| Parameter |
Value |
| Designation |
428P/Gibbs |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2014-11-14T13:43:38.052480Z |
| Orbit solution date (soln_date, UTC) |
2023-05-03T22:44:57Z |
| Obs used |
130 |
| NEO |
- |
| M1 |
11.700 |
| K1 |
22.750 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2021-08-16T03:08:49.632000Z |
| Discovery magnitude (MPC) |
20.00 T |
| Discovery observatory (MPC) |
Z84 · Calar Alto-Schmidt |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-07-29.0000000 |
| e |
0.51895674 |
| q (au) |
1.675591 |
| a (au) |
3.483245 |
| i (deg) |
8.514132 |
| Ω (om, deg) |
299.322409 |
| ω (w, deg) |
36.937480 |
| M (ma, deg) |
149.704035 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.349 + 5.458\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.349 |
| n |
5.458 |
| gf |
0.999 |
| gb |
-0.874 |
| k |
0.999 |
| δ90 |
9.999 |
| 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) |
| 2026-09-20 00:00 |
13:19:45.79 |
-15:48:49.8 |
HIP 64993 |
16.27 |
| 2026-09-20 12:00 |
13:20:19.48 |
-15:51:42.8 |
HIP 64993 |
23.10 |
| 2026-09-21 00:00 |
13:20:53.25 |
-15:54:36.3 |
HIP 64993 |
30.86 |
| 2026-09-21 12:00 |
13:21:27.12 |
-15:57:30.2 |
HIP 65310 |
24.06 |
| 2026-09-22 00:00 |
13:22:01.07 |
-16:00:24.6 |
HIP 65310 |
16.52 |
| 2026-09-22 12:00 |
13:22:35.11 |
-16:03:19.5 |
HIP 65310 |
10.81 |
| 2026-09-23 00:00 |
13:23:09.24 |
-16:06:14.8 |
HIP 65310 |
10.58 |
| 2026-09-23 12:00 |
13:23:43.45 |
-16:09:10.7 |
HIP 65310 |
16.10 |
| 2026-09-24 00:00 |
13:24:17.75 |
-16:12:06.9 |
HIP 65310 |
23.65 |
| 2026-09-24 12:00 |
13:24:52.14 |
-16:15:03.6 |
HIP 65575 |
27.48 |
| 2026-09-25 00:00 |
13:25:26.61 |
-16:18:00.8 |
HIP 65575 |
21.29 |
| 2026-09-25 12:00 |
13:26:01.17 |
-16:20:58.3 |
HIP 65575 |
17.48 |
| 2026-09-26 00:00 |
13:26:35.81 |
-16:23:56.4 |
HIP 65552 |
17.09 |
| 2026-09-26 12:00 |
13:27:10.54 |
-16:26:54.8 |
HIP 65552 |
18.37 |
| 2026-09-27 00:00 |
13:27:45.35 |
-16:29:53.6 |
HIP 65552 |
23.23 |
| 2026-09-27 12:00 |
13:28:20.25 |
-16:32:52.9 |
HIP 65552 |
30.00 |
| 2026-09-28 00:00 |
13:28:55.23 |
-16:35:52.6 |
HIP 65912 |
33.99 |
| 2026-09-28 12:00 |
13:29:30.29 |
-16:38:52.7 |
HIP 65939 |
28.98 |
| 2026-09-29 00:00 |
13:30:05.44 |
-16:41:53.2 |
HIP 65939 |
25.30 |
| 2026-09-29 12:00 |
13:30:40.67 |
-16:44:54.1 |
HIP 65939 |
24.50 |
| 2026-09-30 00:00 |
13:31:15.99 |
-16:47:55.3 |
HIP 65939 |
26.87 |
| 2026-09-30 12:00 |
13:31:51.39 |
-16:50:57.0 |
HIP 65939 |
31.72 |
| 2026-10-01 00:00 |
13:32:26.87 |
-16:53:59.0 |
HIP 65939 |
38.12 |
| 2026-10-01 12:00 |
13:33:02.44 |
-16:57:01.5 |
HIP 66231 |
31.28 |
| 2026-10-02 00:00 |
13:33:38.09 |
-17:00:04.3 |
HIP 66231 |
23.93 |
| 2026-10-02 12:00 |
13:34:13.82 |
-17:03:07.4 |
HIP 66231 |
18.19 |
| 2026-10-03 00:00 |
13:34:49.64 |
-17:06:10.9 |
HIP 66319 |
14.60 |
| 2026-10-03 12:00 |
13:35:25.53 |
-17:09:14.8 |
HIP 66319 |
13.87 |
| 2026-10-04 00:00 |
13:36:01.51 |
-17:12:19.0 |
HIP 66319 |
18.39 |
| 2026-10-04 12:00 |
13:36:37.57 |
-17:15:23.6 |
HIP 66319 |
25.52 |
| 2026-10-05 00:00 |
13:37:13.71 |
-17:18:28.5 |
HIP 66319 |
33.66 |
| 2026-10-05 12:00 |
13:37:49.93 |
-17:21:33.7 |
HIP 66717 |
38.81 |
| 2026-10-06 00:00 |
13:38:26.24 |
-17:24:39.3 |
HIP 66717 |
30.40 |
| 2026-10-06 12:00 |
13:39:02.62 |
-17:27:45.2 |
HIP 66717 |
22.60 |
| 2026-10-07 00:00 |
13:39:39.08 |
-17:30:51.4 |
HIP 66717 |
16.35 |
| 2026-10-07 12:00 |
13:40:15.63 |
-17:33:57.9 |
HIP 66717 |
13.94 |
| 2026-10-08 00:00 |
13:40:52.25 |
-17:37:04.7 |
HIP 66749 |
10.49 |
| 2026-10-08 12:00 |
13:41:28.95 |
-17:40:11.8 |
HIP 66749 |
11.70 |
| 2026-10-09 00:00 |
13:42:05.73 |
-17:43:19.2 |
HIP 66749 |
18.35 |
| 2026-10-09 12:00 |
13:42:42.58 |
-17:46:26.9 |
HIP 66749 |
26.65 |
| 2026-10-10 00:00 |
13:43:19.52 |
-17:49:34.9 |
HIP 67060 |
18.33 |
| 2026-10-10 12:00 |
13:43:56.53 |
-17:52:43.1 |
HIP 67060 |
8.99 |
| 2026-10-11 00:00 |
13:44:33.62 |
-17:55:51.6 |
HIP 67060 |
0.66 |