| 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) |
| 2026-03-26 00:00 |
23:07:38.56 |
+52:14:29.8 |
HIP 114083 |
13.03 |
| 2026-03-26 12:00 |
23:07:54.75 |
+52:15:18.0 |
HIP 114083 |
15.63 |
| 2026-03-27 00:00 |
23:08:10.89 |
+52:16:06.8 |
HIP 114083 |
18.22 |
| 2026-03-27 12:00 |
23:08:27.00 |
+52:16:56.4 |
HIP 114083 |
20.81 |
| 2026-03-28 00:00 |
23:08:43.06 |
+52:17:46.6 |
HIP 114317 |
19.71 |
| 2026-03-28 12:00 |
23:08:59.08 |
+52:18:37.5 |
HIP 114317 |
18.59 |
| 2026-03-29 00:00 |
23:09:15.05 |
+52:19:29.1 |
HIP 114317 |
17.76 |
| 2026-03-29 12:00 |
23:09:30.98 |
+52:20:21.4 |
HIP 114317 |
17.28 |
| 2026-03-30 00:00 |
23:09:46.87 |
+52:21:14.3 |
HIP 114317 |
17.15 |
| 2026-03-30 12:00 |
23:10:02.71 |
+52:22:07.9 |
HIP 114317 |
17.40 |
| 2026-03-31 00:00 |
23:10:18.51 |
+52:23:02.2 |
HIP 114317 |
18.00 |
| 2026-03-31 12:00 |
23:10:34.27 |
+52:23:57.1 |
HIP 114317 |
18.92 |
| 2026-04-01 00:00 |
23:10:49.97 |
+52:24:52.6 |
HIP 114559 |
17.74 |
| 2026-04-01 12:00 |
23:11:05.63 |
+52:25:48.8 |
HIP 114559 |
16.61 |
| 2026-04-02 00:00 |
23:11:21.25 |
+52:26:45.7 |
HIP 114559 |
15.83 |
| 2026-04-02 12:00 |
23:11:36.81 |
+52:27:43.2 |
HIP 114559 |
15.46 |
| 2026-04-03 00:00 |
23:11:52.33 |
+52:28:41.3 |
HIP 114559 |
15.52 |
| 2026-04-03 12:00 |
23:12:07.80 |
+52:29:40.0 |
HIP 114559 |
16.01 |
| 2026-04-04 00:00 |
23:12:23.22 |
+52:30:39.4 |
HIP 114559 |
16.88 |
| 2026-04-04 12:00 |
23:12:38.58 |
+52:31:39.3 |
HIP 114559 |
18.09 |
| 2026-04-05 00:00 |
23:12:53.90 |
+52:32:39.9 |
HIP 114559 |
19.56 |
| 2026-04-05 12:00 |
23:13:09.17 |
+52:33:41.1 |
HIP 114559 |
21.25 |
| 2026-04-06 00:00 |
23:13:24.39 |
+52:34:43.0 |
HIP 114796 |
21.44 |
| 2026-04-06 12:00 |
23:13:39.56 |
+52:35:45.4 |
HIP 114796 |
20.44 |
| 2026-04-07 00:00 |
23:13:54.67 |
+52:36:48.4 |
HIP 114796 |
19.73 |
| 2026-04-07 12:00 |
23:14:09.73 |
+52:37:52.0 |
HIP 114796 |
19.34 |
| 2026-04-08 00:00 |
23:14:24.74 |
+52:38:56.2 |
HIP 114796 |
19.29 |
| 2026-04-08 12:00 |
23:14:39.69 |
+52:40:01.0 |
HIP 114796 |
19.58 |
| 2026-04-09 00:00 |
23:14:54.59 |
+52:41:06.4 |
HIP 114796 |
20.19 |
| 2026-04-09 12:00 |
23:15:09.43 |
+52:42:12.3 |
HIP 114796 |
21.10 |
| 2026-04-10 00:00 |
23:15:24.22 |
+52:43:18.9 |
HIP 114796 |
22.26 |
| 2026-04-10 12:00 |
23:15:38.95 |
+52:44:25.9 |
HIP 114796 |
23.65 |
| 2026-04-11 00:00 |
23:15:53.63 |
+52:45:33.6 |
HIP 114796 |
25.21 |
| 2026-04-11 12:00 |
23:16:08.24 |
+52:46:41.8 |
HIP 114924 |
26.64 |
| 2026-04-12 00:00 |
23:16:22.80 |
+52:47:50.6 |
HIP 114924 |
25.17 |
| 2026-04-12 12:00 |
23:16:37.30 |
+52:49:00.0 |
HIP 114924 |
23.86 |
| 2026-04-13 00:00 |
23:16:51.74 |
+52:50:09.8 |
HIP 114924 |
22.73 |
| 2026-04-13 12:00 |
23:17:06.13 |
+52:51:20.2 |
HIP 114924 |
21.81 |
| 2026-04-14 00:00 |
23:17:20.45 |
+52:52:31.1 |
HIP 114924 |
21.12 |
| 2026-04-14 12:00 |
23:17:34.71 |
+52:53:42.6 |
HIP 114924 |
20.70 |
| 2026-04-15 00:00 |
23:17:48.90 |
+52:54:54.6 |
HIP 114924 |
20.54 |
| 2026-04-15 12:00 |
23:18:03.04 |
+52:56:07.1 |
HIP 115116 |
19.83 |
| 2026-04-16 00:00 |
23:18:17.11 |
+52:57:20.2 |
HIP 115116 |
17.87 |