| 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) |
| 2026-09-20 00:00 |
23:12:21.13 |
+57:31:14.5 |
HIP 114406 |
18.21 |
| 2026-09-20 12:00 |
23:12:08.92 |
+57:30:06.1 |
HIP 114406 |
16.37 |
| 2026-09-21 00:00 |
23:11:56.74 |
+57:28:56.7 |
HIP 114406 |
14.56 |
| 2026-09-21 12:00 |
23:11:44.60 |
+57:27:46.2 |
HIP 114406 |
12.82 |
| 2026-09-22 00:00 |
23:11:32.50 |
+57:26:34.7 |
HIP 114406 |
11.17 |
| 2026-09-22 12:00 |
23:11:20.44 |
+57:25:22.1 |
HIP 114406 |
9.67 |
| 2026-09-23 00:00 |
23:11:08.43 |
+57:24:08.4 |
HIP 114406 |
8.40 |
| 2026-09-23 12:00 |
23:10:56.47 |
+57:22:53.7 |
HIP 114406 |
7.49 |
| 2026-09-24 00:00 |
23:10:44.55 |
+57:21:38.0 |
HIP 114406 |
7.08 |
| 2026-09-24 12:00 |
23:10:32.68 |
+57:20:21.2 |
HIP 114406 |
7.26 |
| 2026-09-25 00:00 |
23:10:20.85 |
+57:19:03.4 |
HIP 114406 |
7.99 |
| 2026-09-25 12:00 |
23:10:09.08 |
+57:17:44.6 |
HIP 114406 |
9.16 |
| 2026-09-26 00:00 |
23:09:57.37 |
+57:16:24.8 |
HIP 114406 |
10.62 |
| 2026-09-26 12:00 |
23:09:45.70 |
+57:15:04.0 |
HIP 114259 |
11.91 |
| 2026-09-27 00:00 |
23:09:34.09 |
+57:13:42.1 |
HIP 114259 |
9.98 |
| 2026-09-27 12:00 |
23:09:22.54 |
+57:12:19.3 |
HIP 114259 |
8.13 |
| 2026-09-28 00:00 |
23:09:11.04 |
+57:10:55.5 |
HIP 114259 |
6.43 |
| 2026-09-28 12:00 |
23:08:59.60 |
+57:09:30.7 |
HIP 114259 |
5.04 |
| 2026-09-29 00:00 |
23:08:48.22 |
+57:08:04.9 |
HIP 114259 |
4.30 |
| 2026-09-29 12:00 |
23:08:36.91 |
+57:06:38.1 |
HIP 114259 |
4.53 |
| 2026-09-30 00:00 |
23:08:25.65 |
+57:05:10.4 |
HIP 114259 |
5.62 |
| 2026-09-30 12:00 |
23:08:14.46 |
+57:03:41.7 |
HIP 114259 |
7.20 |
| 2026-10-01 00:00 |
23:08:03.33 |
+57:02:12.0 |
HIP 114259 |
9.02 |
| 2026-10-01 12:00 |
23:07:52.27 |
+57:00:41.4 |
HIP 114259 |
10.96 |
| 2026-10-02 00:00 |
23:07:41.28 |
+56:59:09.8 |
HIP 114259 |
12.97 |
| 2026-10-02 12:00 |
23:07:30.36 |
+56:57:37.3 |
HIP 114259 |
15.02 |
| 2026-10-03 00:00 |
23:07:19.51 |
+56:56:03.9 |
HIP 114259 |
17.11 |
| 2026-10-03 12:00 |
23:07:08.72 |
+56:54:29.6 |
HIP 114259 |
19.21 |
| 2026-10-04 00:00 |
23:06:58.01 |
+56:52:54.3 |
HIP 113975 |
20.34 |
| 2026-10-04 12:00 |
23:06:47.38 |
+56:51:18.1 |
HIP 113975 |
18.25 |
| 2026-10-05 00:00 |
23:06:36.82 |
+56:49:41.0 |
HIP 113975 |
16.17 |
| 2026-10-05 12:00 |
23:06:26.33 |
+56:48:03.0 |
HIP 113975 |
14.12 |
| 2026-10-06 00:00 |
23:06:15.92 |
+56:46:24.2 |
HIP 113975 |
12.12 |
| 2026-10-06 12:00 |
23:06:05.60 |
+56:44:44.4 |
HIP 113975 |
10.19 |
| 2026-10-07 00:00 |
23:05:55.35 |
+56:43:03.8 |
HIP 113975 |
8.40 |
| 2026-10-07 12:00 |
23:05:45.18 |
+56:41:22.3 |
HIP 113975 |
6.85 |
| 2026-10-08 00:00 |
23:05:35.10 |
+56:39:39.9 |
HIP 113975 |
5.74 |
| 2026-10-08 12:00 |
23:05:25.09 |
+56:37:56.7 |
HIP 113975 |
5.38 |
| 2026-10-09 00:00 |
23:05:15.18 |
+56:36:12.7 |
HIP 113975 |
5.89 |
| 2026-10-09 12:00 |
23:05:05.35 |
+56:34:27.8 |
HIP 113975 |
7.11 |
| 2026-10-10 00:00 |
23:04:55.60 |
+56:32:42.1 |
HIP 113939 |
6.76 |
| 2026-10-10 12:00 |
23:04:45.95 |
+56:30:55.6 |
HIP 113939 |
4.54 |
| 2026-10-11 00:00 |
23:04:36.38 |
+56:29:08.3 |
HIP 113939 |
2.32 |