| 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 |
-0.502 |
| 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) |
| 2026-03-26 00:00 |
22:23:40.67 |
+35:25:29.0 |
HIP 110603 |
9.53 |
| 2026-03-26 12:00 |
22:23:48.06 |
+35:26:56.4 |
HIP 110603 |
8.07 |
| 2026-03-27 00:00 |
22:23:55.40 |
+35:28:24.2 |
HIP 110603 |
6.95 |
| 2026-03-27 12:00 |
22:24:02.72 |
+35:29:52.5 |
HIP 110603 |
6.35 |
| 2026-03-28 00:00 |
22:24:09.99 |
+35:31:21.2 |
HIP 110603 |
6.43 |
| 2026-03-28 12:00 |
22:24:17.22 |
+35:32:50.3 |
HIP 110603 |
7.15 |
| 2026-03-29 00:00 |
22:24:24.42 |
+35:34:19.9 |
HIP 110603 |
8.36 |
| 2026-03-29 12:00 |
22:24:31.58 |
+35:35:49.8 |
HIP 110603 |
9.88 |
| 2026-03-30 00:00 |
22:24:38.70 |
+35:37:20.2 |
HIP 110603 |
11.58 |
| 2026-03-30 12:00 |
22:24:45.78 |
+35:38:51.0 |
HIP 110603 |
13.39 |
| 2026-03-31 00:00 |
22:24:52.81 |
+35:40:22.2 |
HIP 110603 |
15.28 |
| 2026-03-31 12:00 |
22:24:59.81 |
+35:41:53.8 |
HIP 110754 |
15.60 |
| 2026-04-01 00:00 |
22:25:06.77 |
+35:43:25.8 |
HIP 110754 |
14.31 |
| 2026-04-01 12:00 |
22:25:13.69 |
+35:44:58.3 |
HIP 110754 |
13.24 |
| 2026-04-02 00:00 |
22:25:20.56 |
+35:46:31.1 |
HIP 110754 |
12.45 |
| 2026-04-02 12:00 |
22:25:27.39 |
+35:48:04.3 |
HIP 110754 |
11.98 |
| 2026-04-03 00:00 |
22:25:34.18 |
+35:49:37.8 |
HIP 110754 |
11.87 |
| 2026-04-03 12:00 |
22:25:40.93 |
+35:51:11.8 |
HIP 110754 |
12.13 |
| 2026-04-04 00:00 |
22:25:47.63 |
+35:52:46.1 |
HIP 110754 |
12.75 |
| 2026-04-04 12:00 |
22:25:54.29 |
+35:54:20.8 |
HIP 110754 |
13.66 |
| 2026-04-05 00:00 |
22:26:00.90 |
+35:55:55.9 |
HIP 110754 |
14.82 |
| 2026-04-05 12:00 |
22:26:07.47 |
+35:57:31.4 |
HIP 110754 |
16.17 |
| 2026-04-06 00:00 |
22:26:14.00 |
+35:59:07.2 |
HIP 110754 |
17.67 |
| 2026-04-06 12:00 |
22:26:20.48 |
+36:00:43.4 |
HIP 110754 |
19.28 |
| 2026-04-07 00:00 |
22:26:26.91 |
+36:02:19.9 |
HIP 110754 |
20.98 |
| 2026-04-07 12:00 |
22:26:33.30 |
+36:03:56.8 |
HIP 110754 |
22.74 |
| 2026-04-08 00:00 |
22:26:39.64 |
+36:05:34.0 |
HIP 110754 |
24.56 |
| 2026-04-08 12:00 |
22:26:45.93 |
+36:07:11.5 |
HIP 110754 |
26.41 |
| 2026-04-09 00:00 |
22:26:52.17 |
+36:08:49.4 |
HIP 110754 |
28.30 |
| 2026-04-09 12:00 |
22:26:58.37 |
+36:10:27.7 |
HIP 110754 |
30.21 |
| 2026-04-10 00:00 |
22:27:04.51 |
+36:12:06.2 |
HIP 110754 |
32.14 |
| 2026-04-10 12:00 |
22:27:10.61 |
+36:13:45.1 |
HIP 110788 |
32.89 |
| 2026-04-11 00:00 |
22:27:16.66 |
+36:15:24.3 |
HIP 110788 |
31.50 |
| 2026-04-11 12:00 |
22:27:22.66 |
+36:17:03.8 |
HIP 110788 |
30.18 |
| 2026-04-12 00:00 |
22:27:28.60 |
+36:18:43.7 |
HIP 110788 |
28.93 |
| 2026-04-12 12:00 |
22:27:34.50 |
+36:20:23.8 |
HIP 110788 |
27.77 |
| 2026-04-13 00:00 |
22:27:40.34 |
+36:22:04.3 |
HIP 110788 |
26.70 |
| 2026-04-13 12:00 |
22:27:46.14 |
+36:23:45.0 |
HIP 110788 |
25.74 |
| 2026-04-14 00:00 |
22:27:51.88 |
+36:25:26.0 |
HIP 110788 |
24.91 |
| 2026-04-14 12:00 |
22:27:57.56 |
+36:27:07.4 |
HIP 110788 |
24.21 |
| 2026-04-15 00:00 |
22:28:03.20 |
+36:28:49.0 |
HIP 110788 |
23.65 |
| 2026-04-15 12:00 |
22:28:08.78 |
+36:30:30.8 |
HIP 110788 |
23.24 |
| 2026-04-16 00:00 |
22:28:14.30 |
+36:32:13.0 |
HIP 110788 |
23.00 |