メタデータ
| 項目 |
値 |
| Designation |
23P/Brorsen-Metcalf |
| Type |
P |
| Perihelion (tp_cal, UTC) |
1989-09-11T22:29:54.219840Z |
| Orbit solution date (soln_date, UTC) |
2002-03-01T13:24:57Z |
| Obs used |
223 |
| NEO |
Yes |
| M1 |
7.800 |
| K1 |
8.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1989-10-01.0000000 |
| e |
0.97195226 |
| q (au) |
0.478753 |
| a (au) |
17.069207 |
| i (deg) |
19.333940 |
| Ω (om, deg) |
311.585462 |
| ω (w, deg) |
129.610684 |
| M (ma, deg) |
0.266419 |
等級
散乱 + 全体線形
$$
M_a = (7.966 + 3.198\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
7.966 |
| n |
3.198 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
1.247 |
| 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 |
| 1989-07-04 |
1989-07-14 |
+67.7705 |
-8.668 |
| 1989-07-14 |
1989-09-11 |
-0.4609 |
-0.069 |
| 1989-09-12 |
2019-02-03 |
-6.3683 |
-1.419 |
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 |
17:21:41.70 |
-38:09:59.5 |
HIP 85022 |
12.03 |
| 2026-07-29 12:00 |
17:21:38.63 |
-38:09:47.0 |
HIP 85022 |
12.66 |
| 2026-07-30 00:00 |
17:21:35.58 |
-38:09:34.5 |
HIP 85022 |
13.29 |
| 2026-07-30 12:00 |
17:21:32.57 |
-38:09:21.9 |
HIP 84865 |
12.70 |
| 2026-07-31 00:00 |
17:21:29.58 |
-38:09:09.3 |
HIP 84865 |
12.12 |
| 2026-07-31 12:00 |
17:21:26.62 |
-38:08:56.6 |
HIP 84865 |
11.54 |
| 2026-08-01 00:00 |
17:21:23.69 |
-38:08:43.8 |
HIP 84865 |
10.97 |
| 2026-08-01 12:00 |
17:21:20.79 |
-38:08:31.0 |
HIP 84865 |
10.41 |
| 2026-08-02 00:00 |
17:21:17.92 |
-38:08:18.1 |
HIP 84865 |
9.86 |
| 2026-08-02 12:00 |
17:21:15.08 |
-38:08:05.1 |
HIP 84865 |
9.32 |
| 2026-08-03 00:00 |
17:21:12.27 |
-38:07:52.1 |
HIP 84865 |
8.79 |
| 2026-08-03 12:00 |
17:21:09.48 |
-38:07:39.1 |
HIP 84865 |
8.27 |
| 2026-08-04 00:00 |
17:21:06.73 |
-38:07:26.0 |
HIP 84865 |
7.77 |
| 2026-08-04 12:00 |
17:21:04.01 |
-38:07:12.8 |
HIP 84865 |
7.27 |
| 2026-08-05 00:00 |
17:21:01.32 |
-38:06:59.6 |
HIP 84865 |
6.80 |
| 2026-08-05 12:00 |
17:20:58.66 |
-38:06:46.4 |
HIP 84865 |
6.34 |
| 2026-08-06 00:00 |
17:20:56.04 |
-38:06:33.1 |
HIP 84865 |
5.91 |
| 2026-08-06 12:00 |
17:20:53.44 |
-38:06:19.7 |
HIP 84865 |
5.49 |
| 2026-08-07 00:00 |
17:20:50.88 |
-38:06:06.3 |
HIP 84865 |
5.11 |
| 2026-08-07 12:00 |
17:20:48.34 |
-38:05:52.9 |
HIP 84865 |
4.76 |
| 2026-08-08 00:00 |
17:20:45.84 |
-38:05:39.4 |
HIP 84865 |
4.46 |
| 2026-08-08 12:00 |
17:20:43.37 |
-38:05:25.9 |
HIP 84865 |
4.20 |
| 2026-08-09 00:00 |
17:20:40.94 |
-38:05:12.3 |
HIP 84865 |
3.99 |
| 2026-08-09 12:00 |
17:20:38.53 |
-38:04:58.7 |
HIP 84865 |
3.84 |
| 2026-08-10 00:00 |
17:20:36.16 |
-38:04:45.0 |
HIP 84865 |
3.76 |
| 2026-08-10 12:00 |
17:20:33.83 |
-38:04:31.3 |
HIP 84865 |
3.75 |
| 2026-08-11 00:00 |
17:20:31.52 |
-38:04:17.6 |
HIP 84865 |
3.80 |
| 2026-08-11 12:00 |
17:20:29.25 |
-38:04:03.8 |
HIP 84865 |
3.91 |
| 2026-08-12 00:00 |
17:20:27.01 |
-38:03:50.0 |
HIP 84865 |
4.08 |
| 2026-08-12 12:00 |
17:20:24.81 |
-38:03:36.2 |
HIP 84865 |
4.29 |
| 2026-08-13 00:00 |
17:20:22.64 |
-38:03:22.3 |
HIP 84865 |
4.54 |
| 2026-08-13 12:00 |
17:20:20.50 |
-38:03:08.5 |
HIP 84865 |
4.81 |
| 2026-08-14 00:00 |
17:20:18.40 |
-38:02:54.5 |
HIP 84865 |
5.12 |
| 2026-08-14 12:00 |
17:20:16.34 |
-38:02:40.6 |
HIP 84865 |
5.44 |
| 2026-08-15 00:00 |
17:20:14.30 |
-38:02:26.6 |
HIP 84865 |
5.77 |
| 2026-08-15 12:00 |
17:20:12.31 |
-38:02:12.6 |
HIP 84865 |
6.11 |
| 2026-08-16 00:00 |
17:20:10.35 |
-38:01:58.6 |
HIP 84865 |
6.47 |
| 2026-08-16 12:00 |
17:20:08.42 |
-38:01:44.5 |
HIP 84865 |
6.82 |
| 2026-08-17 00:00 |
17:20:06.53 |
-38:01:30.4 |
HIP 84865 |
7.18 |
| 2026-08-17 12:00 |
17:20:04.67 |
-38:01:16.3 |
HIP 84865 |
7.54 |
| 2026-08-18 00:00 |
17:20:02.85 |
-38:01:02.2 |
HIP 84745 |
7.67 |
| 2026-08-18 12:00 |
17:20:01.06 |
-38:00:48.1 |
HIP 84745 |
7.29 |
| 2026-08-19 00:00 |
17:19:59.31 |
-38:00:33.9 |
HIP 84745 |
6.94 |