| Parameter |
Value |
| Designation |
C/2021 Q4 (Fuls) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-06-10T10:47:21.906240Z |
| Orbit solution date (soln_date, UTC) |
2025-10-03T14:42:16Z |
| Obs used |
558 |
| NEO |
- |
| M1 |
6.800 |
| K1 |
9.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-08-26T07:09:57.139200Z |
| Discovery magnitude (MPC) |
20.07 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-04-14.0000000 |
| e |
1.00316029 |
| q (au) |
7.564703 |
| a (au) |
-2393.669779 |
| i (deg) |
71.474447 |
| Ω (om, deg) |
183.332460 |
| ω (w, deg) |
146.998903 |
| M (ma, deg) |
-0.000483 |
Magnitude
Scatter + Global Linear
$$
M_a = (0.695 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
0.695 |
| n |
6.000 |
| gf |
0.998 |
| 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 |
01:12:19.06 |
-14:44:23.3 |
HIP 5607 |
12.62 |
| 2026-03-26 12:00 |
01:12:32.46 |
-14:43:59.2 |
HIP 5607 |
14.14 |
| 2026-03-27 00:00 |
01:12:45.87 |
-14:43:35.5 |
HIP 5607 |
16.18 |
| 2026-03-27 12:00 |
01:12:59.30 |
-14:43:12.2 |
HIP 5756 |
15.48 |
| 2026-03-28 00:00 |
01:13:12.74 |
-14:42:49.2 |
HIP 5756 |
13.15 |
| 2026-03-28 12:00 |
01:13:26.20 |
-14:42:26.6 |
HIP 5756 |
11.29 |
| 2026-03-29 00:00 |
01:13:39.66 |
-14:42:04.4 |
HIP 5756 |
10.16 |
| 2026-03-29 12:00 |
01:13:53.14 |
-14:41:42.6 |
HIP 5756 |
10.02 |
| 2026-03-30 00:00 |
01:14:06.63 |
-14:41:21.2 |
HIP 5756 |
10.91 |
| 2026-03-30 12:00 |
01:14:20.13 |
-14:41:00.2 |
HIP 5756 |
12.60 |
| 2026-03-31 00:00 |
01:14:33.64 |
-14:40:39.6 |
HIP 5756 |
14.84 |
| 2026-03-31 12:00 |
01:14:47.16 |
-14:40:19.4 |
HIP 5756 |
17.41 |
| 2026-04-01 00:00 |
01:15:00.70 |
-14:39:59.6 |
HIP 5756 |
20.18 |
| 2026-04-01 12:00 |
01:15:14.24 |
-14:39:40.3 |
HIP 5756 |
23.09 |
| 2026-04-02 00:00 |
01:15:27.78 |
-14:39:21.3 |
HIP 5756 |
26.09 |
| 2026-04-02 12:00 |
01:15:41.34 |
-14:39:02.8 |
HIP 5808 |
28.27 |
| 2026-04-03 00:00 |
01:15:54.90 |
-14:38:44.7 |
HIP 6028 |
26.38 |
| 2026-04-03 12:00 |
01:16:08.48 |
-14:38:27.0 |
HIP 6028 |
23.51 |
| 2026-04-04 00:00 |
01:16:22.05 |
-14:38:09.8 |
HIP 6028 |
20.77 |
| 2026-04-04 12:00 |
01:16:35.64 |
-14:37:53.0 |
HIP 6028 |
18.21 |
| 2026-04-05 00:00 |
01:16:49.23 |
-14:37:36.6 |
HIP 6028 |
15.95 |
| 2026-04-05 12:00 |
01:17:02.82 |
-14:37:20.7 |
HIP 6028 |
14.10 |
| 2026-04-06 00:00 |
01:17:16.42 |
-14:37:05.3 |
HIP 6028 |
12.85 |
| 2026-04-06 12:00 |
01:17:30.03 |
-14:36:50.2 |
HIP 6028 |
12.39 |
| 2026-04-07 00:00 |
01:17:43.64 |
-14:36:35.7 |
HIP 6028 |
12.80 |
| 2026-04-07 12:00 |
01:17:57.25 |
-14:36:21.6 |
HIP 6028 |
14.01 |
| 2026-04-08 00:00 |
01:18:10.86 |
-14:36:08.0 |
HIP 6028 |
15.84 |
| 2026-04-08 12:00 |
01:18:24.48 |
-14:35:54.8 |
HIP 6164 |
17.57 |
| 2026-04-09 00:00 |
01:18:38.10 |
-14:35:42.1 |
HIP 6164 |
16.21 |
| 2026-04-09 12:00 |
01:18:51.72 |
-14:35:29.9 |
HIP 6164 |
15.44 |
| 2026-04-10 00:00 |
01:19:05.34 |
-14:35:18.2 |
HIP 6164 |
15.35 |
| 2026-04-10 12:00 |
01:19:18.96 |
-14:35:06.9 |
HIP 6164 |
15.95 |
| 2026-04-11 00:00 |
01:19:32.58 |
-14:34:56.1 |
HIP 6164 |
17.16 |
| 2026-04-11 12:00 |
01:19:46.20 |
-14:34:45.9 |
HIP 6164 |
18.88 |
| 2026-04-12 00:00 |
01:19:59.82 |
-14:34:36.1 |
HIP 6228 |
20.37 |
| 2026-04-12 12:00 |
01:20:13.44 |
-14:34:26.9 |
HIP 6228 |
21.16 |
| 2026-04-13 00:00 |
01:20:27.06 |
-14:34:18.1 |
HIP 6228 |
22.41 |
| 2026-04-13 12:00 |
01:20:40.67 |
-14:34:09.8 |
HIP 6228 |
24.04 |
| 2026-04-14 00:00 |
01:20:54.28 |
-14:34:02.1 |
HIP 6228 |
25.98 |
| 2026-04-14 12:00 |
01:21:07.89 |
-14:33:54.9 |
HIP 6228 |
28.17 |
| 2026-04-15 00:00 |
01:21:21.49 |
-14:33:48.2 |
HIP 6228 |
30.55 |
| 2026-04-15 12:00 |
01:21:35.09 |
-14:33:42.0 |
HIP 6228 |
33.07 |
| 2026-04-16 00:00 |
01:21:48.68 |
-14:33:36.4 |
HIP 6497 |
31.68 |