| 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
$$
M_a = (-1.200 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-1.200 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
+11.5591 |
-11.528 |
| 2020-12-18 |
2023-05-08 |
+14.7277 |
-14.765 |
| 2023-05-08 |
2025-05-02 |
-3.8779 |
+4.668 |
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 |
15:42:19.11 |
+17:28:56.1 |
HIP 77011 |
26.83 |
| 2026-03-26 12:00 |
15:42:15.54 |
+17:30:44.7 |
HIP 76759 |
27.64 |
| 2026-03-27 00:00 |
15:42:11.90 |
+17:32:33.1 |
HIP 76759 |
27.32 |
| 2026-03-27 12:00 |
15:42:08.20 |
+17:34:21.2 |
HIP 76759 |
27.12 |
| 2026-03-28 00:00 |
15:42:04.44 |
+17:36:09.1 |
HIP 76759 |
27.06 |
| 2026-03-28 12:00 |
15:42:00.61 |
+17:37:56.8 |
HIP 76759 |
27.13 |
| 2026-03-29 00:00 |
15:41:56.72 |
+17:39:44.2 |
HIP 76759 |
27.34 |
| 2026-03-29 12:00 |
15:41:52.77 |
+17:41:31.3 |
HIP 76759 |
27.68 |
| 2026-03-30 00:00 |
15:41:48.76 |
+17:43:18.2 |
HIP 76759 |
28.15 |
| 2026-03-30 12:00 |
15:41:44.68 |
+17:45:04.9 |
HIP 76759 |
28.74 |
| 2026-03-31 00:00 |
15:41:40.55 |
+17:46:51.2 |
HIP 76926 |
28.34 |
| 2026-03-31 12:00 |
15:41:36.35 |
+17:48:37.2 |
HIP 76926 |
27.15 |
| 2026-04-01 00:00 |
15:41:32.09 |
+17:50:23.0 |
HIP 76926 |
26.07 |
| 2026-04-01 12:00 |
15:41:27.78 |
+17:52:08.5 |
HIP 76926 |
25.12 |
| 2026-04-02 00:00 |
15:41:23.41 |
+17:53:53.6 |
HIP 76926 |
24.32 |
| 2026-04-02 12:00 |
15:41:18.97 |
+17:55:38.5 |
HIP 76926 |
23.68 |
| 2026-04-03 00:00 |
15:41:14.48 |
+17:57:23.0 |
HIP 76926 |
23.21 |
| 2026-04-03 12:00 |
15:41:09.94 |
+17:59:07.2 |
HIP 76926 |
22.94 |
| 2026-04-04 00:00 |
15:41:05.33 |
+18:00:51.1 |
HIP 76926 |
22.86 |
| 2026-04-04 12:00 |
15:41:00.67 |
+18:02:34.7 |
HIP 76926 |
22.97 |
| 2026-04-05 00:00 |
15:40:55.95 |
+18:04:17.9 |
HIP 76926 |
23.28 |
| 2026-04-05 12:00 |
15:40:51.18 |
+18:06:00.7 |
HIP 76926 |
23.78 |
| 2026-04-06 00:00 |
15:40:46.35 |
+18:07:43.2 |
HIP 76926 |
24.46 |
| 2026-04-06 12:00 |
15:40:41.47 |
+18:09:25.4 |
HIP 76926 |
25.29 |
| 2026-04-07 00:00 |
15:40:36.53 |
+18:11:07.1 |
HIP 76878 |
24.98 |
| 2026-04-07 12:00 |
15:40:31.54 |
+18:12:48.5 |
HIP 76878 |
24.81 |
| 2026-04-08 00:00 |
15:40:26.50 |
+18:14:29.5 |
HIP 76878 |
24.83 |
| 2026-04-08 12:00 |
15:40:21.40 |
+18:16:10.1 |
HIP 76769 |
24.18 |
| 2026-04-09 00:00 |
15:40:16.25 |
+18:17:50.3 |
HIP 76769 |
22.63 |
| 2026-04-09 12:00 |
15:40:11.05 |
+18:19:30.1 |
HIP 76769 |
21.19 |
| 2026-04-10 00:00 |
15:40:05.80 |
+18:21:09.5 |
HIP 76769 |
19.87 |
| 2026-04-10 12:00 |
15:40:00.49 |
+18:22:48.5 |
HIP 76769 |
18.69 |
| 2026-04-11 00:00 |
15:39:55.14 |
+18:24:27.0 |
HIP 76769 |
17.69 |
| 2026-04-11 12:00 |
15:39:49.74 |
+18:26:05.2 |
HIP 76769 |
16.91 |
| 2026-04-12 00:00 |
15:39:44.29 |
+18:27:42.9 |
HIP 76769 |
16.36 |
| 2026-04-12 12:00 |
15:39:38.79 |
+18:29:20.1 |
HIP 76769 |
16.08 |
| 2026-04-13 00:00 |
15:39:33.24 |
+18:30:56.9 |
HIP 76769 |
16.07 |
| 2026-04-13 12:00 |
15:39:27.65 |
+18:32:33.2 |
HIP 76769 |
16.35 |
| 2026-04-14 00:00 |
15:39:22.01 |
+18:34:09.1 |
HIP 76769 |
16.90 |
| 2026-04-14 12:00 |
15:39:16.32 |
+18:35:44.5 |
HIP 76769 |
17.68 |
| 2026-04-15 00:00 |
15:39:10.59 |
+18:37:19.4 |
HIP 76769 |
18.68 |
| 2026-04-15 12:00 |
15:39:04.81 |
+18:38:53.8 |
HIP 76769 |
19.86 |
| 2026-04-16 00:00 |
15:38:58.99 |
+18:40:27.7 |
HIP 76769 |
21.19 |