C/2008 J5 (Garradd)

Metadata

Parameter Value
Designation C/2008 J5 (Garradd)
Type C
Perihelion (tp_cal, UTC) 2008-04-01T01:47:02.302080Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:31:19Z
Obs used 128
NEO -
M1 10.600
K1 17.000
PC 0.030
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2008-06-25.0000000
e 0.97288948
q (au) 1.963842
a (au) 72.438378
i (deg) 93.270724
Ω (om, deg) 287.075696
ω (w, deg) 313.376402
M (ma, deg) 0.135766

Magnitude

C/2008 J5 (Garradd) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (10.954 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 10.954
n 6.000
gf 1.000
gb -0.798
k 0.998
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)
2026-07-29 00:00 13:36:47.77 +79:34:50.5 HIP 66373 10.53
2026-07-29 12:00 13:36:49.81 +79:34:02.3 HIP 66373 9.75
2026-07-30 00:00 13:36:51.99 +79:33:14.1 HIP 66373 8.96
2026-07-30 12:00 13:36:54.30 +79:32:26.0 HIP 66373 8.19
2026-07-31 00:00 13:36:56.75 +79:31:38.0 HIP 66373 7.43
2026-07-31 12:00 13:36:59.33 +79:30:50.1 HIP 66373 6.68
2026-08-01 00:00 13:37:02.04 +79:30:02.3 HIP 66373 5.94
2026-08-01 12:00 13:37:04.88 +79:29:14.5 HIP 66373 5.24
2026-08-02 00:00 13:37:07.86 +79:28:26.8 HIP 66373 4.57
2026-08-02 12:00 13:37:10.96 +79:27:39.3 HIP 66373 3.95
2026-08-03 00:00 13:37:14.20 +79:26:51.8 HIP 66373 3.43
2026-08-03 12:00 13:37:17.57 +79:26:04.4 HIP 66373 3.03
2026-08-04 00:00 13:37:21.06 +79:25:17.2 HIP 66373 2.82
2026-08-04 12:00 13:37:24.68 +79:24:30.0 HIP 66373 2.84
2026-08-05 00:00 13:37:28.43 +79:23:43.0 HIP 66373 3.08
2026-08-05 12:00 13:37:32.31 +79:22:56.0 HIP 66393 2.74
2026-08-06 00:00 13:37:36.31 +79:22:09.2 HIP 66393 2.51
2026-08-06 12:00 13:37:40.44 +79:21:22.5 HIP 66393 2.53
2026-08-07 00:00 13:37:44.69 +79:20:35.9 HIP 66393 2.79
2026-08-07 12:00 13:37:49.07 +79:19:49.5 HIP 66393 3.24
2026-08-08 00:00 13:37:53.57 +79:19:03.1 HIP 66393 3.81
2026-08-08 12:00 13:37:58.19 +79:18:16.9 HIP 66393 4.46
2026-08-09 00:00 13:38:02.94 +79:17:30.8 HIP 66393 5.15
2026-08-09 12:00 13:38:07.81 +79:16:44.9 HIP 66393 5.87
2026-08-10 00:00 13:38:12.80 +79:15:59.1 HIP 66393 6.61
2026-08-10 12:00 13:38:17.91 +79:15:13.4 HIP 66393 7.37
2026-08-11 00:00 13:38:23.13 +79:14:27.9 HIP 66393 8.13
2026-08-11 12:00 13:38:28.48 +79:13:42.6 HIP 66393 8.90
2026-08-12 00:00 13:38:33.95 +79:12:57.4 HIP 66393 9.68
2026-08-12 12:00 13:38:39.53 +79:12:12.3 HIP 66393 10.46
2026-08-13 00:00 13:38:45.23 +79:11:27.4 HIP 66393 11.24
2026-08-13 12:00 13:38:51.04 +79:10:42.7 HIP 66393 12.02
2026-08-14 00:00 13:38:56.97 +79:09:58.1 HIP 66393 12.81
2026-08-14 12:00 13:39:03.01 +79:09:13.7 HIP 66393 13.60
2026-08-15 00:00 13:39:09.17 +79:08:29.4 HIP 66393 14.38
2026-08-15 12:00 13:39:15.43 +79:07:45.4 HIP 66393 15.17
2026-08-16 00:00 13:39:21.81 +79:07:01.5 HIP 66393 15.96
2026-08-16 12:00 13:39:28.30 +79:06:17.8 HIP 66393 16.75
2026-08-17 00:00 13:39:34.90 +79:05:34.3 HIP 66393 17.54
2026-08-17 12:00 13:39:41.61 +79:04:50.9 HIP 66393 18.32
2026-08-18 00:00 13:39:48.43 +79:04:07.8 HIP 66393 19.11
2026-08-18 12:00 13:39:55.35 +79:03:24.8 HIP 66393 19.90
2026-08-19 00:00 13:40:02.38 +79:02:42.0 HIP 66393 20.69