| 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) |
| 2026-07-29 00:00 |
15:20:41.48 |
+20:03:36.6 |
HIP 75249 |
33.48 |
| 2026-07-29 12:00 |
15:20:40.95 |
+20:02:58.2 |
HIP 75249 |
33.97 |
| 2026-07-30 00:00 |
15:20:40.49 |
+20:02:19.4 |
HIP 75249 |
34.45 |
| 2026-07-30 12:00 |
15:20:40.09 |
+20:01:40.3 |
HIP 75249 |
34.93 |
| 2026-07-31 00:00 |
15:20:39.77 |
+20:01:00.9 |
HIP 75249 |
35.41 |
| 2026-07-31 12:00 |
15:20:39.51 |
+20:00:21.2 |
HIP 75249 |
35.89 |
| 2026-08-01 00:00 |
15:20:39.32 |
+19:59:41.2 |
HIP 75249 |
36.36 |
| 2026-08-01 12:00 |
15:20:39.20 |
+19:59:00.8 |
HIP 75249 |
36.83 |
| 2026-08-02 00:00 |
15:20:39.15 |
+19:58:20.2 |
HIP 75249 |
37.30 |
| 2026-08-02 12:00 |
15:20:39.16 |
+19:57:39.3 |
HIP 75249 |
37.77 |
| 2026-08-03 00:00 |
15:20:39.24 |
+19:56:58.1 |
HIP 75249 |
38.24 |
| 2026-08-03 12:00 |
15:20:39.40 |
+19:56:16.5 |
HIP 75249 |
38.70 |
| 2026-08-04 00:00 |
15:20:39.62 |
+19:55:34.7 |
HIP 75249 |
39.16 |
| 2026-08-04 12:00 |
15:20:39.91 |
+19:54:52.7 |
HIP 75249 |
39.63 |
| 2026-08-05 00:00 |
15:20:40.26 |
+19:54:10.3 |
HIP 75249 |
40.09 |
| 2026-08-05 12:00 |
15:20:40.69 |
+19:53:27.7 |
HIP 75249 |
40.55 |
| 2026-08-06 00:00 |
15:20:41.18 |
+19:52:44.8 |
HIP 75249 |
41.02 |
| 2026-08-06 12:00 |
15:20:41.74 |
+19:52:01.7 |
HIP 75249 |
41.48 |
| 2026-08-07 00:00 |
15:20:42.37 |
+19:51:18.3 |
HIP 75249 |
41.94 |
| 2026-08-07 12:00 |
15:20:43.07 |
+19:50:34.7 |
HIP 75249 |
42.41 |
| 2026-08-08 00:00 |
15:20:43.84 |
+19:49:50.8 |
HIP 75191 |
42.62 |
| 2026-08-08 12:00 |
15:20:44.68 |
+19:49:06.7 |
HIP 75191 |
41.87 |
| 2026-08-09 00:00 |
15:20:45.58 |
+19:48:22.3 |
HIP 75191 |
41.11 |
| 2026-08-09 12:00 |
15:20:46.56 |
+19:47:37.7 |
HIP 75191 |
40.34 |
| 2026-08-10 00:00 |
15:20:47.60 |
+19:46:52.9 |
HIP 75191 |
39.56 |
| 2026-08-10 12:00 |
15:20:48.71 |
+19:46:07.9 |
HIP 75191 |
38.76 |
| 2026-08-11 00:00 |
15:20:49.89 |
+19:45:22.7 |
HIP 75191 |
37.96 |
| 2026-08-11 12:00 |
15:20:51.13 |
+19:44:37.3 |
HIP 75191 |
37.15 |
| 2026-08-12 00:00 |
15:20:52.45 |
+19:43:51.6 |
HIP 75191 |
36.33 |
| 2026-08-12 12:00 |
15:20:53.83 |
+19:43:05.8 |
HIP 75191 |
35.50 |
| 2026-08-13 00:00 |
15:20:55.28 |
+19:42:19.8 |
HIP 75191 |
34.66 |
| 2026-08-13 12:00 |
15:20:56.80 |
+19:41:33.6 |
HIP 75191 |
33.81 |
| 2026-08-14 00:00 |
15:20:58.39 |
+19:40:47.2 |
HIP 75191 |
32.96 |
| 2026-08-14 12:00 |
15:21:00.05 |
+19:40:00.7 |
HIP 75191 |
32.09 |
| 2026-08-15 00:00 |
15:21:01.77 |
+19:39:14.0 |
HIP 75191 |
31.21 |
| 2026-08-15 12:00 |
15:21:03.56 |
+19:38:27.2 |
HIP 75191 |
30.33 |
| 2026-08-16 00:00 |
15:21:05.42 |
+19:37:40.1 |
HIP 75191 |
29.43 |
| 2026-08-16 12:00 |
15:21:07.34 |
+19:36:53.0 |
HIP 75191 |
28.53 |
| 2026-08-17 00:00 |
15:21:09.34 |
+19:36:05.7 |
HIP 75191 |
27.62 |
| 2026-08-17 12:00 |
15:21:11.40 |
+19:35:18.3 |
HIP 75191 |
26.70 |
| 2026-08-18 00:00 |
15:21:13.52 |
+19:34:30.7 |
HIP 75191 |
25.78 |
| 2026-08-18 12:00 |
15:21:15.71 |
+19:33:43.0 |
HIP 75191 |
24.85 |
| 2026-08-19 00:00 |
15:21:17.97 |
+19:32:55.2 |
HIP 75191 |
23.91 |