C/2008 E3 (Garradd)

Metadata

Parameter Value
Designation C/2008 E3 (Garradd)
Type C
Perihelion (tp_cal, UTC) 2008-08-02T05:22:47.424000Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:31:17Z
Obs used 109
NEO -
M1 6.600
K1 10.000
PC 0.030
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2008-08-09.0000000
e 0.99849003
q (au) 5.531015
a (au) 3662.996730
i (deg) 105.076501
Ω (om, deg) 105.674911
ω (w, deg) 218.094534
M (ma, deg) 0.000030

Magnitude

C/2008 E3 (Garradd) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (2.326 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 2.326
n 6.000
gf 1.000
gb -1.000
k 1.000
δ90 10.000
Parameter Symbol Range Description
Absolute magnitude at 1 AU from Sun and Earth H0 -5 to 20 Intrinsic brightness of the comet
Photometric slope parameter n 2 to 6 Rate of brightness change with heliocentric distance
Forward scattering asymmetry factor gf 0.8 to 1 Degree of forward scattering
Backward scattering asymmetry factor gb -1 to -0.5 Degree of backward scattering
Partitioning coefficient k 0.8 to 1 Ratio between forward/backward scattering contributions
Dust-to-gas brightness ratio δ90 1 to 10 Relative contribution of dust scattering to gas emission

Reference: EPSC-DPS2025-160

Ephemeris

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-06-01 00:00 07:09:43.29 +13:24:05.0 HIP 34557 15.40
2026-06-01 12:00 07:09:46.05 +13:24:09.9 HIP 34591 15.43
2026-06-02 00:00 07:09:48.82 +13:24:14.7 HIP 34591 15.44
2026-06-02 12:00 07:09:51.61 +13:24:19.4 HIP 34591 15.48
2026-06-03 00:00 07:09:54.41 +13:24:24.0 HIP 34591 15.55
2026-06-03 12:00 07:09:57.23 +13:24:28.5 HIP 34591 15.64
2026-06-04 00:00 07:10:00.06 +13:24:32.9 HIP 34591 15.76
2026-06-04 12:00 07:10:02.91 +13:24:37.3 HIP 34591 15.92
2026-06-05 00:00 07:10:05.77 +13:24:41.6 HIP 34591 16.10
2026-06-05 12:00 07:10:08.65 +13:24:45.7 HIP 34591 16.30
2026-06-06 00:00 07:10:11.54 +13:24:49.8 HIP 34591 16.54
2026-06-06 12:00 07:10:14.45 +13:24:53.8 HIP 34591 16.80
2026-06-07 00:00 07:10:17.37 +13:24:57.7 HIP 34591 17.09
2026-06-07 12:00 07:10:20.31 +13:25:01.5 HIP 34591 17.40
2026-06-08 00:00 07:10:23.25 +13:25:05.3 HIP 34591 17.73
2026-06-08 12:00 07:10:26.21 +13:25:08.9 HIP 34591 18.09
2026-06-09 00:00 07:10:29.19 +13:25:12.5 HIP 34591 18.47
2026-06-09 12:00 07:10:32.18 +13:25:16.0 HIP 34591 18.86
2026-06-10 00:00 07:10:35.18 +13:25:19.4 HIP 34591 19.28
2026-06-10 12:00 07:10:38.19 +13:25:22.7 HIP 34591 19.72
2026-06-11 00:00 07:10:41.22 +13:25:25.9 HIP 34591 20.18
2026-06-11 12:00 07:10:44.25 +13:25:29.0 HIP 34591 20.65
2026-06-12 00:00 07:10:47.30 +13:25:32.0 HIP 34591 21.14
2026-06-12 12:00 07:10:50.36 +13:25:35.0 HIP 34591 21.64
2026-06-13 00:00 07:10:53.44 +13:25:37.9 HIP 34591 22.16
2026-06-13 12:00 07:10:56.52 +13:25:40.7 HIP 34591 22.69
2026-06-14 00:00 07:10:59.62 +13:25:43.3 HIP 34591 23.23
2026-06-14 12:00 07:11:02.72 +13:25:46.0 HIP 34591 23.79
2026-06-15 00:00 07:11:05.84 +13:25:48.5 HIP 34591 24.36
2026-06-15 12:00 07:11:08.97 +13:25:50.9 HIP 34591 24.94
2026-06-16 00:00 07:11:12.11 +13:25:53.3 HIP 34591 25.53
2026-06-16 12:00 07:11:15.25 +13:25:55.5 HIP 34591 26.13
2026-06-17 00:00 07:11:18.41 +13:25:57.7 HIP 34591 26.74
2026-06-17 12:00 07:11:21.58 +13:25:59.8 HIP 34591 27.36
2026-06-18 00:00 07:11:24.75 +13:26:01.8 HIP 34591 27.98
2026-06-18 12:00 07:11:27.94 +13:26:03.8 HIP 34591 28.62
2026-06-19 00:00 07:11:31.13 +13:26:05.6 HIP 34591 29.26
2026-06-19 12:00 07:11:34.33 +13:26:07.4 HIP 34591 29.91
2026-06-20 00:00 07:11:37.55 +13:26:09.1 HIP 34591 30.57
2026-06-20 12:00 07:11:40.76 +13:26:10.7 HIP 34591 31.23
2026-06-21 00:00 07:11:43.99 +13:26:12.2 HIP 34913 31.16
2026-06-21 12:00 07:11:47.22 +13:26:13.6 HIP 34913 30.54
2026-06-22 00:00 07:11:50.47 +13:26:15.0 HIP 34913 29.92