C/2008 P1 (Garradd)

メタデータ

項目 値
Designation C/2008 P1 (Garradd)
Type C
Perihelion (tp_cal, UTC) 2009-07-22T22:51:56.433600Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:31:21Z
Obs used 1345
NEO -
M1 11.100
K1 4.500
PC -
オスキュレーティング軌道要素
項目 値
Epoch (epoch_cal, TDB) 2009-08-25.0000000
e 1.00167859
q (au) 3.896111
a (au) -2321.061664
i (deg) 64.310315
Ω (om, deg) 357.676994
ω (w, deg) 11.865464
M (ma, deg) 0.000291

等級

C/2008 P1 (Garradd) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (10.382 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目 値
H0 10.382
n 2.000
gf 0.960
gb -0.747
k 1.000
δ90 9.885
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
2008-08-13 2009-07-21 -8.6915 +4.482
2009-07-23 2011-02-04 +5.2294 -3.081

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 11:46:49.68 +27:52:30.4 HIP 57324 25.94
2026-09-20 12:00 11:46:53.21 +27:52:08.9 HIP 57324 26.78
2026-09-21 00:00 11:46:56.73 +27:51:47.6 HIP 57324 27.62
2026-09-21 12:00 11:47:00.25 +27:51:26.4 HIP 57517 27.95
2026-09-22 00:00 11:47:03.77 +27:51:05.5 HIP 57517 27.49
2026-09-22 12:00 11:47:07.29 +27:50:44.8 HIP 57517 27.06
2026-09-23 00:00 11:47:10.81 +27:50:24.3 HIP 57517 26.65
2026-09-23 12:00 11:47:14.32 +27:50:03.9 HIP 57517 26.26
2026-09-24 00:00 11:47:17.84 +27:49:43.8 HIP 57517 25.90
2026-09-24 12:00 11:47:21.35 +27:49:23.9 HIP 57517 25.56
2026-09-25 00:00 11:47:24.85 +27:49:04.1 HIP 57517 25.25
2026-09-25 12:00 11:47:28.36 +27:48:44.6 HIP 57517 24.97
2026-09-26 00:00 11:47:31.86 +27:48:25.2 HIP 57517 24.72
2026-09-26 12:00 11:47:35.36 +27:48:06.1 HIP 57517 24.50
2026-09-27 00:00 11:47:38.85 +27:47:47.2 HIP 57568 24.27
2026-09-27 12:00 11:47:42.34 +27:47:28.4 HIP 57568 23.83
2026-09-28 00:00 11:47:45.83 +27:47:09.9 HIP 57568 23.41
2026-09-28 12:00 11:47:49.31 +27:46:51.6 HIP 57568 23.01
2026-09-29 00:00 11:47:52.79 +27:46:33.5 HIP 57568 22.65
2026-09-29 12:00 11:47:56.26 +27:46:15.6 HIP 57568 22.31
2026-09-30 00:00 11:47:59.73 +27:45:57.9 HIP 57568 22.00
2026-09-30 12:00 11:48:03.20 +27:45:40.4 HIP 57568 21.72
2026-10-01 00:00 11:48:06.65 +27:45:23.1 HIP 57568 21.47
2026-10-01 12:00 11:48:10.11 +27:45:06.1 HIP 57568 21.25
2026-10-02 00:00 11:48:13.55 +27:44:49.2 HIP 57568 21.07
2026-10-02 12:00 11:48:16.99 +27:44:32.6 HIP 57568 20.91
2026-10-03 00:00 11:48:20.43 +27:44:16.2 HIP 57568 20.80
2026-10-03 12:00 11:48:23.86 +27:44:00.0 HIP 57568 20.71
2026-10-04 00:00 11:48:27.28 +27:43:44.0 HIP 57568 20.67
2026-10-04 12:00 11:48:30.69 +27:43:28.2 HIP 57568 20.65
2026-10-05 00:00 11:48:34.10 +27:43:12.7 HIP 57568 20.67
2026-10-05 12:00 11:48:37.50 +27:42:57.4 HIP 57568 20.72
2026-10-06 00:00 11:48:40.89 +27:42:42.3 HIP 57568 20.81
2026-10-06 12:00 11:48:44.28 +27:42:27.4 HIP 57568 20.93
2026-10-07 00:00 11:48:47.65 +27:42:12.7 HIP 57568 21.08
2026-10-07 12:00 11:48:51.02 +27:41:58.3 HIP 57568 21.26
2026-10-08 00:00 11:48:54.38 +27:41:44.1 HIP 57568 21.47
2026-10-08 12:00 11:48:57.73 +27:41:30.1 HIP 57568 21.70
2026-10-09 00:00 11:49:01.07 +27:41:16.4 HIP 57568 21.97
2026-10-09 12:00 11:49:04.40 +27:41:02.9 HIP 57568 22.26
2026-10-10 00:00 11:49:07.72 +27:40:49.6 HIP 57568 22.57
2026-10-10 12:00 11:49:11.04 +27:40:36.6 HIP 57568 22.91
2026-10-11 00:00 11:49:14.34 +27:40:23.8 HIP 57568 23.26