| 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 |
1.000 |
| gb |
-0.826 |
| 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 |
+6.7895 |
-4.410 |
| 2021-12-16 |
2023-03-02 |
-3.6428 |
+2.331 |
| 2023-03-02 |
2024-01-08 |
+10.1727 |
-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) |
| 2026-07-29 00:00 |
23:32:20.71 |
+57:47:12.3 |
HIP 116210 |
7.98 |
| 2026-07-29 12:00 |
23:32:12.85 |
+57:47:57.5 |
HIP 116210 |
7.88 |
| 2026-07-30 00:00 |
23:32:04.88 |
+57:48:41.8 |
HIP 116210 |
8.01 |
| 2026-07-30 12:00 |
23:31:56.80 |
+57:49:25.2 |
HIP 116210 |
8.36 |
| 2026-07-31 00:00 |
23:31:48.62 |
+57:50:07.7 |
HIP 116210 |
8.90 |
| 2026-07-31 12:00 |
23:31:40.35 |
+57:50:49.4 |
HIP 116210 |
9.61 |
| 2026-08-01 00:00 |
23:31:31.97 |
+57:51:30.1 |
HIP 116210 |
10.45 |
| 2026-08-01 12:00 |
23:31:23.49 |
+57:52:10.0 |
HIP 116018 |
9.82 |
| 2026-08-02 00:00 |
23:31:14.91 |
+57:52:49.0 |
HIP 116018 |
8.53 |
| 2026-08-02 12:00 |
23:31:06.23 |
+57:53:27.0 |
HIP 116018 |
7.26 |
| 2026-08-03 00:00 |
23:30:57.46 |
+57:54:04.2 |
HIP 116018 |
6.01 |
| 2026-08-03 12:00 |
23:30:48.59 |
+57:54:40.4 |
HIP 116018 |
4.80 |
| 2026-08-04 00:00 |
23:30:39.62 |
+57:55:15.7 |
HIP 116018 |
3.68 |
| 2026-08-04 12:00 |
23:30:30.56 |
+57:55:50.0 |
HIP 116018 |
2.76 |
| 2026-08-05 00:00 |
23:30:21.40 |
+57:56:23.4 |
HIP 116018 |
2.31 |
| 2026-08-05 12:00 |
23:30:12.15 |
+57:56:55.9 |
HIP 116018 |
2.60 |
| 2026-08-06 00:00 |
23:30:02.80 |
+57:57:27.4 |
HIP 116018 |
3.44 |
| 2026-08-06 12:00 |
23:29:53.37 |
+57:57:58.0 |
HIP 116018 |
4.55 |
| 2026-08-07 00:00 |
23:29:43.84 |
+57:58:27.5 |
HIP 116018 |
5.77 |
| 2026-08-07 12:00 |
23:29:34.22 |
+57:58:56.1 |
HIP 116018 |
7.06 |
| 2026-08-08 00:00 |
23:29:24.52 |
+57:59:23.8 |
HIP 116018 |
8.37 |
| 2026-08-08 12:00 |
23:29:14.73 |
+57:59:50.4 |
HIP 116018 |
9.71 |
| 2026-08-09 00:00 |
23:29:04.85 |
+58:00:16.1 |
HIP 116018 |
11.07 |
| 2026-08-09 12:00 |
23:28:54.88 |
+58:00:40.7 |
HIP 116018 |
12.44 |
| 2026-08-10 00:00 |
23:28:44.83 |
+58:01:04.4 |
HIP 116018 |
13.82 |
| 2026-08-10 12:00 |
23:28:34.70 |
+58:01:27.0 |
HIP 116018 |
15.20 |
| 2026-08-11 00:00 |
23:28:24.48 |
+58:01:48.6 |
HIP 116018 |
16.60 |
| 2026-08-11 12:00 |
23:28:14.18 |
+58:02:09.2 |
HIP 116018 |
18.00 |
| 2026-08-12 00:00 |
23:28:03.80 |
+58:02:28.8 |
HIP 116018 |
19.42 |
| 2026-08-12 12:00 |
23:27:53.35 |
+58:02:47.4 |
HIP 116018 |
20.83 |
| 2026-08-13 00:00 |
23:27:42.81 |
+58:03:04.9 |
HIP 116018 |
22.26 |
| 2026-08-13 12:00 |
23:27:32.20 |
+58:03:21.3 |
HIP 116018 |
23.69 |
| 2026-08-14 00:00 |
23:27:21.51 |
+58:03:36.7 |
HIP 116018 |
25.12 |
| 2026-08-14 12:00 |
23:27:10.75 |
+58:03:51.1 |
HIP 115562 |
24.67 |
| 2026-08-15 00:00 |
23:26:59.92 |
+58:04:04.4 |
HIP 115562 |
23.57 |
| 2026-08-15 12:00 |
23:26:49.02 |
+58:04:16.6 |
HIP 115562 |
22.48 |
| 2026-08-16 00:00 |
23:26:38.05 |
+58:04:27.8 |
HIP 115562 |
21.42 |
| 2026-08-16 12:00 |
23:26:27.00 |
+58:04:37.9 |
HIP 115562 |
20.40 |
| 2026-08-17 00:00 |
23:26:15.89 |
+58:04:46.9 |
HIP 115562 |
19.41 |
| 2026-08-17 12:00 |
23:26:04.72 |
+58:04:54.9 |
HIP 115562 |
18.47 |
| 2026-08-18 00:00 |
23:25:53.48 |
+58:05:01.8 |
HIP 115562 |
17.59 |
| 2026-08-18 12:00 |
23:25:42.18 |
+58:05:07.6 |
HIP 115562 |
16.77 |
| 2026-08-19 00:00 |
23:25:30.82 |
+58:05:12.3 |
HIP 115562 |
16.03 |