| Parameter |
Value |
| Designation |
C/2020 H5 (Robinson) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-12-11T22:51:25.208640Z |
| Orbit solution date (soln_date, UTC) |
2025-05-08T09:42:16Z |
| Obs used |
292 |
| NEO |
- |
| M1 |
6.700 |
| K1 |
8.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-04-22T07:56:03.321600Z |
| Discovery magnitude (MPC) |
19.18 c |
| Discovery observatory (MPC) |
T05 · ATLAS-HKO, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-11-15.0000000 |
| e |
0.99727266 |
| q (au) |
9.345056 |
| a (au) |
3426.435895 |
| i (deg) |
70.232252 |
| Ω (om, deg) |
210.630689 |
| ω (w, deg) |
326.402295 |
| M (ma, deg) |
0.001661 |
Magnitude
Scatter + Global Linear
$$
M_a = (-1.226 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-1.226 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.501 |
| 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 |
| 2015-12-14 |
2020-11-22 |
+11.5399 |
-11.488 |
| 2020-12-18 |
2023-05-08 |
+6.3411 |
-6.559 |
| 2023-05-08 |
2025-05-02 |
-2.1501 |
+2.768 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
15:28:33.04 |
+20:19:03.4 |
HIP 75660 |
17.44 |
| 2026-06-01 12:00 |
15:28:26.34 |
+20:19:33.8 |
HIP 75660 |
15.84 |
| 2026-06-02 00:00 |
15:28:19.67 |
+20:20:03.5 |
HIP 75660 |
14.26 |
| 2026-06-02 12:00 |
15:28:13.02 |
+20:20:32.4 |
HIP 75660 |
12.70 |
| 2026-06-03 00:00 |
15:28:06.40 |
+20:21:00.6 |
HIP 75660 |
11.18 |
| 2026-06-03 12:00 |
15:27:59.81 |
+20:21:28.0 |
HIP 75660 |
9.71 |
| 2026-06-04 00:00 |
15:27:53.24 |
+20:21:54.7 |
HIP 75660 |
8.30 |
| 2026-06-04 12:00 |
15:27:46.70 |
+20:22:20.6 |
HIP 75660 |
6.98 |
| 2026-06-05 00:00 |
15:27:40.20 |
+20:22:45.8 |
HIP 75660 |
5.83 |
| 2026-06-05 12:00 |
15:27:33.72 |
+20:23:10.2 |
HIP 75660 |
4.93 |
| 2026-06-06 00:00 |
15:27:27.27 |
+20:23:33.8 |
HIP 75660 |
4.43 |
| 2026-06-06 12:00 |
15:27:20.85 |
+20:23:56.7 |
HIP 75660 |
4.46 |
| 2026-06-07 00:00 |
15:27:14.47 |
+20:24:18.9 |
HIP 75660 |
5.01 |
| 2026-06-07 12:00 |
15:27:08.11 |
+20:24:40.3 |
HIP 75660 |
5.91 |
| 2026-06-08 00:00 |
15:27:01.79 |
+20:25:00.9 |
HIP 75660 |
7.04 |
| 2026-06-08 12:00 |
15:26:55.50 |
+20:25:20.8 |
HIP 75660 |
8.29 |
| 2026-06-09 00:00 |
15:26:49.25 |
+20:25:40.0 |
HIP 75660 |
9.61 |
| 2026-06-09 12:00 |
15:26:43.03 |
+20:25:58.4 |
HIP 75660 |
10.96 |
| 2026-06-10 00:00 |
15:26:36.85 |
+20:26:16.0 |
HIP 75660 |
12.35 |
| 2026-06-10 12:00 |
15:26:30.70 |
+20:26:33.0 |
HIP 75660 |
13.74 |
| 2026-06-11 00:00 |
15:26:24.59 |
+20:26:49.2 |
HIP 75660 |
15.14 |
| 2026-06-11 12:00 |
15:26:18.52 |
+20:27:04.6 |
HIP 75660 |
16.55 |
| 2026-06-12 00:00 |
15:26:12.48 |
+20:27:19.3 |
HIP 75660 |
17.95 |
| 2026-06-12 12:00 |
15:26:06.49 |
+20:27:33.3 |
HIP 75660 |
19.34 |
| 2026-06-13 00:00 |
15:26:00.53 |
+20:27:46.5 |
HIP 75660 |
20.74 |
| 2026-06-13 12:00 |
15:25:54.61 |
+20:27:59.0 |
HIP 75660 |
22.12 |
| 2026-06-14 00:00 |
15:25:48.73 |
+20:28:10.8 |
HIP 75660 |
23.50 |
| 2026-06-14 12:00 |
15:25:42.90 |
+20:28:21.8 |
HIP 75660 |
24.87 |
| 2026-06-15 00:00 |
15:25:37.10 |
+20:28:32.2 |
HIP 75660 |
26.23 |
| 2026-06-15 12:00 |
15:25:31.35 |
+20:28:41.7 |
HIP 75660 |
27.58 |
| 2026-06-16 00:00 |
15:25:25.64 |
+20:28:50.6 |
HIP 75660 |
28.92 |
| 2026-06-16 12:00 |
15:25:19.98 |
+20:28:58.8 |
HIP 75660 |
30.25 |
| 2026-06-17 00:00 |
15:25:14.36 |
+20:29:06.2 |
HIP 75660 |
31.57 |
| 2026-06-17 12:00 |
15:25:08.78 |
+20:29:13.0 |
HIP 75660 |
32.88 |
| 2026-06-18 00:00 |
15:25:03.25 |
+20:29:19.0 |
HIP 75660 |
34.17 |
| 2026-06-18 12:00 |
15:24:57.77 |
+20:29:24.3 |
HIP 75249 |
33.85 |
| 2026-06-19 00:00 |
15:24:52.33 |
+20:29:28.9 |
HIP 75249 |
32.60 |
| 2026-06-19 12:00 |
15:24:46.94 |
+20:29:32.8 |
HIP 75249 |
31.37 |
| 2026-06-20 00:00 |
15:24:41.59 |
+20:29:36.1 |
HIP 75249 |
30.15 |
| 2026-06-20 12:00 |
15:24:36.29 |
+20:29:38.6 |
HIP 75249 |
28.94 |
| 2026-06-21 00:00 |
15:24:31.05 |
+20:29:40.5 |
HIP 75249 |
27.75 |
| 2026-06-21 12:00 |
15:24:25.85 |
+20:29:41.6 |
HIP 75249 |
26.56 |
| 2026-06-22 00:00 |
15:24:20.70 |
+20:29:42.1 |
HIP 75249 |
25.39 |