C/2012 U1 (PANSTARRS)

Metadata

Parameter Value
Designation C/2012 U1 (PANSTARRS)
Type C
Perihelion (tp_cal, UTC) 2014-07-04T17:20:39.560640Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:32:25Z
Obs used 172
NEO -
M1 8.300
K1 10.000
PC 0.030
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2013-12-31.0000000
e 0.99956488
q (au) 5.263903
a (au) 12097.722849
i (deg) 56.339020
Ω (om, deg) 26.982573
ω (w, deg) 70.049903
M (ma, deg) 359.999862

Magnitude

C/2012 U1 (PANSTARRS) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (3.230 + 5.910\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 3.230
n 5.910
gf 1.000
gb -0.501
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 13:48:31.15 -25:39:27.2 HIP 67490 25.27
2026-06-01 12:00 13:48:27.56 -25:39:06.0 HIP 67490 25.58
2026-06-02 00:00 13:48:23.99 -25:38:44.7 HIP 67490 25.92
2026-06-02 12:00 13:48:20.46 -25:38:23.5 HIP 67490 26.28
2026-06-03 00:00 13:48:16.96 -25:38:02.4 HIP 67490 26.66
2026-06-03 12:00 13:48:13.49 -25:37:41.3 HIP 67490 27.06
2026-06-04 00:00 13:48:10.05 -25:37:20.2 HIP 67490 27.47
2026-06-04 12:00 13:48:06.64 -25:36:59.1 HIP 67490 27.90
2026-06-05 00:00 13:48:03.26 -25:36:38.1 HIP 67490 28.33
2026-06-05 12:00 13:47:59.92 -25:36:17.2 HIP 67490 28.79
2026-06-06 00:00 13:47:56.60 -25:35:56.3 HIP 67490 29.25
2026-06-06 12:00 13:47:53.32 -25:35:35.4 HIP 67490 29.72
2026-06-07 00:00 13:47:50.08 -25:35:14.6 HIP 67490 30.20
2026-06-07 12:00 13:47:46.86 -25:34:53.9 HIP 67490 30.69
2026-06-08 00:00 13:47:43.68 -25:34:33.2 HIP 67490 31.18
2026-06-08 12:00 13:47:40.53 -25:34:12.6 HIP 67490 31.69
2026-06-09 00:00 13:47:37.42 -25:33:52.0 HIP 67490 32.19
2026-06-09 12:00 13:47:34.34 -25:33:31.5 HIP 67490 32.70
2026-06-10 00:00 13:47:31.29 -25:33:11.1 HIP 67490 33.22
2026-06-10 12:00 13:47:28.28 -25:32:50.7 HIP 67490 33.73
2026-06-11 00:00 13:47:25.30 -25:32:30.4 HIP 67490 34.25
2026-06-11 12:00 13:47:22.36 -25:32:10.2 HIP 67490 34.77
2026-06-12 00:00 13:47:19.45 -25:31:50.1 HIP 67071 34.73
2026-06-12 12:00 13:47:16.58 -25:31:30.0 HIP 67071 34.07
2026-06-13 00:00 13:47:13.74 -25:31:10.1 HIP 67071 33.42
2026-06-13 12:00 13:47:10.94 -25:30:50.2 HIP 67071 32.78
2026-06-14 00:00 13:47:08.17 -25:30:30.4 HIP 67071 32.15
2026-06-14 12:00 13:47:05.44 -25:30:10.7 HIP 67071 31.53
2026-06-15 00:00 13:47:02.75 -25:29:51.0 HIP 67071 30.92
2026-06-15 12:00 13:47:00.09 -25:29:31.5 HIP 67071 30.33
2026-06-16 00:00 13:46:57.47 -25:29:12.1 HIP 67071 29.75
2026-06-16 12:00 13:46:54.88 -25:28:52.7 HIP 67071 29.18
2026-06-17 00:00 13:46:52.34 -25:28:33.5 HIP 67071 28.62
2026-06-17 12:00 13:46:49.83 -25:28:14.4 HIP 67071 28.07
2026-06-18 00:00 13:46:47.35 -25:27:55.4 HIP 67071 27.54
2026-06-18 12:00 13:46:44.92 -25:27:36.4 HIP 67071 27.02
2026-06-19 00:00 13:46:42.52 -25:27:17.6 HIP 67071 26.51
2026-06-19 12:00 13:46:40.16 -25:26:58.9 HIP 67071 26.01
2026-06-20 00:00 13:46:37.84 -25:26:40.4 HIP 67071 25.53
2026-06-20 12:00 13:46:35.55 -25:26:21.9 HIP 67071 25.07
2026-06-21 00:00 13:46:33.31 -25:26:03.6 HIP 67071 24.61
2026-06-21 12:00 13:46:31.10 -25:25:45.3 HIP 67071 24.17
2026-06-22 00:00 13:46:28.93 -25:25:27.2 HIP 67071 23.75