| 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 |
1.000 |
| gb |
-0.502 |
| 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) |
| 2026-06-01 00:00 |
03:31:41.82 |
-72:10:16.0 |
HIP 16392 |
12.44 |
| 2026-06-01 12:00 |
03:32:04.13 |
-72:10:42.3 |
HIP 16392 |
12.52 |
| 2026-06-02 00:00 |
03:32:26.41 |
-72:11:09.2 |
HIP 16392 |
12.83 |
| 2026-06-02 12:00 |
03:32:48.67 |
-72:11:36.6 |
HIP 16392 |
13.35 |
| 2026-06-03 00:00 |
03:33:10.90 |
-72:12:04.7 |
HIP 16392 |
14.06 |
| 2026-06-03 12:00 |
03:33:33.10 |
-72:12:33.3 |
HIP 16392 |
14.94 |
| 2026-06-04 00:00 |
03:33:55.28 |
-72:13:02.5 |
HIP 16392 |
15.95 |
| 2026-06-04 12:00 |
03:34:17.42 |
-72:13:32.2 |
HIP 16392 |
17.08 |
| 2026-06-05 00:00 |
03:34:39.54 |
-72:14:02.5 |
HIP 16392 |
18.30 |
| 2026-06-05 12:00 |
03:35:01.63 |
-72:14:33.4 |
HIP 16392 |
19.59 |
| 2026-06-06 00:00 |
03:35:23.68 |
-72:15:04.9 |
HIP 16392 |
20.94 |
| 2026-06-06 12:00 |
03:35:45.70 |
-72:15:37.0 |
HIP 16392 |
22.34 |
| 2026-06-07 00:00 |
03:36:07.70 |
-72:16:09.6 |
HIP 16392 |
23.79 |
| 2026-06-07 12:00 |
03:36:29.65 |
-72:16:42.8 |
HIP 16392 |
25.26 |
| 2026-06-08 00:00 |
03:36:51.58 |
-72:17:16.5 |
HIP 16392 |
26.77 |
| 2026-06-08 12:00 |
03:37:13.47 |
-72:17:50.8 |
HIP 16392 |
28.29 |
| 2026-06-09 00:00 |
03:37:35.32 |
-72:18:25.7 |
HIP 16392 |
29.84 |
| 2026-06-09 12:00 |
03:37:57.14 |
-72:19:01.2 |
HIP 17402 |
31.38 |
| 2026-06-10 00:00 |
03:38:18.92 |
-72:19:37.2 |
HIP 17402 |
29.68 |
| 2026-06-10 12:00 |
03:38:40.66 |
-72:20:13.7 |
HIP 17402 |
27.99 |
| 2026-06-11 00:00 |
03:39:02.37 |
-72:20:50.9 |
HIP 17402 |
26.30 |
| 2026-06-11 12:00 |
03:39:24.03 |
-72:21:28.6 |
HIP 17402 |
24.61 |
| 2026-06-12 00:00 |
03:39:45.66 |
-72:22:06.8 |
HIP 17402 |
22.94 |
| 2026-06-12 12:00 |
03:40:07.24 |
-72:22:45.7 |
HIP 17402 |
21.27 |
| 2026-06-13 00:00 |
03:40:28.78 |
-72:23:25.0 |
HIP 17402 |
19.62 |
| 2026-06-13 12:00 |
03:40:50.28 |
-72:24:05.0 |
HIP 17402 |
17.98 |
| 2026-06-14 00:00 |
03:41:11.74 |
-72:24:45.4 |
HIP 17402 |
16.36 |
| 2026-06-14 12:00 |
03:41:33.15 |
-72:25:26.5 |
HIP 17402 |
14.76 |
| 2026-06-15 00:00 |
03:41:54.51 |
-72:26:08.0 |
HIP 17402 |
13.21 |
| 2026-06-15 12:00 |
03:42:15.83 |
-72:26:50.2 |
HIP 17402 |
11.70 |
| 2026-06-16 00:00 |
03:42:37.10 |
-72:27:32.8 |
HIP 17402 |
10.26 |
| 2026-06-16 12:00 |
03:42:58.32 |
-72:28:16.0 |
HIP 17402 |
8.93 |
| 2026-06-17 00:00 |
03:43:19.50 |
-72:28:59.8 |
HIP 17402 |
7.75 |
| 2026-06-17 12:00 |
03:43:40.62 |
-72:29:44.1 |
HIP 17402 |
6.82 |
| 2026-06-18 00:00 |
03:44:01.69 |
-72:30:28.9 |
HIP 17402 |
6.24 |
| 2026-06-18 12:00 |
03:44:22.71 |
-72:31:14.3 |
HIP 17402 |
6.10 |
| 2026-06-19 00:00 |
03:44:43.68 |
-72:32:00.2 |
HIP 17402 |
6.45 |
| 2026-06-19 12:00 |
03:45:04.59 |
-72:32:46.6 |
HIP 17402 |
7.20 |
| 2026-06-20 00:00 |
03:45:25.45 |
-72:33:33.5 |
HIP 17402 |
8.26 |
| 2026-06-20 12:00 |
03:45:46.26 |
-72:34:21.0 |
HIP 17402 |
9.51 |
| 2026-06-21 00:00 |
03:46:07.01 |
-72:35:08.9 |
HIP 17402 |
10.89 |
| 2026-06-21 12:00 |
03:46:27.70 |
-72:35:57.4 |
HIP 17402 |
12.35 |
| 2026-06-22 00:00 |
03:46:48.33 |
-72:36:46.5 |
HIP 17402 |
13.88 |