C/2013 G8 (PANSTARRS)

Metadata

Parameter Value
Designation C/2013 G8 (PANSTARRS)
Type C
Perihelion (tp_cal, UTC) 2013-11-14T23:30:02.741760Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:32:34Z
Obs used 147
NEO -
M1 7.700
K1 11.000
PC 0.030
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2013-09-14.0000000
e 0.99844886
q (au) 5.141176
a (au) 3314.451067
i (deg) 27.615046
Ω (om, deg) 241.021944
ω (w, deg) 80.168493
M (ma, deg) 359.999680

Magnitude

C/2013 G8 (PANSTARRS) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (12.524 + 2.882\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 12.524
n 2.882
gf 0.988
gb -0.652
k 0.800
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 05:50:02.62 +11:15:49.9 HIP 27641 20.49
2026-07-29 12:00 05:50:06.51 +11:15:39.1 HIP 27641 19.94
2026-07-30 00:00 05:50:10.38 +11:15:28.2 HIP 27641 19.42
2026-07-30 12:00 05:50:14.23 +11:15:17.1 HIP 27641 18.95
2026-07-31 00:00 05:50:18.05 +11:15:06.0 HIP 27641 18.51
2026-07-31 12:00 05:50:21.85 +11:14:54.7 HIP 27641 18.13
2026-08-01 00:00 05:50:25.63 +11:14:43.4 HIP 27641 17.79
2026-08-01 12:00 05:50:29.39 +11:14:32.0 HIP 27641 17.49
2026-08-02 00:00 05:50:33.12 +11:14:20.4 HIP 27641 17.25
2026-08-02 12:00 05:50:36.83 +11:14:08.8 HIP 27641 17.06
2026-08-03 00:00 05:50:40.52 +11:13:57.1 HIP 27641 16.93
2026-08-03 12:00 05:50:44.18 +11:13:45.2 HIP 27641 16.84
2026-08-04 00:00 05:50:47.82 +11:13:33.3 HIP 27641 16.81
2026-08-04 12:00 05:50:51.43 +11:13:21.3 HIP 27641 16.83
2026-08-05 00:00 05:50:55.02 +11:13:09.2 HIP 27641 16.90
2026-08-05 12:00 05:50:58.59 +11:12:57.0 HIP 27641 17.02
2026-08-06 00:00 05:51:02.13 +11:12:44.7 HIP 27641 17.19
2026-08-06 12:00 05:51:05.64 +11:12:32.3 HIP 27641 17.40
2026-08-07 00:00 05:51:09.13 +11:12:19.8 HIP 27641 17.66
2026-08-07 12:00 05:51:12.59 +11:12:07.2 HIP 27641 17.96
2026-08-08 00:00 05:51:16.03 +11:11:54.5 HIP 27641 18.29
2026-08-08 12:00 05:51:19.44 +11:11:41.7 HIP 27641 18.66
2026-08-09 00:00 05:51:22.82 +11:11:28.9 HIP 27641 19.06
2026-08-09 12:00 05:51:26.18 +11:11:15.9 HIP 27641 19.49
2026-08-10 00:00 05:51:29.50 +11:11:02.9 HIP 27641 19.95
2026-08-10 12:00 05:51:32.81 +11:10:49.7 HIP 27641 20.43
2026-08-11 00:00 05:51:36.08 +11:10:36.5 HIP 27641 20.93
2026-08-11 12:00 05:51:39.33 +11:10:23.2 HIP 27641 21.45
2026-08-12 00:00 05:51:42.55 +11:10:09.8 HIP 27641 21.99
2026-08-12 12:00 05:51:45.74 +11:09:56.3 HIP 27641 22.54
2026-08-13 00:00 05:51:48.90 +11:09:42.7 HIP 27641 23.11
2026-08-13 12:00 05:51:52.04 +11:09:29.1 HIP 27641 23.69
2026-08-14 00:00 05:51:55.14 +11:09:15.4 HIP 27641 24.27
2026-08-14 12:00 05:51:58.22 +11:09:01.5 HIP 27641 24.87
2026-08-15 00:00 05:52:01.27 +11:08:47.6 HIP 27641 25.48
2026-08-15 12:00 05:52:04.29 +11:08:33.6 HIP 27641 26.09
2026-08-16 00:00 05:52:07.27 +11:08:19.6 HIP 27641 26.70
2026-08-16 12:00 05:52:10.23 +11:08:05.4 HIP 27641 27.32
2026-08-17 00:00 05:52:13.16 +11:07:51.2 HIP 27641 27.95
2026-08-17 12:00 05:52:16.06 +11:07:36.9 HIP 27641 28.57
2026-08-18 00:00 05:52:18.93 +11:07:22.5 HIP 27641 29.20
2026-08-18 12:00 05:52:21.77 +11:07:08.0 HIP 27641 29.83
2026-08-19 00:00 05:52:24.57 +11:06:53.5 HIP 27641 30.47