C/2008 P1 (Garradd)

メタデータ

項目
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
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
H0 10.382
n 2.000
gf 0.971
gb -0.955
k 1.000
δ90 9.891
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)
2026-03-26 00:00 11:45:34.86 +29:58:14.8 HIP 57395 16.63
2026-03-26 12:00 11:45:31.04 +29:58:25.2 HIP 57395 16.75
2026-03-27 00:00 11:45:27.23 +29:58:35.3 HIP 57239 16.79
2026-03-27 12:00 11:45:23.43 +29:58:45.2 HIP 57239 16.05
2026-03-28 00:00 11:45:19.63 +29:58:54.9 HIP 57239 15.33
2026-03-28 12:00 11:45:15.84 +29:59:04.3 HIP 57239 14.61
2026-03-29 00:00 11:45:12.06 +29:59:13.4 HIP 57239 13.91
2026-03-29 12:00 11:45:08.28 +29:59:22.2 HIP 57239 13.23
2026-03-30 00:00 11:45:04.52 +29:59:30.8 HIP 57239 12.56
2026-03-30 12:00 11:45:00.76 +29:59:39.1 HIP 57239 11.91
2026-03-31 00:00 11:44:57.01 +29:59:47.2 HIP 57239 11.29
2026-03-31 12:00 11:44:53.27 +29:59:55.0 HIP 57239 10.69
2026-04-01 00:00 11:44:49.54 +30:00:02.5 HIP 57239 10.12
2026-04-01 12:00 11:44:45.82 +30:00:09.8 HIP 57239 9.58
2026-04-02 00:00 11:44:42.11 +30:00:16.8 HIP 57239 9.09
2026-04-02 12:00 11:44:38.41 +30:00:23.5 HIP 57239 8.64
2026-04-03 00:00 11:44:34.72 +30:00:30.0 HIP 57239 8.24
2026-04-03 12:00 11:44:31.04 +30:00:36.1 HIP 57239 7.90
2026-04-04 00:00 11:44:27.38 +30:00:42.1 HIP 57239 7.63
2026-04-04 12:00 11:44:23.72 +30:00:47.7 HIP 57239 7.44
2026-04-05 00:00 11:44:20.08 +30:00:53.1 HIP 57239 7.32
2026-04-05 12:00 11:44:16.45 +30:00:58.2 HIP 57239 7.28
2026-04-06 00:00 11:44:12.83 +30:01:03.0 HIP 57239 7.33
2026-04-06 12:00 11:44:09.22 +30:01:07.6 HIP 57239 7.45
2026-04-07 00:00 11:44:05.62 +30:01:11.9 HIP 57239 7.65
2026-04-07 12:00 11:44:02.04 +30:01:15.9 HIP 57239 7.91
2026-04-08 00:00 11:43:58.47 +30:01:19.7 HIP 57239 8.23
2026-04-08 12:00 11:43:54.92 +30:01:23.1 HIP 57239 8.61
2026-04-09 00:00 11:43:51.38 +30:01:26.3 HIP 57239 9.03
2026-04-09 12:00 11:43:47.85 +30:01:29.3 HIP 57239 9.49
2026-04-10 00:00 11:43:44.34 +30:01:31.9 HIP 57239 9.98
2026-04-10 12:00 11:43:40.84 +30:01:34.3 HIP 57239 10.50
2026-04-11 00:00 11:43:37.36 +30:01:36.4 HIP 57239 11.04
2026-04-11 12:00 11:43:33.89 +30:01:38.2 HIP 57239 11.60
2026-04-12 00:00 11:43:30.44 +30:01:39.8 HIP 57239 12.18
2026-04-12 12:00 11:43:27.00 +30:01:41.1 HIP 57239 12.76
2026-04-13 00:00 11:43:23.58 +30:01:42.1 HIP 57239 13.36
2026-04-13 12:00 11:43:20.18 +30:01:42.8 HIP 57239 13.96
2026-04-14 00:00 11:43:16.79 +30:01:43.2 HIP 57239 14.58
2026-04-14 12:00 11:43:13.43 +30:01:43.4 HIP 57239 15.19
2026-04-15 00:00 11:43:10.07 +30:01:43.3 HIP 57239 15.81
2026-04-15 12:00 11:43:06.74 +30:01:42.9 HIP 57239 16.44
2026-04-16 00:00 11:43:03.42 +30:01:42.2 HIP 57239 17.06