-44:36:25.5 |
HIP 22069 |
20.81 |
| 2026-04-09 12:00 |
04:46:44.53 |
-44:36:16.3 |
HIP 22069 |
20.90 |
| 2026-04-10 00:00 |
04:46:45.16 |
-44:36:07.1 |
HIP 22202 |
20.94 |
| 2026-04-10 12:00 |
04:46:45.80 |
-44:35:58.0 |
HIP 22202 |
20.80 |
| 2026-04-11 00:00 |
04:46:46.45 |
-44:35:48.9 |
HIP 22202 |
20.67 |
| 2026-04-11 12:00 |
04:46:47.10 |
-44:35:39.9 |
HIP 22202 |
20.54 |
| 2026-04-12 00:00 |
04:46:47.76 |
-44:35:31.0 |
HIP 22202 |
20.42 |
| 2026-04-12 12:00 |
04:46:48.43 |
-44:35:22.1 |
HIP 22202 |
20.29 |
| 2026-04-13 00:00 |
04:46:49.10 |
-44:35:13.2 |
HIP 22202 |
20.17 |
| 2026-04-13 12:00 |
04:46:49.78 |
-44:35:04.4 |
HIP 22202 |
20.05 |
| 2026-04-14 00:00 |
04:46:50.47 |
-44:34:55.7 |
HIP 22202 |
19.93 |
| 2026-04-14 12:00 |
04:46:51.17 |
-44:34:47.0 |
HIP 22202 |
19.81 |
| 2026-04-15 00:00 |
04:46:51.87 |
-44:34:38.4 |
HIP 22202 |
19.70 |
| 2026-04-15 12:00 |
04:46:52.58 |
-44:34:29.8 |
HIP 22202 |
19.58 |
| 2026-04-16 00:00 |
04:46:53.30 |
-44:34:21.3 |
HIP 22202 |
19.47 |