| Parameter |
Value |
| Designation |
C/2018 A6 (Gibbs) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-07-14T07:12:03.481920Z |
| Orbit solution date (soln_date, UTC) |
2024-05-30T01:12:17Z |
| Obs used |
915 |
| NEO |
- |
| M1 |
9.700 |
| K1 |
7.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-12-10.0000000 |
| e |
0.80342745 |
| q (au) |
3.017827 |
| a (au) |
15.352231 |
| i (deg) |
76.954875 |
| Ω (om, deg) |
340.386138 |
| ω (w, deg) |
264.536453 |
| M (ma, deg) |
2.436451 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.874 + 3.973\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.874 |
| n |
3.973 |
| gf |
1.000 |
| gb |
-0.500 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2017-04-03 |
2018-02-13 |
-4.4374 |
+4.270 |
| 2018-02-13 |
2019-07-08 |
+5.4711 |
-3.199 |
| 2019-07-20 |
2020-06-07 |
+11.2381 |
-6.514 |
| 2020-06-07 |
2021-10-03 |
-7.5580 |
+5.191 |
| 2021-10-03 |
2023-10-19 |
-7.6929 |
+5.633 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
22:21:27.97 |
+41:45:38.8 |
HIP 110373 |
2.51 |
| 2026-07-29 12:00 |
22:21:18.63 |
+41:46:16.0 |
HIP 110373 |
1.60 |
| 2026-07-30 00:00 |
22:21:09.24 |
+41:46:52.3 |
HIP 110373 |
2.40 |
| 2026-07-30 12:00 |
22:20:59.80 |
+41:47:27.8 |
HIP 110373 |
3.99 |
| 2026-07-31 00:00 |
22:20:50.32 |
+41:48:02.5 |
HIP 110373 |
5.75 |
| 2026-07-31 12:00 |
22:20:40.80 |
+41:48:36.2 |
HIP 110373 |
7.56 |
| 2026-08-01 00:00 |
22:20:31.24 |
+41:49:09.1 |
HIP 110373 |
9.39 |
| 2026-08-01 12:00 |
22:20:21.63 |
+41:49:41.2 |
HIP 110373 |
11.24 |
| 2026-08-02 00:00 |
22:20:11.98 |
+41:50:12.4 |
HIP 110373 |
13.11 |
| 2026-08-02 12:00 |
22:20:02.30 |
+41:50:42.7 |
HIP 110373 |
14.97 |
| 2026-08-03 00:00 |
22:19:52.57 |
+41:51:12.1 |
HIP 110373 |
16.84 |
| 2026-08-03 12:00 |
22:19:42.80 |
+41:51:40.7 |
HIP 110373 |
18.72 |
| 2026-08-04 00:00 |
22:19:33.00 |
+41:52:08.4 |
HIP 110155 |
18.61 |
| 2026-08-04 12:00 |
22:19:23.15 |
+41:52:35.2 |
HIP 110155 |
17.41 |
| 2026-08-05 00:00 |
22:19:13.27 |
+41:53:01.1 |
HIP 110155 |
16.35 |
| 2026-08-05 12:00 |
22:19:03.36 |
+41:53:26.1 |
HIP 110155 |
15.47 |
| 2026-08-06 00:00 |
22:18:53.41 |
+41:53:50.2 |
HIP 110155 |
14.79 |
| 2026-08-06 12:00 |
22:18:43.42 |
+41:54:13.5 |
HIP 110155 |
14.34 |
| 2026-08-07 00:00 |
22:18:33.41 |
+41:54:35.9 |
HIP 110155 |
14.15 |
| 2026-08-07 12:00 |
22:18:23.36 |
+41:54:57.3 |
HIP 110155 |
14.23 |
| 2026-08-08 00:00 |
22:18:13.27 |
+41:55:17.9 |
HIP 110155 |
14.57 |
| 2026-08-08 12:00 |
22:18:03.16 |
+41:55:37.6 |
HIP 110155 |
15.17 |
| 2026-08-09 00:00 |
22:17:53.02 |
+41:55:56.3 |
HIP 110155 |
15.98 |
| 2026-08-09 12:00 |
22:17:42.85 |
+41:56:14.2 |
HIP 110155 |
16.99 |
| 2026-08-10 00:00 |
22:17:32.64 |
+41:56:31.1 |
HIP 110155 |
18.16 |
| 2026-08-10 12:00 |
22:17:22.42 |
+41:56:47.2 |
HIP 110155 |
19.45 |
| 2026-08-11 00:00 |
22:17:12.16 |
+41:57:02.3 |
HIP 110155 |
20.86 |
| 2026-08-11 12:00 |
22:17:01.88 |
+41:57:16.6 |
HIP 110155 |
22.36 |
| 2026-08-12 00:00 |
22:16:51.58 |
+41:57:29.9 |
HIP 110155 |
23.92 |
| 2026-08-12 12:00 |
22:16:41.25 |
+41:57:42.3 |
HIP 110155 |
25.55 |
| 2026-08-13 00:00 |
22:16:30.90 |
+41:57:53.8 |
HIP 109800 |
25.25 |
| 2026-08-13 12:00 |
22:16:20.53 |
+41:58:04.4 |
HIP 109800 |
23.37 |
| 2026-08-14 00:00 |
22:16:10.13 |
+41:58:14.1 |
HIP 109800 |
21.51 |
| 2026-08-14 12:00 |
22:15:59.72 |
+41:58:22.8 |
HIP 109800 |
19.66 |
| 2026-08-15 00:00 |
22:15:49.29 |
+41:58:30.7 |
HIP 109800 |
17.84 |
| 2026-08-15 12:00 |
22:15:38.84 |
+41:58:37.6 |
HIP 109800 |
16.04 |
| 2026-08-16 00:00 |
22:15:28.38 |
+41:58:43.6 |
HIP 109800 |
14.30 |
| 2026-08-16 12:00 |
22:15:17.89 |
+41:58:48.8 |
HIP 109800 |
12.61 |
| 2026-08-17 00:00 |
22:15:07.40 |
+41:58:53.0 |
HIP 109800 |
11.03 |
| 2026-08-17 12:00 |
22:14:56.89 |
+41:58:56.3 |
HIP 109800 |
9.58 |
| 2026-08-18 00:00 |
22:14:46.36 |
+41:58:58.7 |
HIP 109800 |
8.36 |
| 2026-08-18 12:00 |
22:14:35.83 |
+41:59:00.1 |
HIP 109800 |
7.47 |
| 2026-08-19 00:00 |
22:14:25.28 |
+41:59:00.7 |
HIP 109800 |
7.05 |