| Parameter |
Value |
| Designation |
C/2017 U2 (Fuls) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-08-28T02:57:59.221440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:37Z |
| Obs used |
59 |
| NEO |
- |
| M1 |
7.300 |
| K1 |
12.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-12-10.0000000 |
| e |
1.00001237 |
| q (au) |
6.700825 |
| a (au) |
-541554.498455 |
| i (deg) |
95.434086 |
| Ω (om, deg) |
149.710839 |
| ω (w, deg) |
147.727081 |
| M (ma, deg) |
0.000000 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.858 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.858 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-1.000 |
| k |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
02:42:48.67 |
-72:41:46.8 |
HIP 12960 |
22.19 |
| 2026-03-26 12:00 |
02:43:08.00 |
-72:40:54.5 |
HIP 12960 |
21.71 |
| 2026-03-27 00:00 |
02:43:27.40 |
-72:40:02.7 |
HIP 12960 |
21.33 |
| 2026-03-27 12:00 |
02:43:46.86 |
-72:39:11.4 |
HIP 12960 |
21.07 |
| 2026-03-28 00:00 |
02:44:06.40 |
-72:38:20.7 |
HIP 12960 |
20.93 |
| 2026-03-28 12:00 |
02:44:26.01 |
-72:37:30.4 |
HIP 12960 |
20.91 |
| 2026-03-29 00:00 |
02:44:45.68 |
-72:36:40.7 |
HIP 12960 |
21.01 |
| 2026-03-29 12:00 |
02:45:05.43 |
-72:35:51.5 |
HIP 12960 |
21.24 |
| 2026-03-30 00:00 |
02:45:25.23 |
-72:35:02.9 |
HIP 12960 |
21.58 |
| 2026-03-30 12:00 |
02:45:45.11 |
-72:34:14.7 |
HIP 12960 |
22.04 |
| 2026-03-31 00:00 |
02:46:05.05 |
-72:33:27.1 |
HIP 12960 |
22.60 |
| 2026-03-31 12:00 |
02:46:25.05 |
-72:32:40.1 |
HIP 12960 |
23.26 |
| 2026-04-01 00:00 |
02:46:45.12 |
-72:31:53.5 |
HIP 13227 |
23.59 |
| 2026-04-01 12:00 |
02:47:05.25 |
-72:31:07.5 |
HIP 13227 |
23.21 |
| 2026-04-02 00:00 |
02:47:25.44 |
-72:30:22.0 |
HIP 13227 |
22.94 |
| 2026-04-02 12:00 |
02:47:45.69 |
-72:29:37.1 |
HIP 13227 |
22.78 |
| 2026-04-03 00:00 |
02:48:06.00 |
-72:28:52.7 |
HIP 13227 |
22.73 |
| 2026-04-03 12:00 |
02:48:26.38 |
-72:28:08.8 |
HIP 13227 |
22.79 |
| 2026-04-04 00:00 |
02:48:46.81 |
-72:27:25.5 |
HIP 13227 |
22.97 |
| 2026-04-04 12:00 |
02:49:07.30 |
-72:26:42.7 |
HIP 13227 |
23.26 |
| 2026-04-05 00:00 |
02:49:27.85 |
-72:26:00.5 |
HIP 13227 |
23.66 |
| 2026-04-05 12:00 |
02:49:48.45 |
-72:25:18.8 |
HIP 13227 |
24.15 |
| 2026-04-06 00:00 |
02:50:09.11 |
-72:24:37.6 |
HIP 13227 |
24.75 |
| 2026-04-06 12:00 |
02:50:29.83 |
-72:23:57.1 |
HIP 13227 |
25.43 |
| 2026-04-07 00:00 |
02:50:50.60 |
-72:23:17.0 |
HIP 13227 |
26.19 |
| 2026-04-07 12:00 |
02:51:11.43 |
-72:22:37.5 |
HIP 13227 |
27.04 |
| 2026-04-08 00:00 |
02:51:32.30 |
-72:21:58.6 |
HIP 13227 |
27.95 |
| 2026-04-08 12:00 |
02:51:53.24 |
-72:21:20.3 |
HIP 13227 |
28.92 |
| 2026-04-09 00:00 |
02:52:14.22 |
-72:20:42.5 |
HIP 13227 |
29.95 |
| 2026-04-09 12:00 |
02:52:35.25 |
-72:20:05.2 |
HIP 13227 |
31.03 |
| 2026-04-10 00:00 |
02:52:56.34 |
-72:19:28.5 |
HIP 13928 |
31.42 |
| 2026-04-10 12:00 |
02:53:17.48 |
-72:18:52.4 |
HIP 13928 |
30.15 |
| 2026-04-11 00:00 |
02:53:38.66 |
-72:18:16.9 |
HIP 13928 |
28.92 |
| 2026-04-11 12:00 |
02:53:59.89 |
-72:17:41.9 |
HIP 13928 |
27.74 |
| 2026-04-12 00:00 |
02:54:21.17 |
-72:17:07.5 |
HIP 13928 |
26.60 |
| 2026-04-12 12:00 |
02:54:42.50 |
-72:16:33.7 |
HIP 13928 |
25.51 |
| 2026-04-13 00:00 |
02:55:03.88 |
-72:16:00.4 |
HIP 13928 |
24.49 |
| 2026-04-13 12:00 |
02:55:25.30 |
-72:15:27.8 |
HIP 13928 |
23.53 |
| 2026-04-14 00:00 |
02:55:46.76 |
-72:14:55.7 |
HIP 13928 |
22.66 |
| 2026-04-14 12:00 |
02:56:08.27 |
-72:14:24.2 |
HIP 13928 |
21.87 |
| 2026-04-15 00:00 |
02:56:29.82 |
-72:13:53.2 |
HIP 13928 |
21.18 |
| 2026-04-15 12:00 |
02:56:51.41 |
-72:13:22.9 |
HIP 13928 |
20.60 |
| 2026-04-16 00:00 |
02:57:13.05 |
-72:12:53.1 |
HIP 13928 |
20.14 |