| Parameter |
Value |
| Designation |
C/2018 R4 (Fuls) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-03-03T15:59:10.642560Z |
| Orbit solution date (soln_date, UTC) |
2022-06-20T23:12:32Z |
| Obs used |
114 |
| NEO |
- |
| M1 |
16.300 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2018-09-09T07:28:08.544000Z |
| Discovery magnitude (MPC) |
19.10 G |
| Discovery observatory (MPC) |
703 · University of Arizona Catalina Sky Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-09-02.0000000 |
| e |
0.99435878 |
| q (au) |
1.709214 |
| a (au) |
302.986704 |
| i (deg) |
11.682034 |
| Ω (om, deg) |
298.460925 |
| ω (w, deg) |
345.148323 |
| M (ma, deg) |
0.034075 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.140 + 3.865\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.140 |
| n |
3.865 |
| gf |
1.000 |
| gb |
-0.685 |
| k |
0.800 |
| 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) |
| 2026-07-29 00:00 |
04:46:53.66 |
+30:43:33.5 |
HIP 22117 |
21.85 |
| 2026-07-29 12:00 |
04:46:57.79 |
+30:43:48.4 |
HIP 22117 |
22.39 |
| 2026-07-30 00:00 |
04:47:01.89 |
+30:44:03.3 |
HIP 22117 |
22.95 |
| 2026-07-30 12:00 |
04:47:05.94 |
+30:44:18.2 |
HIP 22117 |
23.52 |
| 2026-07-31 00:00 |
04:47:09.95 |
+30:44:33.0 |
HIP 22117 |
24.10 |
| 2026-07-31 12:00 |
04:47:13.92 |
+30:44:47.9 |
HIP 22117 |
24.70 |
| 2026-08-01 00:00 |
04:47:17.85 |
+30:45:02.8 |
HIP 22117 |
25.30 |
| 2026-08-01 12:00 |
04:47:21.74 |
+30:45:17.6 |
HIP 22375 |
24.68 |
| 2026-08-02 00:00 |
04:47:25.60 |
+30:45:32.4 |
HIP 22375 |
23.84 |
| 2026-08-02 12:00 |
04:47:29.41 |
+30:45:47.2 |
HIP 22375 |
23.02 |
| 2026-08-03 00:00 |
04:47:33.18 |
+30:46:02.0 |
HIP 22375 |
22.20 |
| 2026-08-03 12:00 |
04:47:36.90 |
+30:46:16.8 |
HIP 22375 |
21.39 |
| 2026-08-04 00:00 |
04:47:40.59 |
+30:46:31.6 |
HIP 22375 |
20.60 |
| 2026-08-04 12:00 |
04:47:44.24 |
+30:46:46.3 |
HIP 22375 |
19.81 |
| 2026-08-05 00:00 |
04:47:47.84 |
+30:47:01.1 |
HIP 22375 |
19.04 |
| 2026-08-05 12:00 |
04:47:51.40 |
+30:47:15.8 |
HIP 22375 |
18.28 |
| 2026-08-06 00:00 |
04:47:54.92 |
+30:47:30.5 |
HIP 22375 |
17.52 |
| 2026-08-06 12:00 |
04:47:58.39 |
+30:47:45.1 |
HIP 22375 |
16.78 |
| 2026-08-07 00:00 |
04:48:01.83 |
+30:47:59.8 |
HIP 22375 |
16.05 |
| 2026-08-07 12:00 |
04:48:05.21 |
+30:48:14.4 |
HIP 22375 |
15.34 |
| 2026-08-08 00:00 |
04:48:08.56 |
+30:48:29.0 |
HIP 22375 |
14.63 |
| 2026-08-08 12:00 |
04:48:11.86 |
+30:48:43.6 |
HIP 22375 |
13.94 |
| 2026-08-09 00:00 |
04:48:15.12 |
+30:48:58.1 |
HIP 22375 |
13.26 |
| 2026-08-09 12:00 |
04:48:18.33 |
+30:49:12.7 |
HIP 22375 |
12.59 |
| 2026-08-10 00:00 |
04:48:21.50 |
+30:49:27.2 |
HIP 22375 |
11.94 |
| 2026-08-10 12:00 |
04:48:24.62 |
+30:49:41.6 |
HIP 22375 |
11.31 |
| 2026-08-11 00:00 |
04:48:27.70 |
+30:49:56.1 |
HIP 22375 |
10.69 |
| 2026-08-11 12:00 |
04:48:30.73 |
+30:50:10.5 |
HIP 22375 |
10.09 |
| 2026-08-12 00:00 |
04:48:33.71 |
+30:50:24.9 |
HIP 22375 |
9.51 |
| 2026-08-12 12:00 |
04:48:36.65 |
+30:50:39.2 |
HIP 22375 |
8.95 |
| 2026-08-13 00:00 |
04:48:39.55 |
+30:50:53.6 |
HIP 22375 |
8.41 |
| 2026-08-13 12:00 |
04:48:42.39 |
+30:51:07.9 |
HIP 22375 |
7.89 |
| 2026-08-14 00:00 |
04:48:45.19 |
+30:51:22.1 |
HIP 22375 |
7.41 |
| 2026-08-14 12:00 |
04:48:47.95 |
+30:51:36.3 |
HIP 22375 |
6.95 |
| 2026-08-15 00:00 |
04:48:50.65 |
+30:51:50.5 |
HIP 22375 |
6.53 |
| 2026-08-15 12:00 |
04:48:53.31 |
+30:52:04.7 |
HIP 22375 |
6.14 |
| 2026-08-16 00:00 |
04:48:55.92 |
+30:52:18.8 |
HIP 22375 |
5.80 |
| 2026-08-16 12:00 |
04:48:58.48 |
+30:52:32.9 |
HIP 22375 |
5.50 |
| 2026-08-17 00:00 |
04:49:01.00 |
+30:52:46.9 |
HIP 22375 |
5.26 |
| 2026-08-17 12:00 |
04:49:03.47 |
+30:53:00.9 |
HIP 22375 |
5.07 |
| 2026-08-18 00:00 |
04:49:05.89 |
+30:53:14.9 |
HIP 22375 |
4.95 |
| 2026-08-18 12:00 |
04:49:08.26 |
+30:53:28.8 |
HIP 22375 |
4.88 |
| 2026-08-19 00:00 |
04:49:10.58 |
+30:53:42.7 |
HIP 22375 |
4.87 |