| 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) |
| 2026-05-12 00:00 |
02:59:54.48 |
+07:10:57.3 |
HIP 13974 |
5.03 |
| 2026-05-12 12:00 |
02:59:59.29 |
+07:11:16.6 |
HIP 13974 |
5.13 |
| 2026-05-13 00:00 |
03:00:04.10 |
+07:11:35.8 |
HIP 13974 |
5.51 |
| 2026-05-13 12:00 |
03:00:08.91 |
+07:11:54.9 |
HIP 13974 |
6.11 |
| 2026-05-14 00:00 |
03:00:13.71 |
+07:12:13.8 |
HIP 13974 |
6.89 |
| 2026-05-14 12:00 |
03:00:18.52 |
+07:12:32.7 |
HIP 13974 |
7.78 |
| 2026-05-15 00:00 |
03:00:23.31 |
+07:12:51.4 |
HIP 13974 |
8.75 |
| 2026-05-15 12:00 |
03:00:28.11 |
+07:13:10.0 |
HIP 13974 |
9.78 |
| 2026-05-16 00:00 |
03:00:32.89 |
+07:13:28.5 |
HIP 13974 |
10.85 |
| 2026-05-16 12:00 |
03:00:37.68 |
+07:13:46.8 |
HIP 13974 |
11.95 |
| 2026-05-17 00:00 |
03:00:42.46 |
+07:14:05.1 |
HIP 13974 |
13.06 |
| 2026-05-17 12:00 |
03:00:47.23 |
+07:14:23.2 |
HIP 13974 |
14.20 |
| 2026-05-18 00:00 |
03:00:52.00 |
+07:14:41.2 |
HIP 13974 |
15.34 |
| 2026-05-18 12:00 |
03:00:56.76 |
+07:14:59.0 |
HIP 13974 |
16.49 |
| 2026-05-19 00:00 |
03:01:01.51 |
+07:15:16.7 |
HIP 13974 |
17.65 |
| 2026-05-19 12:00 |
03:01:06.26 |
+07:15:34.3 |
HIP 13974 |
18.81 |
| 2026-05-20 00:00 |
03:01:11.00 |
+07:15:51.8 |
HIP 13974 |
19.98 |
| 2026-05-20 12:00 |
03:01:15.74 |
+07:16:09.1 |
HIP 13974 |
21.15 |
| 2026-05-21 00:00 |
03:01:20.46 |
+07:16:26.3 |
HIP 13974 |
22.32 |
| 2026-05-21 12:00 |
03:01:25.18 |
+07:16:43.4 |
HIP 14169 |
23.00 |
| 2026-05-22 00:00 |
03:01:29.89 |
+07:17:00.4 |
HIP 14169 |
22.20 |
| 2026-05-22 12:00 |
03:01:34.59 |
+07:17:17.2 |
HIP 14169 |
21.44 |
| 2026-05-23 00:00 |
03:01:39.29 |
+07:17:33.8 |
HIP 14169 |
20.72 |
| 2026-05-23 12:00 |
03:01:43.97 |
+07:17:50.4 |
HIP 14169 |
20.04 |
| 2026-05-24 00:00 |
03:01:48.65 |
+07:18:06.8 |
HIP 14169 |
19.42 |
| 2026-05-24 12:00 |
03:01:53.32 |
+07:18:23.0 |
HIP 14169 |
18.85 |
| 2026-05-25 00:00 |
03:01:57.97 |
+07:18:39.1 |
HIP 14169 |
18.34 |
| 2026-05-25 12:00 |
03:02:02.62 |
+07:18:55.1 |
HIP 14169 |
17.89 |
| 2026-05-26 00:00 |
03:02:07.26 |
+07:19:11.0 |
HIP 14169 |
17.51 |
| 2026-05-26 12:00 |
03:02:11.89 |
+07:19:26.7 |
HIP 14169 |
17.20 |
| 2026-05-27 00:00 |
03:02:16.50 |
+07:19:42.2 |
HIP 14169 |
16.97 |
| 2026-05-27 12:00 |
03:02:21.11 |
+07:19:57.6 |
HIP 14169 |
16.81 |
| 2026-05-28 00:00 |
03:02:25.70 |
+07:20:12.9 |
HIP 14169 |
16.74 |
| 2026-05-28 12:00 |
03:02:30.29 |
+07:20:28.0 |
HIP 14169 |
16.74 |
| 2026-05-29 00:00 |
03:02:34.86 |
+07:20:43.0 |
HIP 14169 |
16.82 |
| 2026-05-29 12:00 |
03:02:39.42 |
+07:20:57.9 |
HIP 14169 |
16.98 |
| 2026-05-30 00:00 |
03:02:43.97 |
+07:21:12.6 |
HIP 14169 |
17.21 |
| 2026-05-30 12:00 |
03:02:48.50 |
+07:21:27.1 |
HIP 14169 |
17.51 |
| 2026-05-31 00:00 |
03:02:53.02 |
+07:21:41.5 |
HIP 14266 |
16.72 |
| 2026-05-31 12:00 |
03:02:57.53 |
+07:21:55.8 |
HIP 14266 |
15.73 |
| 2026-06-01 00:00 |
03:03:02.03 |
+07:22:09.9 |
HIP 14266 |
14.76 |
| 2026-06-01 12:00 |
03:03:06.52 |
+07:22:23.8 |
HIP 14266 |
13.82 |
| 2026-06-02 00:00 |
03:03:10.99 |
+07:22:37.6 |
HIP 14266 |
12.91 |