| Parameter |
Value |
| Designation |
C/2012 F3 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-04-06T16:44:17.200320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:06Z |
| Obs used |
1763 |
| NEO |
- |
| M1 |
8.100 |
| K1 |
7.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-11-27.0000000 |
| e |
1.00163676 |
| q (au) |
3.456939 |
| a (au) |
-2112.060187 |
| i (deg) |
11.354698 |
| Ω (om, deg) |
164.617309 |
| ω (w, deg) |
104.020514 |
| M (ma, deg) |
-0.001327 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.830 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.830 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.609 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2012-01-19 |
2015-04-02 |
+2.7355 |
-2.126 |
| 2015-04-10 |
2016-06-05 |
-2.9643 |
+1.982 |
| 2016-06-05 |
2016-09-23 |
-1.7407 |
+1.316 |
| 2016-09-23 |
2017-10-17 |
+7.8916 |
-5.843 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
02:52:48.32 |
+06:35:12.0 |
HIP 13408 |
7.05 |
| 2026-03-26 12:00 |
02:52:52.18 |
+06:35:36.3 |
HIP 13408 |
7.77 |
| 2026-03-27 00:00 |
02:52:56.07 |
+06:36:00.6 |
HIP 13408 |
8.56 |
| 2026-03-27 12:00 |
02:52:59.98 |
+06:36:24.9 |
HIP 13408 |
9.40 |
| 2026-03-28 00:00 |
02:53:03.90 |
+06:36:49.2 |
HIP 13408 |
10.28 |
| 2026-03-28 12:00 |
02:53:07.86 |
+06:37:13.5 |
HIP 13408 |
11.20 |
| 2026-03-29 00:00 |
02:53:11.83 |
+06:37:37.8 |
HIP 13408 |
12.14 |
| 2026-03-29 12:00 |
02:53:15.82 |
+06:38:02.1 |
HIP 13408 |
13.11 |
| 2026-03-30 00:00 |
02:53:19.84 |
+06:38:26.4 |
HIP 13408 |
14.10 |
| 2026-03-30 12:00 |
02:53:23.87 |
+06:38:50.8 |
HIP 13408 |
15.10 |
| 2026-03-31 00:00 |
02:53:27.93 |
+06:39:15.1 |
HIP 13408 |
16.11 |
| 2026-03-31 12:00 |
02:53:32.00 |
+06:39:39.4 |
HIP 13408 |
17.14 |
| 2026-04-01 00:00 |
02:53:36.10 |
+06:40:03.7 |
HIP 13449 |
17.98 |
| 2026-04-01 12:00 |
02:53:40.21 |
+06:40:28.1 |
HIP 13449 |
17.97 |
| 2026-04-02 00:00 |
02:53:44.34 |
+06:40:52.4 |
HIP 13449 |
18.04 |
| 2026-04-02 12:00 |
02:53:48.50 |
+06:41:16.7 |
HIP 13449 |
18.17 |
| 2026-04-03 00:00 |
02:53:52.67 |
+06:41:41.0 |
HIP 13449 |
18.38 |
| 2026-04-03 12:00 |
02:53:56.86 |
+06:42:05.3 |
HIP 13449 |
18.65 |
| 2026-04-04 00:00 |
02:54:01.07 |
+06:42:29.6 |
HIP 13449 |
18.98 |
| 2026-04-04 12:00 |
02:54:05.30 |
+06:42:53.9 |
HIP 13449 |
19.38 |
| 2026-04-05 00:00 |
02:54:09.54 |
+06:43:18.2 |
HIP 13449 |
19.84 |
| 2026-04-05 12:00 |
02:54:13.81 |
+06:43:42.5 |
HIP 13449 |
20.35 |
| 2026-04-06 00:00 |
02:54:18.09 |
+06:44:06.7 |
HIP 13449 |
20.92 |
| 2026-04-06 12:00 |
02:54:22.39 |
+06:44:30.9 |
HIP 13449 |
21.53 |
| 2026-04-07 00:00 |
02:54:26.70 |
+06:44:55.1 |
HIP 13449 |
22.19 |
| 2026-04-07 12:00 |
02:54:31.03 |
+06:45:19.3 |
HIP 13449 |
22.89 |
| 2026-04-08 00:00 |
02:54:35.38 |
+06:45:43.5 |
HIP 13449 |
23.64 |
| 2026-04-08 12:00 |
02:54:39.75 |
+06:46:07.6 |
HIP 13449 |
24.41 |
| 2026-04-09 00:00 |
02:54:44.13 |
+06:46:31.8 |
HIP 13449 |
25.22 |
| 2026-04-09 12:00 |
02:54:48.52 |
+06:46:55.8 |
HIP 13449 |
26.06 |
| 2026-04-10 00:00 |
02:54:52.93 |
+06:47:19.9 |
HIP 13449 |
26.93 |
| 2026-04-10 12:00 |
02:54:57.36 |
+06:47:44.0 |
HIP 13449 |
27.82 |
| 2026-04-11 00:00 |
02:55:01.80 |
+06:48:08.0 |
HIP 13449 |
28.73 |
| 2026-04-11 12:00 |
02:55:06.26 |
+06:48:32.0 |
HIP 13449 |
29.67 |
| 2026-04-12 00:00 |
02:55:10.73 |
+06:48:55.9 |
HIP 13650 |
29.21 |
| 2026-04-12 12:00 |
02:55:15.21 |
+06:49:19.8 |
HIP 13650 |
28.52 |
| 2026-04-13 00:00 |
02:55:19.71 |
+06:49:43.7 |
HIP 13650 |
27.86 |
| 2026-04-13 12:00 |
02:55:24.22 |
+06:50:07.5 |
HIP 13650 |
27.24 |
| 2026-04-14 00:00 |
02:55:28.75 |
+06:50:31.3 |
HIP 13650 |
26.66 |
| 2026-04-14 12:00 |
02:55:33.29 |
+06:50:55.1 |
HIP 13650 |
26.11 |
| 2026-04-15 00:00 |
02:55:37.84 |
+06:51:18.8 |
HIP 13650 |
25.62 |
| 2026-04-15 12:00 |
02:55:42.40 |
+06:51:42.5 |
HIP 13650 |
25.17 |
| 2026-04-16 00:00 |
02:55:46.98 |
+06:52:06.1 |
HIP 13650 |
24.77 |