| Parameter |
Value |
| Designation |
C/2020 H6 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-10-01T01:15:36.267840Z |
| Orbit solution date (soln_date, UTC) |
2024-05-30T01:12:18Z |
| Obs used |
2087 |
| NEO |
- |
| M1 |
7.400 |
| K1 |
8.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-04-22T08:13:58.051200Z |
| Discovery magnitude (MPC) |
18.18 c |
| Discovery observatory (MPC) |
T05 · ATLAS-HKO, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-01-06.0000000 |
| e |
1.00057173 |
| q (au) |
4.702870 |
| a (au) |
-8225.630152 |
| i (deg) |
79.970760 |
| Ω (om, deg) |
213.708285 |
| ω (w, deg) |
20.344638 |
| M (ma, deg) |
0.000128 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.961 + 3.055\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.961 |
| n |
3.055 |
| gf |
0.999 |
| gb |
-0.515 |
| 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 |
| 2020-04-22 |
2021-08-23 |
+6.7896 |
-4.410 |
| 2021-12-16 |
2023-03-02 |
-3.6427 |
+2.331 |
| 2023-03-02 |
2024-01-08 |
+10.1728 |
-8.400 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
23:28:48.46 |
+54:10:12.5 |
HIP 116113 |
24.81 |
| 2026-05-12 12:00 |
23:28:58.43 |
+54:11:45.1 |
HIP 116113 |
23.51 |
| 2026-05-13 00:00 |
23:29:08.30 |
+54:13:17.9 |
HIP 116113 |
22.35 |
| 2026-05-13 12:00 |
23:29:18.09 |
+54:14:51.0 |
HIP 116113 |
21.36 |
| 2026-05-14 00:00 |
23:29:27.78 |
+54:16:24.2 |
HIP 116113 |
20.56 |
| 2026-05-14 12:00 |
23:29:37.37 |
+54:17:57.7 |
HIP 116113 |
19.96 |
| 2026-05-15 00:00 |
23:29:46.87 |
+54:19:31.3 |
HIP 116113 |
19.58 |
| 2026-05-15 12:00 |
23:29:56.28 |
+54:21:05.2 |
HIP 116113 |
19.44 |
| 2026-05-16 00:00 |
23:30:05.59 |
+54:22:39.2 |
HIP 116113 |
19.53 |
| 2026-05-16 12:00 |
23:30:14.81 |
+54:24:13.4 |
HIP 116113 |
19.85 |
| 2026-05-17 00:00 |
23:30:23.93 |
+54:25:47.8 |
HIP 116113 |
20.39 |
| 2026-05-17 12:00 |
23:30:32.95 |
+54:27:22.4 |
HIP 116113 |
21.12 |
| 2026-05-18 00:00 |
23:30:41.87 |
+54:28:57.1 |
HIP 116113 |
22.03 |
| 2026-05-18 12:00 |
23:30:50.70 |
+54:30:32.0 |
HIP 116113 |
23.10 |
| 2026-05-19 00:00 |
23:30:59.43 |
+54:32:07.0 |
HIP 116291 |
23.57 |
| 2026-05-19 12:00 |
23:31:08.06 |
+54:33:42.1 |
HIP 116291 |
22.47 |
| 2026-05-20 00:00 |
23:31:16.59 |
+54:35:17.4 |
HIP 116149 |
20.89 |
| 2026-05-20 12:00 |
23:31:25.02 |
+54:36:52.8 |
HIP 116149 |
19.02 |
| 2026-05-21 00:00 |
23:31:33.35 |
+54:38:28.3 |
HIP 116149 |
17.19 |
| 2026-05-21 12:00 |
23:31:41.58 |
+54:40:04.0 |
HIP 116149 |
15.40 |
| 2026-05-22 00:00 |
23:31:49.71 |
+54:41:39.7 |
HIP 116149 |
13.66 |
| 2026-05-22 12:00 |
23:31:57.73 |
+54:43:15.6 |
HIP 116149 |
11.99 |
| 2026-05-23 00:00 |
23:32:05.66 |
+54:44:51.5 |
HIP 116149 |
10.43 |
| 2026-05-23 12:00 |
23:32:13.48 |
+54:46:27.5 |
HIP 116149 |
9.03 |
| 2026-05-24 00:00 |
23:32:21.20 |
+54:48:03.6 |
HIP 116149 |
7.85 |
| 2026-05-24 12:00 |
23:32:28.81 |
+54:49:39.8 |
HIP 116149 |
7.02 |
| 2026-05-25 00:00 |
23:32:36.32 |
+54:51:16.1 |
HIP 116149 |
6.65 |
| 2026-05-25 12:00 |
23:32:43.73 |
+54:52:52.4 |
HIP 116149 |
6.82 |
| 2026-05-26 00:00 |
23:32:51.04 |
+54:54:28.7 |
HIP 116149 |
7.48 |
| 2026-05-26 12:00 |
23:32:58.24 |
+54:56:05.1 |
HIP 116149 |
8.51 |
| 2026-05-27 00:00 |
23:33:05.33 |
+54:57:41.6 |
HIP 116149 |
9.79 |
| 2026-05-27 12:00 |
23:33:12.32 |
+54:59:18.1 |
HIP 116149 |
11.24 |
| 2026-05-28 00:00 |
23:33:19.20 |
+55:00:54.6 |
HIP 116149 |
12.79 |
| 2026-05-28 12:00 |
23:33:25.98 |
+55:02:31.2 |
HIP 116149 |
14.40 |
| 2026-05-29 00:00 |
23:33:32.65 |
+55:04:07.7 |
HIP 116149 |
16.07 |
| 2026-05-29 12:00 |
23:33:39.21 |
+55:05:44.3 |
HIP 116149 |
17.75 |
| 2026-05-30 00:00 |
23:33:45.67 |
+55:07:20.9 |
HIP 116149 |
19.46 |
| 2026-05-30 12:00 |
23:33:52.01 |
+55:08:57.5 |
HIP 116324 |
20.52 |
| 2026-05-31 00:00 |
23:33:58.25 |
+55:10:34.1 |
HIP 116324 |
18.82 |
| 2026-05-31 12:00 |
23:34:04.38 |
+55:12:10.7 |
HIP 116324 |
17.16 |
| 2026-06-01 00:00 |
23:34:10.40 |
+55:13:47.3 |
HIP 116324 |
15.54 |
| 2026-06-01 12:00 |
23:34:16.31 |
+55:15:23.8 |
HIP 116324 |
13.97 |
| 2026-06-02 00:00 |
23:34:22.12 |
+55:17:00.3 |
HIP 116324 |
12.46 |