| Parameter |
Value |
| Designation |
C/2014 F3 (Sheppard-Trujillo) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-05-18T09:14:56.149440Z |
| Orbit solution date (soln_date, UTC) |
2025-01-10T09:12:14Z |
| Obs used |
100 |
| NEO |
- |
| M1 |
14.400 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-09-10.0000000 |
| e |
0.64217219 |
| q (au) |
5.704144 |
| a (au) |
15.941031 |
| i (deg) |
6.568810 |
| Ω (om, deg) |
326.803827 |
| ω (w, deg) |
2.927768 |
| M (ma, deg) |
356.122619 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.814 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.814 |
| n |
2.000 |
| gf |
0.887 |
| gb |
-0.936 |
| k |
1.000 |
| δ90 |
3.631 |
| 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 |
| 2014-03-26 |
2020-09-16 |
-6.4566 |
+5.035 |
| 2021-07-09 |
2024-11-25 |
-15.6318 |
+11.981 |
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 |
05:24:30.50 |
+29:21:43.7 |
HIP 25158 |
25.53 |
| 2026-09-20 12:00 |
05:24:32.42 |
+29:22:00.4 |
HIP 25158 |
26.03 |
| 2026-09-21 00:00 |
05:24:34.23 |
+29:22:17.1 |
HIP 25158 |
26.52 |
| 2026-09-21 12:00 |
05:24:35.95 |
+29:22:33.6 |
HIP 25158 |
26.98 |
| 2026-09-22 00:00 |
05:24:37.56 |
+29:22:50.0 |
HIP 25158 |
27.42 |
| 2026-09-22 12:00 |
05:24:39.06 |
+29:23:06.4 |
HIP 25158 |
27.85 |
| 2026-09-23 00:00 |
05:24:40.46 |
+29:23:22.7 |
HIP 25158 |
28.26 |
| 2026-09-23 12:00 |
05:24:41.76 |
+29:23:38.9 |
HIP 25158 |
28.65 |
| 2026-09-24 00:00 |
05:24:42.95 |
+29:23:55.0 |
HIP 25158 |
29.02 |
| 2026-09-24 12:00 |
05:24:44.04 |
+29:24:11.0 |
HIP 25158 |
29.37 |
| 2026-09-25 00:00 |
05:24:45.03 |
+29:24:27.0 |
HIP 25158 |
29.71 |
| 2026-09-25 12:00 |
05:24:45.91 |
+29:24:42.8 |
HIP 25157 |
29.85 |
| 2026-09-26 00:00 |
05:24:46.69 |
+29:24:58.6 |
HIP 25157 |
29.81 |
| 2026-09-26 12:00 |
05:24:47.36 |
+29:25:14.2 |
HIP 25157 |
29.76 |
| 2026-09-27 00:00 |
05:24:47.93 |
+29:25:29.8 |
HIP 25157 |
29.70 |
| 2026-09-27 12:00 |
05:24:48.40 |
+29:25:45.3 |
HIP 25157 |
29.62 |
| 2026-09-28 00:00 |
05:24:48.76 |
+29:26:00.6 |
HIP 25157 |
29.53 |
| 2026-09-28 12:00 |
05:24:49.01 |
+29:26:15.9 |
HIP 25157 |
29.42 |
| 2026-09-29 00:00 |
05:24:49.17 |
+29:26:31.1 |
HIP 25157 |
29.30 |
| 2026-09-29 12:00 |
05:24:49.21 |
+29:26:46.2 |
HIP 25157 |
29.16 |
| 2026-09-30 00:00 |
05:24:49.15 |
+29:27:01.1 |
HIP 25157 |
29.00 |
| 2026-09-30 12:00 |
05:24:48.99 |
+29:27:16.0 |
HIP 25157 |
28.83 |
| 2026-10-01 00:00 |
05:24:48.72 |
+29:27:30.8 |
HIP 25157 |
28.64 |
| 2026-10-01 12:00 |
05:24:48.35 |
+29:27:45.4 |
HIP 25157 |
28.44 |
| 2026-10-02 00:00 |
05:24:47.88 |
+29:28:00.0 |
HIP 25157 |
28.21 |
| 2026-10-02 12:00 |
05:24:47.29 |
+29:28:14.4 |
HIP 25157 |
27.98 |
| 2026-10-03 00:00 |
05:24:46.61 |
+29:28:28.7 |
HIP 25157 |
27.72 |
| 2026-10-03 12:00 |
05:24:45.81 |
+29:28:42.9 |
HIP 25157 |
27.44 |
| 2026-10-04 00:00 |
05:24:44.92 |
+29:28:57.0 |
HIP 25157 |
27.15 |
| 2026-10-04 12:00 |
05:24:43.92 |
+29:29:11.0 |
HIP 25157 |
26.84 |
| 2026-10-05 00:00 |
05:24:42.81 |
+29:29:24.9 |
HIP 25157 |
26.51 |
| 2026-10-05 12:00 |
05:24:41.60 |
+29:29:38.6 |
HIP 25157 |
26.17 |
| 2026-10-06 00:00 |
05:24:40.28 |
+29:29:52.3 |
HIP 25157 |
25.81 |
| 2026-10-06 12:00 |
05:24:38.86 |
+29:30:05.8 |
HIP 25157 |
25.42 |
| 2026-10-07 00:00 |
05:24:37.33 |
+29:30:19.2 |
HIP 25157 |
25.02 |
| 2026-10-07 12:00 |
05:24:35.70 |
+29:30:32.4 |
HIP 25157 |
24.61 |
| 2026-10-08 00:00 |
05:24:33.96 |
+29:30:45.6 |
HIP 25157 |
24.17 |
| 2026-10-08 12:00 |
05:24:32.12 |
+29:30:58.6 |
HIP 25157 |
23.72 |
| 2026-10-09 00:00 |
05:24:30.18 |
+29:31:11.4 |
HIP 25157 |
23.24 |
| 2026-10-09 12:00 |
05:24:28.13 |
+29:31:24.2 |
HIP 25157 |
22.75 |
| 2026-10-10 00:00 |
05:24:25.98 |
+29:31:36.8 |
HIP 25157 |
22.25 |
| 2026-10-10 12:00 |
05:24:23.72 |
+29:31:49.2 |
HIP 25157 |
21.72 |
| 2026-10-11 00:00 |
05:24:21.36 |
+29:32:01.6 |
HIP 25157 |
21.18 |