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) |
| 2026-05-12 00:00 |
17:32:16.89 |
-38:21:04.1 |
HIP 85684 |
22.20 |
| 2026-05-12 12:00 |
17:32:13.18 |
-38:21:09.4 |
HIP 85684 |
21.52 |
| 2026-05-13 00:00 |
17:32:09.46 |
-38:21:14.6 |
HIP 85684 |
20.84 |
| 2026-05-13 12:00 |
17:32:05.71 |
-38:21:19.7 |
HIP 85684 |
20.15 |
| 2026-05-14 00:00 |
17:32:01.94 |
-38:21:24.6 |
HIP 85684 |
19.47 |
| 2026-05-14 12:00 |
17:31:58.15 |
-38:21:29.5 |
HIP 85684 |
18.79 |
| 2026-05-15 00:00 |
17:31:54.34 |
-38:21:34.2 |
HIP 85684 |
18.11 |
| 2026-05-15 12:00 |
17:31:50.51 |
-38:21:38.8 |
HIP 85684 |
17.44 |
| 2026-05-16 00:00 |
17:31:46.66 |
-38:21:43.3 |
HIP 85684 |
16.77 |
| 2026-05-16 12:00 |
17:31:42.79 |
-38:21:47.6 |
HIP 85684 |
16.11 |
| 2026-05-17 00:00 |
17:31:38.90 |
-38:21:51.9 |
HIP 85684 |
15.45 |
| 2026-05-17 12:00 |
17:31:34.99 |
-38:21:56.0 |
HIP 85684 |
14.81 |
| 2026-05-18 00:00 |
17:31:31.06 |
-38:22:00.0 |
HIP 85684 |
14.17 |
| 2026-05-18 12:00 |
17:31:27.11 |
-38:22:03.8 |
HIP 85684 |
13.55 |
| 2026-05-19 00:00 |
17:31:23.14 |
-38:22:07.5 |
HIP 85684 |
12.94 |
| 2026-05-19 12:00 |
17:31:19.16 |
-38:22:11.1 |
HIP 85684 |
12.35 |
| 2026-05-20 00:00 |
17:31:15.15 |
-38:22:14.6 |
HIP 85684 |
11.78 |
| 2026-05-20 12:00 |
17:31:11.14 |
-38:22:18.0 |
HIP 85684 |
11.24 |
| 2026-05-21 00:00 |
17:31:07.10 |
-38:22:21.2 |
HIP 85684 |
10.73 |
| 2026-05-21 12:00 |
17:31:03.05 |
-38:22:24.3 |
HIP 85684 |
10.25 |
| 2026-05-22 00:00 |
17:30:58.98 |
-38:22:27.3 |
HIP 85684 |
9.82 |
| 2026-05-22 12:00 |
17:30:54.89 |
-38:22:30.1 |
HIP 85684 |
9.44 |
| 2026-05-23 00:00 |
17:30:50.79 |
-38:22:32.9 |
HIP 85684 |
9.11 |
| 2026-05-23 12:00 |
17:30:46.67 |
-38:22:35.4 |
HIP 85684 |
8.84 |
| 2026-05-24 00:00 |
17:30:42.54 |
-38:22:37.9 |
HIP 85684 |
8.64 |
| 2026-05-24 12:00 |
17:30:38.40 |
-38:22:40.2 |
HIP 85684 |
8.52 |
| 2026-05-25 00:00 |
17:30:34.24 |
-38:22:42.5 |
HIP 85684 |
8.48 |
| 2026-05-25 12:00 |
17:30:30.07 |
-38:22:44.5 |
HIP 85684 |
8.51 |
| 2026-05-26 00:00 |
17:30:25.88 |
-38:22:46.5 |
HIP 85684 |
8.63 |
| 2026-05-26 12:00 |
17:30:21.68 |
-38:22:48.3 |
HIP 85684 |
8.83 |
| 2026-05-27 00:00 |
17:30:17.47 |
-38:22:50.0 |
HIP 85684 |
9.09 |
| 2026-05-27 12:00 |
17:30:13.24 |
-38:22:51.6 |
HIP 85684 |
9.43 |
| 2026-05-28 00:00 |
17:30:09.01 |
-38:22:53.0 |
HIP 85684 |
9.83 |
| 2026-05-28 12:00 |
17:30:04.76 |
-38:22:54.3 |
HIP 85684 |
10.28 |
| 2026-05-29 00:00 |
17:30:00.50 |
-38:22:55.5 |
HIP 85589 |
10.59 |
| 2026-05-29 12:00 |
17:29:56.22 |
-38:22:56.5 |
HIP 85589 |
10.06 |
| 2026-05-30 00:00 |
17:29:51.94 |
-38:22:57.4 |
HIP 85589 |
9.57 |
| 2026-05-30 12:00 |
17:29:47.65 |
-38:22:58.2 |
HIP 85589 |
9.13 |
| 2026-05-31 00:00 |
17:29:43.35 |
-38:22:58.8 |
HIP 85589 |
8.76 |
| 2026-05-31 12:00 |
17:29:39.03 |
-38:22:59.3 |
HIP 85589 |
8.45 |
| 2026-06-01 00:00 |
17:29:34.71 |
-38:22:59.7 |
HIP 85589 |
8.22 |
| 2026-06-01 12:00 |
17:29:30.38 |
-38:23:00.0 |
HIP 85589 |
8.07 |
| 2026-06-02 00:00 |
17:29:26.04 |
-38:23:00.1 |
HIP 85589 |
8.02 |