C/1991 Y1 (Zanotta-Brewington)

メタデータ

項目
Designation C/1991 Y1 (Zanotta-Brewington)
Type C
Perihelion (tp_cal, UTC) 1992-01-31T23:47:40.372800Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:29:41Z
Obs used 266
NEO -
M1 10.200
K1 14.750
PC 0.030
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 1992-01-10.0000000
e 1.00005670
q (au) 0.643969
a (au) -11357.972781
i (deg) 50.028225
Ω (om, deg) 254.908258
ω (w, deg) 197.872524
M (ma, deg) -0.000018

等級

C/1991 Y1 (Zanotta-Brewington) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (9.204 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 9.204
n 2.000
gf 0.800
gb -0.500
k 0.800
δ90 1.000
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
1991-12-23 1992-01-31 +0.0509 +0.039
1992-02-01 1992-05-02 +12.8239 +2.103

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 17:09:14.30 -18:17:33.4 HIP 83850 17.81
2026-07-29 12:00 17:09:12.92 -18:17:33.0 HIP 83850 17.53
2026-07-30 00:00 17:09:11.55 -18:17:32.7 HIP 83850 17.25
2026-07-30 12:00 17:09:10.19 -18:17:32.4 HIP 83850 16.97
2026-07-31 00:00 17:09:08.85 -18:17:32.1 HIP 83850 16.70
2026-07-31 12:00 17:09:07.52 -18:17:31.9 HIP 83850 16.44
2026-08-01 00:00 17:09:06.21 -18:17:31.6 HIP 83850 16.18
2026-08-01 12:00 17:09:04.91 -18:17:31.5 HIP 83850 15.92
2026-08-02 00:00 17:09:03.62 -18:17:31.3 HIP 83850 15.67
2026-08-02 12:00 17:09:02.35 -18:17:31.2 HIP 83850 15.42
2026-08-03 00:00 17:09:01.09 -18:17:31.1 HIP 83850 15.17
2026-08-03 12:00 17:08:59.85 -18:17:31.0 HIP 83850 14.93
2026-08-04 00:00 17:08:58.62 -18:17:31.0 HIP 83850 14.70
2026-08-04 12:00 17:08:57.40 -18:17:30.9 HIP 83850 14.47
2026-08-05 00:00 17:08:56.20 -18:17:31.0 HIP 83850 14.24
2026-08-05 12:00 17:08:55.02 -18:17:31.0 HIP 83850 14.02
2026-08-06 00:00 17:08:53.85 -18:17:31.1 HIP 83850 13.80
2026-08-06 12:00 17:08:52.69 -18:17:31.2 HIP 83850 13.59
2026-08-07 00:00 17:08:51.55 -18:17:31.3 HIP 83850 13.38
2026-08-07 12:00 17:08:50.43 -18:17:31.5 HIP 83850 13.18
2026-08-08 00:00 17:08:49.32 -18:17:31.7 HIP 83850 12.98
2026-08-08 12:00 17:08:48.22 -18:17:31.9 HIP 83850 12.79
2026-08-09 00:00 17:08:47.14 -18:17:32.2 HIP 83850 12.60
2026-08-09 12:00 17:08:46.08 -18:17:32.5 HIP 83850 12.42
2026-08-10 00:00 17:08:45.03 -18:17:32.8 HIP 83850 12.24
2026-08-10 12:00 17:08:44.00 -18:17:33.1 HIP 83850 12.06
2026-08-11 00:00 17:08:42.98 -18:17:33.5 HIP 83850 11.89
2026-08-11 12:00 17:08:41.98 -18:17:33.9 HIP 83850 11.72
2026-08-12 00:00 17:08:40.99 -18:17:34.4 HIP 83850 11.56
2026-08-12 12:00 17:08:40.02 -18:17:34.8 HIP 83850 11.41
2026-08-13 00:00 17:08:39.07 -18:17:35.3 HIP 83850 11.26
2026-08-13 12:00 17:08:38.13 -18:17:35.8 HIP 83850 11.11
2026-08-14 00:00 17:08:37.21 -18:17:36.4 HIP 83850 10.96
2026-08-14 12:00 17:08:36.31 -18:17:37.0 HIP 83850 10.83
2026-08-15 00:00 17:08:35.42 -18:17:37.6 HIP 83850 10.69
2026-08-15 12:00 17:08:34.55 -18:17:38.2 HIP 83850 10.56
2026-08-16 00:00 17:08:33.69 -18:17:38.9 HIP 83850 10.44
2026-08-16 12:00 17:08:32.85 -18:17:39.6 HIP 83850 10.32
2026-08-17 00:00 17:08:32.03 -18:17:40.3 HIP 83850 10.20
2026-08-17 12:00 17:08:31.23 -18:17:41.1 HIP 83850 10.09
2026-08-18 00:00 17:08:30.44 -18:17:41.9 HIP 83850 9.98
2026-08-18 12:00 17:08:29.67 -18:17:42.7 HIP 83850 9.87
2026-08-19 00:00 17:08:28.91 -18:17:43.5 HIP 83850 9.77