C/2017 U2 (Fuls)
| 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) |
| 2026-02-03 00:00 |
02:19:04.15 |
-74:45:50.2 |
HIP 10874 |
12.43 |
| 2026-02-03 12:00 |
02:19:11.17 |
-74:44:24.0 |
HIP 10874 |
10.92 |
| 2026-02-04 00:00 |
02:19:18.36 |
-74:42:57.8 |
HIP 10874 |
9.41 |
| 2026-02-04 12:00 |
02:19:25.73 |
-74:41:31.8 |
HIP 10874 |
7.89 |
| 2026-02-05 00:00 |
02:19:33.26 |
-74:40:05.9 |
HIP 10874 |
6.38 |
| 2026-02-05 12:00 |
02:19:40.96 |
-74:38:40.0 |
HIP 10874 |
4.87 |
| 2026-02-06 00:00 |
02:19:48.83 |
-74:37:14.3 |
HIP 10874 |
3.37 |
| 2026-02-06 12:00 |
02:19:56.86 |
-74:35:48.7 |
HIP 10874 |
1.90 |
| 2026-02-07 00:00 |
02:20:05.06 |
-74:34:23.3 |
HIP 10874 |
0.72 |
| 2026-02-07 12:00 |
02:20:13.43 |
-74:32:58.0 |
HIP 10874 |
1.45 |
| 2026-02-08 00:00 |
02:20:21.95 |
-74:31:32.8 |
HIP 10874 |
2.89 |
| 2026-02-08 12:00 |
02:20:30.64 |
-74:30:07.8 |
HIP 10874 |
4.40 |
| 2026-02-09 00:00 |
02:20:39.49 |
-74:28:42.9 |
HIP 10874 |
5.92 |
| 2026-02-09 12:00 |
02:20:48.50 |
-74:27:18.2 |
HIP 10874 |
7.45 |
| 2026-02-10 00:00 |
02:20:57.67 |
-74:25:53.7 |
HIP 10874 |
8.99 |
| 2026-02-10 12:00 |
02:21:07.00 |
-74:24:29.3 |
HIP 10874 |
10.52 |
| 2026-02-11 00:00 |
02:21:16.48 |
-74:23:05.1 |
HIP 10874 |
12.06 |
| 2026-02-11 12:00 |
02:21:26.13 |
-74:21:41.0 |
HIP 11196 |
12.00 |
| 2026-02-12 00:00 |
02:21:35.92 |
-74:20:17.2 |
HIP 11196 |
12.02 |
| 2026-02-12 12:00 |
02:21:45.88 |
-74:18:53.5 |
HIP 11196 |
12.22 |
| 2026-02-13 00:00 |
02:21:55.98 |
-74:17:30.1 |
HIP 11196 |
12.60 |
| 2026-02-13 12:00 |
02:22:06.24 |
-74:16:06.8 |
HIP 11196 |
13.14 |
| 2026-02-14 00:00 |
02:22:16.65 |
-74:14:43.8 |
HIP 11196 |
13.83 |
| 2026-02-14 12:00 |
02:22:27.21 |
-74:13:20.9 |
HIP 10947 |
14.60 |
| 2026-02-15 00:00 |
02:22:37.92 |
-74:11:58.3 |
HIP 10947 |
13.70 |
| 2026-02-15 12:00 |
02:22:48.78 |
-74:10:35.9 |
HIP 10947 |
12.93 |
| 2026-02-16 00:00 |
02:22:59.78 |
-74:09:13.8 |
HIP 10947 |
12.33 |
| 2026-02-16 12:00 |
02:23:10.94 |
-74:07:51.8 |
HIP 10947 |
11.91 |
| 2026-02-17 00:00 |
02:23:22.24 |
-74:06:30.1 |
HIP 10947 |
11.70 |
| 2026-02-17 12:00 |
02:23:33.68 |
-74:05:08.7 |
HIP 10947 |
11.71 |
| 2026-02-18 00:00 |
02:23:45.26 |
-74:03:47.5 |
HIP 10947 |
11.94 |
| 2026-02-18 12:00 |
02:23:56.99 |
-74:02:26.5 |
HIP 10947 |
12.38 |
| 2026-02-19 00:00 |
02:24:08.86 |
-74:01:05.9 |
HIP 10947 |
13.01 |
| 2026-02-19 12:00 |
02:24:20.87 |
-73:59:45.4 |
HIP 10947 |
13.81 |
| 2026-02-20 00:00 |
02:24:33.02 |
-73:58:25.3 |
HIP 10947 |
14.74 |
| 2026-02-20 12:00 |
02:24:45.30 |
-73:57:05.4 |
HIP 10947 |
15.78 |
| 2026-02-21 00:00 |
02:24:57.73 |
-73:55:45.8 |
HIP 10947 |
16.92 |
| 2026-02-21 12:00 |
02:25:10.29 |
-73:54:26.5 |
HIP 10947 |
18.13 |
| 2026-02-22 00:00 |
02:25:22.98 |
-73:53:07.5 |
HIP 11095 |
17.81 |
| 2026-02-22 12:00 |
02:25:35.80 |
-73:51:48.8 |
HIP 11095 |
17.35 |
| 2026-02-23 00:00 |
02:25:48.76 |
-73:50:30.4 |
HIP 11095 |
17.04 |
| 2026-02-23 12:00 |
02:26:01.85 |
-73:49:12.2 |
HIP 11095 |
16.89 |
| 2026-02-24 00:00 |
02:26:15.07 |
-73:47:54.4 |
HIP 11095 |
16.89 |