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) |
| 2026-09-20 00:00 |
17:19:24.41 |
-37:45:39.7 |
HIP 84745 |
14.56 |
| 2026-09-20 12:00 |
17:19:25.09 |
-37:45:26.7 |
HIP 84745 |
14.78 |
| 2026-09-21 00:00 |
17:19:25.81 |
-37:45:13.7 |
HIP 84745 |
15.00 |
| 2026-09-21 12:00 |
17:19:26.57 |
-37:45:00.7 |
HIP 84745 |
15.22 |
| 2026-09-22 00:00 |
17:19:27.37 |
-37:44:47.9 |
HIP 84745 |
15.44 |
| 2026-09-22 12:00 |
17:19:28.20 |
-37:44:35.0 |
HIP 84745 |
15.66 |
| 2026-09-23 00:00 |
17:19:29.07 |
-37:44:22.2 |
HIP 84745 |
15.88 |
| 2026-09-23 12:00 |
17:19:29.98 |
-37:44:09.5 |
HIP 84745 |
16.10 |
| 2026-09-24 00:00 |
17:19:30.92 |
-37:43:56.8 |
HIP 84745 |
16.33 |
| 2026-09-24 12:00 |
17:19:31.90 |
-37:43:44.2 |
HIP 84745 |
16.56 |
| 2026-09-25 00:00 |
17:19:32.92 |
-37:43:31.6 |
HIP 84745 |
16.78 |
| 2026-09-25 12:00 |
17:19:33.97 |
-37:43:19.1 |
HIP 84745 |
17.01 |
| 2026-09-26 00:00 |
17:19:35.06 |
-37:43:06.7 |
HIP 84745 |
17.24 |
| 2026-09-26 12:00 |
17:19:36.19 |
-37:42:54.3 |
HIP 84745 |
17.48 |
| 2026-09-27 00:00 |
17:19:37.35 |
-37:42:41.9 |
HIP 84745 |
17.71 |
| 2026-09-27 12:00 |
17:19:38.55 |
-37:42:29.7 |
HIP 84745 |
17.95 |
| 2026-09-28 00:00 |
17:19:39.78 |
-37:42:17.5 |
HIP 84745 |
18.19 |
| 2026-09-28 12:00 |
17:19:41.06 |
-37:42:05.3 |
HIP 84745 |
18.44 |
| 2026-09-29 00:00 |
17:19:42.36 |
-37:41:53.2 |
HIP 84745 |
18.68 |
| 2026-09-29 12:00 |
17:19:43.71 |
-37:41:41.2 |
HIP 84745 |
18.93 |
| 2026-09-30 00:00 |
17:19:45.08 |
-37:41:29.2 |
HIP 84745 |
19.18 |
| 2026-09-30 12:00 |
17:19:46.50 |
-37:41:17.3 |
HIP 84745 |
19.44 |
| 2026-10-01 00:00 |
17:19:47.95 |
-37:41:05.5 |
HIP 84745 |
19.70 |
| 2026-10-01 12:00 |
17:19:49.44 |
-37:40:53.7 |
HIP 84745 |
19.96 |
| 2026-10-02 00:00 |
17:19:50.96 |
-37:40:42.0 |
HIP 84745 |
20.23 |
| 2026-10-02 12:00 |
17:19:52.51 |
-37:40:30.4 |
HIP 84745 |
20.49 |
| 2026-10-03 00:00 |
17:19:54.11 |
-37:40:18.8 |
HIP 84745 |
20.77 |
| 2026-10-03 12:00 |
17:19:55.73 |
-37:40:07.3 |
HIP 84745 |
21.04 |
| 2026-10-04 00:00 |
17:19:57.40 |
-37:39:55.9 |
HIP 84745 |
21.32 |
| 2026-10-04 12:00 |
17:19:59.09 |
-37:39:44.6 |
HIP 84745 |
21.61 |
| 2026-10-05 00:00 |
17:20:00.83 |
-37:39:33.3 |
HIP 84745 |
21.90 |
| 2026-10-05 12:00 |
17:20:02.59 |
-37:39:22.1 |
HIP 84745 |
22.19 |
| 2026-10-06 00:00 |
17:20:04.40 |
-37:39:10.9 |
HIP 84745 |
22.49 |
| 2026-10-06 12:00 |
17:20:06.23 |
-37:38:59.9 |
HIP 84745 |
22.79 |
| 2026-10-07 00:00 |
17:20:08.11 |
-37:38:48.9 |
HIP 84745 |
23.10 |
| 2026-10-07 12:00 |
17:20:10.01 |
-37:38:37.9 |
HIP 84745 |
23.41 |
| 2026-10-08 00:00 |
17:20:11.95 |
-37:38:27.1 |
HIP 84865 |
23.59 |
| 2026-10-08 12:00 |
17:20:13.93 |
-37:38:16.3 |
HIP 84865 |
23.67 |
| 2026-10-09 00:00 |
17:20:15.93 |
-37:38:05.6 |
HIP 84865 |
23.75 |
| 2026-10-09 12:00 |
17:20:17.98 |
-37:37:55.0 |
HIP 84865 |
23.83 |
| 2026-10-10 00:00 |
17:20:20.05 |
-37:37:44.5 |
HIP 84865 |
23.93 |
| 2026-10-10 12:00 |
17:20:22.16 |
-37:37:34.0 |
HIP 84865 |
24.02 |
| 2026-10-11 00:00 |
17:20:24.30 |
-37:37:23.6 |
HIP 84865 |
24.12 |