| Parameter |
Value |
| Designation |
390P/Gibbs |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2020-03-23T23:00:23.420160Z |
| Orbit solution date (soln_date, UTC) |
2024-03-04T23:13:05Z |
| Obs used |
339 |
| NEO |
- |
| M1 |
12.300 |
| K1 |
10.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2019-10-21T05:56:28.665600Z |
| Discovery magnitude (MPC) |
18.45 c |
| Discovery observatory (MPC) |
T05 · ATLAS-HKO, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2016-03-25.0000000 |
| e |
0.70581897 |
| q (au) |
1.709156 |
| a (au) |
5.809877 |
| i (deg) |
18.522010 |
| Ω (om, deg) |
152.717702 |
| ω (w, deg) |
231.735413 |
| M (ma, deg) |
257.247066 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.035 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.035 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.694 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2019-08-08 |
2020-01-21 |
+11.1256 |
-3.908 |
| 2020-09-01 |
2021-03-06 |
+1.2842 |
-0.774 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
13:29:44.74 |
+06:26:42.2 |
HIP 65736 |
24.41 |
| 2026-03-26 12:00 |
13:29:35.23 |
+06:28:01.8 |
HIP 65736 |
21.75 |
| 2026-03-27 00:00 |
13:29:25.69 |
+06:29:21.2 |
HIP 65736 |
19.10 |
| 2026-03-27 12:00 |
13:29:16.11 |
+06:30:40.3 |
HIP 65736 |
16.46 |
| 2026-03-28 00:00 |
13:29:06.49 |
+06:31:59.1 |
HIP 65736 |
13.85 |
| 2026-03-28 12:00 |
13:28:56.84 |
+06:33:17.7 |
HIP 65736 |
11.29 |
| 2026-03-29 00:00 |
13:28:47.15 |
+06:34:36.1 |
HIP 65736 |
8.84 |
| 2026-03-29 12:00 |
13:28:37.43 |
+06:35:54.1 |
HIP 65736 |
6.62 |
| 2026-03-30 00:00 |
13:28:27.68 |
+06:37:11.9 |
HIP 65736 |
4.95 |
| 2026-03-30 12:00 |
13:28:17.90 |
+06:38:29.3 |
HIP 65736 |
4.52 |
| 2026-03-31 00:00 |
13:28:08.09 |
+06:39:46.5 |
HIP 65736 |
5.61 |
| 2026-03-31 12:00 |
13:27:58.25 |
+06:41:03.4 |
HIP 65736 |
7.61 |
| 2026-04-01 00:00 |
13:27:48.38 |
+06:42:19.9 |
HIP 65736 |
9.98 |
| 2026-04-01 12:00 |
13:27:38.49 |
+06:43:36.1 |
HIP 65736 |
12.52 |
| 2026-04-02 00:00 |
13:27:28.57 |
+06:44:52.0 |
HIP 65736 |
15.15 |
| 2026-04-02 12:00 |
13:27:18.63 |
+06:46:07.5 |
HIP 65736 |
17.82 |
| 2026-04-03 00:00 |
13:27:08.67 |
+06:47:22.7 |
HIP 65736 |
20.52 |
| 2026-04-03 12:00 |
13:26:58.68 |
+06:48:37.5 |
HIP 65516 |
21.88 |
| 2026-04-04 00:00 |
13:26:48.68 |
+06:49:52.0 |
HIP 65516 |
20.77 |
| 2026-04-04 12:00 |
13:26:38.65 |
+06:51:06.1 |
HIP 65516 |
19.97 |
| 2026-04-05 00:00 |
13:26:28.61 |
+06:52:19.8 |
HIP 65516 |
19.53 |
| 2026-04-05 12:00 |
13:26:18.55 |
+06:53:33.1 |
HIP 65516 |
19.48 |
| 2026-04-06 00:00 |
13:26:08.47 |
+06:54:46.1 |
HIP 65516 |
19.81 |
| 2026-04-06 12:00 |
13:25:58.38 |
+06:55:58.6 |
HIP 65516 |
20.51 |
| 2026-04-07 00:00 |
13:25:48.27 |
+06:57:10.7 |
HIP 65516 |
21.54 |
| 2026-04-07 12:00 |
13:25:38.15 |
+06:58:22.5 |
HIP 65516 |
22.86 |
| 2026-04-08 00:00 |
13:25:28.02 |
+06:59:33.8 |
HIP 65516 |
24.42 |
| 2026-04-08 12:00 |
13:25:17.88 |
+07:00:44.6 |
HIP 65516 |
26.18 |
| 2026-04-09 00:00 |
13:25:07.73 |
+07:01:55.0 |
HIP 65516 |
28.09 |
| 2026-04-09 12:00 |
13:24:57.57 |
+07:03:05.0 |
HIP 65516 |
30.14 |
| 2026-04-10 00:00 |
13:24:47.41 |
+07:04:14.6 |
HIP 65558 |
31.54 |
| 2026-04-10 12:00 |
13:24:37.24 |
+07:05:23.6 |
HIP 65558 |
32.88 |
| 2026-04-11 00:00 |
13:24:27.06 |
+07:06:32.2 |
HIP 65558 |
34.40 |
| 2026-04-11 12:00 |
13:24:16.88 |
+07:07:40.3 |
HIP 65558 |
36.06 |
| 2026-04-12 00:00 |
13:24:06.70 |
+07:08:48.0 |
HIP 65558 |
37.86 |
| 2026-04-12 12:00 |
13:23:56.52 |
+07:09:55.1 |
HIP 65262 |
36.60 |
| 2026-04-13 00:00 |
13:23:46.34 |
+07:11:01.8 |
HIP 65262 |
34.23 |
| 2026-04-13 12:00 |
13:23:36.16 |
+07:12:08.0 |
HIP 65262 |
31.94 |
| 2026-04-14 00:00 |
13:23:25.98 |
+07:13:13.6 |
HIP 65262 |
29.74 |
| 2026-04-14 12:00 |
13:23:15.81 |
+07:14:18.7 |
HIP 65262 |
27.64 |
| 2026-04-15 00:00 |
13:23:05.64 |
+07:15:23.3 |
HIP 65262 |
25.67 |
| 2026-04-15 12:00 |
13:22:55.47 |
+07:16:27.4 |
HIP 65262 |
23.87 |
| 2026-04-16 00:00 |
13:22:45.32 |
+07:17:31.0 |
HIP 65262 |
22.27 |