| 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) |
| 2026-09-20 00:00 |
03:08:24.05 |
+07:04:51.6 |
HIP 14556 |
12.57 |
| 2026-09-20 12:00 |
03:08:21.66 |
+07:04:31.1 |
HIP 14556 |
12.55 |
| 2026-09-21 00:00 |
03:08:19.24 |
+07:04:10.5 |
HIP 14556 |
12.56 |
| 2026-09-21 12:00 |
03:08:16.79 |
+07:03:49.8 |
HIP 14556 |
12.61 |
| 2026-09-22 00:00 |
03:08:14.30 |
+07:03:29.1 |
HIP 14556 |
12.70 |
| 2026-09-22 12:00 |
03:08:11.79 |
+07:03:08.3 |
HIP 14556 |
12.82 |
| 2026-09-23 00:00 |
03:08:09.24 |
+07:02:47.5 |
HIP 14556 |
12.98 |
| 2026-09-23 12:00 |
03:08:06.67 |
+07:02:26.6 |
HIP 14556 |
13.18 |
| 2026-09-24 00:00 |
03:08:04.06 |
+07:02:05.6 |
HIP 14556 |
13.42 |
| 2026-09-24 12:00 |
03:08:01.43 |
+07:01:44.6 |
HIP 14556 |
13.69 |
| 2026-09-25 00:00 |
03:07:58.76 |
+07:01:23.6 |
HIP 14556 |
13.99 |
| 2026-09-25 12:00 |
03:07:56.06 |
+07:01:02.4 |
HIP 14536 |
14.25 |
| 2026-09-26 00:00 |
03:07:53.34 |
+07:00:41.3 |
HIP 14536 |
14.42 |
| 2026-09-26 12:00 |
03:07:50.58 |
+07:00:20.1 |
HIP 14536 |
14.64 |
| 2026-09-27 00:00 |
03:07:47.80 |
+06:59:58.8 |
HIP 14536 |
14.89 |
| 2026-09-27 12:00 |
03:07:44.99 |
+06:59:37.5 |
HIP 14536 |
15.17 |
| 2026-09-28 00:00 |
03:07:42.15 |
+06:59:16.1 |
HIP 14536 |
15.49 |
| 2026-09-28 12:00 |
03:07:39.28 |
+06:58:54.8 |
HIP 14536 |
15.84 |
| 2026-09-29 00:00 |
03:07:36.38 |
+06:58:33.3 |
HIP 14536 |
16.23 |
| 2026-09-29 12:00 |
03:07:33.46 |
+06:58:11.8 |
HIP 14536 |
16.65 |
| 2026-09-30 00:00 |
03:07:30.50 |
+06:57:50.3 |
HIP 14536 |
17.09 |
| 2026-09-30 12:00 |
03:07:27.52 |
+06:57:28.8 |
HIP 14536 |
17.57 |
| 2026-10-01 00:00 |
03:07:24.52 |
+06:57:07.2 |
HIP 14536 |
18.07 |
| 2026-10-01 12:00 |
03:07:21.48 |
+06:56:45.6 |
HIP 14536 |
18.60 |
| 2026-10-02 00:00 |
03:07:18.42 |
+06:56:24.0 |
HIP 14536 |
19.15 |
| 2026-10-02 12:00 |
03:07:15.33 |
+06:56:02.3 |
HIP 14536 |
19.72 |
| 2026-10-03 00:00 |
03:07:12.22 |
+06:55:40.6 |
HIP 14536 |
20.32 |
| 2026-10-03 12:00 |
03:07:09.08 |
+06:55:18.9 |
HIP 14536 |
20.94 |
| 2026-10-04 00:00 |
03:07:05.91 |
+06:54:57.1 |
HIP 14536 |
21.57 |
| 2026-10-04 12:00 |
03:07:02.72 |
+06:54:35.3 |
HIP 14536 |
22.23 |
| 2026-10-05 00:00 |
03:06:59.50 |
+06:54:13.5 |
HIP 14536 |
22.90 |
| 2026-10-05 12:00 |
03:06:56.26 |
+06:53:51.7 |
HIP 14536 |
23.59 |
| 2026-10-06 00:00 |
03:06:53.00 |
+06:53:29.9 |
HIP 14536 |
24.30 |
| 2026-10-06 12:00 |
03:06:49.71 |
+06:53:08.1 |
HIP 14536 |
25.02 |
| 2026-10-07 00:00 |
03:06:46.39 |
+06:52:46.2 |
HIP 14536 |
25.75 |
| 2026-10-07 12:00 |
03:06:43.05 |
+06:52:24.3 |
HIP 14536 |
26.50 |
| 2026-10-08 00:00 |
03:06:39.69 |
+06:52:02.5 |
HIP 14536 |
27.26 |
| 2026-10-08 12:00 |
03:06:36.30 |
+06:51:40.6 |
HIP 14536 |
28.03 |
| 2026-10-09 00:00 |
03:06:32.89 |
+06:51:18.7 |
HIP 14536 |
28.82 |
| 2026-10-09 12:00 |
03:06:29.46 |
+06:50:56.8 |
HIP 14536 |
29.61 |
| 2026-10-10 00:00 |
03:06:26.01 |
+06:50:34.9 |
HIP 14590 |
30.36 |
| 2026-10-10 12:00 |
03:06:22.53 |
+06:50:13.0 |
HIP 14590 |
31.12 |
| 2026-10-11 00:00 |
03:06:19.03 |
+06:49:51.1 |
HIP 14590 |
31.89 |