| 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) |
| 2026-03-26 00:00 |
04:17:43.41 |
+27:28:00.7 |
HIP 20250 |
35.71 |
| 2026-03-26 12:00 |
04:17:52.88 |
+27:28:06.1 |
HIP 20250 |
33.67 |
| 2026-03-27 00:00 |
04:18:02.42 |
+27:28:11.9 |
HIP 20250 |
31.62 |
| 2026-03-27 12:00 |
04:18:12.04 |
+27:28:17.8 |
HIP 20250 |
29.57 |
| 2026-03-28 00:00 |
04:18:21.73 |
+27:28:24.0 |
HIP 20250 |
27.52 |
| 2026-03-28 12:00 |
04:18:31.50 |
+27:28:30.4 |
HIP 20250 |
25.47 |
| 2026-03-29 00:00 |
04:18:41.34 |
+27:28:37.0 |
HIP 20250 |
23.42 |
| 2026-03-29 12:00 |
04:18:51.25 |
+27:28:43.9 |
HIP 20250 |
21.39 |
| 2026-03-30 00:00 |
04:19:01.23 |
+27:28:51.0 |
HIP 20250 |
19.39 |
| 2026-03-30 12:00 |
04:19:11.29 |
+27:28:58.3 |
HIP 20250 |
17.42 |
| 2026-03-31 00:00 |
04:19:21.41 |
+27:29:05.8 |
HIP 20250 |
15.52 |
| 2026-03-31 12:00 |
04:19:31.61 |
+27:29:13.5 |
HIP 20250 |
13.71 |
| 2026-04-01 00:00 |
04:19:41.87 |
+27:29:21.5 |
HIP 20250 |
12.05 |
| 2026-04-01 12:00 |
04:19:52.21 |
+27:29:29.7 |
HIP 20250 |
10.62 |
| 2026-04-02 00:00 |
04:20:02.61 |
+27:29:38.1 |
HIP 20250 |
9.52 |
| 2026-04-02 12:00 |
04:20:13.08 |
+27:29:46.7 |
HIP 20250 |
8.91 |
| 2026-04-03 00:00 |
04:20:23.62 |
+27:29:55.5 |
HIP 20250 |
8.88 |
| 2026-04-03 12:00 |
04:20:34.23 |
+27:30:04.5 |
HIP 20250 |
9.47 |
| 2026-04-04 00:00 |
04:20:44.91 |
+27:30:13.8 |
HIP 20250 |
10.57 |
| 2026-04-04 12:00 |
04:20:55.65 |
+27:30:23.2 |
HIP 20324 |
10.33 |
| 2026-04-05 00:00 |
04:21:06.45 |
+27:30:32.8 |
HIP 20324 |
9.73 |
| 2026-04-05 12:00 |
04:21:17.32 |
+27:30:42.7 |
HIP 20324 |
9.71 |
| 2026-04-06 00:00 |
04:21:28.26 |
+27:30:52.7 |
HIP 20324 |
10.28 |
| 2026-04-06 12:00 |
04:21:39.26 |
+27:31:03.0 |
HIP 20324 |
11.36 |
| 2026-04-07 00:00 |
04:21:50.32 |
+27:31:13.4 |
HIP 20324 |
12.83 |
| 2026-04-07 12:00 |
04:22:01.44 |
+27:31:24.1 |
HIP 20324 |
14.59 |
| 2026-04-08 00:00 |
04:22:12.63 |
+27:31:34.9 |
HIP 20324 |
16.54 |
| 2026-04-08 12:00 |
04:22:23.88 |
+27:31:45.9 |
HIP 20324 |
18.64 |
| 2026-04-09 00:00 |
04:22:35.20 |
+27:31:57.1 |
HIP 20324 |
20.84 |
| 2026-04-09 12:00 |
04:22:46.57 |
+27:32:08.5 |
HIP 20528 |
22.95 |
| 2026-04-10 00:00 |
04:22:58.00 |
+27:32:20.1 |
HIP 20528 |
21.21 |
| 2026-04-10 12:00 |
04:23:09.49 |
+27:32:31.9 |
HIP 20528 |
19.63 |
| 2026-04-11 00:00 |
04:23:21.05 |
+27:32:43.9 |
HIP 20528 |
18.26 |
| 2026-04-11 12:00 |
04:23:32.66 |
+27:32:56.0 |
HIP 20528 |
17.16 |
| 2026-04-12 00:00 |
04:23:44.33 |
+27:33:08.4 |
HIP 20528 |
16.39 |
| 2026-04-12 12:00 |
04:23:56.06 |
+27:33:20.9 |
HIP 20528 |
16.01 |
| 2026-04-13 00:00 |
04:24:07.84 |
+27:33:33.6 |
HIP 20528 |
16.05 |
| 2026-04-13 12:00 |
04:24:19.68 |
+27:33:46.5 |
HIP 20528 |
16.50 |
| 2026-04-14 00:00 |
04:24:31.58 |
+27:33:59.5 |
HIP 20528 |
17.35 |
| 2026-04-14 12:00 |
04:24:43.53 |
+27:34:12.7 |
HIP 20528 |
18.55 |
| 2026-04-15 00:00 |
04:24:55.54 |
+27:34:26.1 |
HIP 20528 |
20.04 |
| 2026-04-15 12:00 |
04:25:07.60 |
+27:34:39.7 |
HIP 20528 |
21.75 |
| 2026-04-16 00:00 |
04:25:19.72 |
+27:34:53.4 |
HIP 20528 |
23.66 |