P/2012 B1 (PANSTARRS)

Metadata

Parameter Value
Designation P/2012 B1 (PANSTARRS)
Type P
Perihelion (tp_cal, UTC) 2013-07-23T03:26:57.641280Z
Orbit solution date (soln_date, UTC) 2022-05-19T21:13:35Z
Obs used 1189
NEO -
M1 6.400
K1 12.750
PC 0.030
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2013-02-05.0000000
e 0.41050358
q (au) 3.825153
a (au) 6.488848
i (deg) 7.627784
Ω (om, deg) 36.194183
ω (w, deg) 162.183007
M (ma, deg) 349.973869

Magnitude

P/2012 B1 (PANSTARRS) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (3.981 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 3.981
n 6.000
gf 1.000
gb -0.500
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

Residuals (Piecewise)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

Start (UTC) End (UTC) a b
2011-12-31 2013-07-20 +5.5281 -3.279
2013-08-25 2015-06-10 +9.6303 -6.962

log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)

Ephemeris

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-07-29 00:00 05:15:38.46 +27:20:58.2 HIP 24546 13.92
2026-07-29 12:00 05:15:56.03 +27:21:35.5 HIP 24546 13.91
2026-07-30 00:00 05:16:13.54 +27:22:12.8 HIP 24546 14.99
2026-07-30 12:00 05:16:30.98 +27:22:50.0 HIP 24581 16.40
2026-07-31 00:00 05:16:48.34 +27:23:27.1 HIP 24581 17.72
2026-07-31 12:00 05:17:05.64 +27:24:04.1 HIP 24581 19.73
2026-08-01 00:00 05:17:22.87 +27:24:41.1 HIP 24647 21.24
2026-08-01 12:00 05:17:40.03 +27:25:18.0 HIP 24647 21.06
2026-08-02 00:00 05:17:57.12 +27:25:54.8 HIP 24647 21.58
2026-08-02 12:00 05:18:14.13 +27:26:31.6 HIP 24647 22.73
2026-08-03 00:00 05:18:31.07 +27:27:08.3 HIP 24647 24.41
2026-08-03 12:00 05:18:47.93 +27:27:44.9 HIP 24896 21.37
2026-08-04 00:00 05:19:04.73 +27:28:21.5 HIP 24896 17.92
2026-08-04 12:00 05:19:21.44 +27:28:58.0 HIP 24896 14.65
2026-08-05 00:00 05:19:38.08 +27:29:34.4 HIP 24896 11.68
2026-08-05 12:00 05:19:54.64 +27:30:10.8 HIP 24896 9.29
2026-08-06 00:00 05:20:11.13 +27:30:47.1 HIP 24896 7.99
2026-08-06 12:00 05:20:27.53 +27:31:23.3 HIP 24896 8.29
2026-08-07 00:00 05:20:43.86 +27:31:59.5 HIP 24896 10.03
2026-08-07 12:00 05:21:00.10 +27:32:35.6 HIP 24896 12.60
2026-08-08 00:00 05:21:16.27 +27:33:11.7 HIP 24896 15.60
2026-08-08 12:00 05:21:32.35 +27:33:47.7 HIP 24896 18.80
2026-08-09 00:00 05:21:48.35 +27:34:23.6 HIP 24896 22.11
2026-08-09 12:00 05:22:04.26 +27:34:59.5 HIP 24896 25.48
2026-08-10 00:00 05:22:20.09 +27:35:35.3 HIP 24984 28.22
2026-08-10 12:00 05:22:35.83 +27:36:11.1 HIP 25112 29.93
2026-08-11 00:00 05:22:51.49 +27:36:46.8 HIP 25112 29.56
2026-08-11 12:00 05:23:07.05 +27:37:22.5 HIP 25112 29.61
2026-08-12 00:00 05:23:22.53 +27:37:58.1 HIP 25112 30.06
2026-08-12 12:00 05:23:37.92 +27:38:33.7 HIP 25112 30.88
2026-08-13 00:00 05:23:53.22 +27:39:09.2 HIP 25112 32.05
2026-08-13 12:00 05:24:08.43 +27:39:44.6 HIP 25112 33.52
2026-08-14 00:00 05:24:23.54 +27:40:20.0 HIP 25484 35.14
2026-08-14 12:00 05:24:38.57 +27:40:55.4 HIP 25484 31.91
2026-08-15 00:00 05:24:53.50 +27:41:30.7 HIP 25484 28.73
2026-08-15 12:00 05:25:08.33 +27:42:05.9 HIP 25484 25.61
2026-08-16 00:00 05:25:23.07 +27:42:41.2 HIP 25484 22.59
2026-08-16 12:00 05:25:37.71 +27:43:16.3 HIP 25484 19.67
2026-08-17 00:00 05:25:52.26 +27:43:51.5 HIP 25484 16.92
2026-08-17 12:00 05:26:06.71 +27:44:26.5 HIP 25484 14.40
2026-08-18 00:00 05:26:21.06 +27:45:01.6 HIP 25484 12.25
2026-08-18 12:00 05:26:35.31 +27:45:36.6 HIP 25484 10.68
2026-08-19 00:00 05:26:49.46 +27:46:11.5 HIP 25484 9.93