| Parameter |
Value |
| Designation |
C/2020 M3 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-10-25T14:58:23.448000Z |
| Orbit solution date (soln_date, UTC) |
2022-04-23T03:12:26Z |
| Obs used |
2344 |
| NEO |
Yes |
| M1 |
14.600 |
| K1 |
6.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-06-27T13:57:10.627200Z |
| Discovery magnitude (MPC) |
18.89 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-11-26.0000000 |
| e |
0.95270763 |
| q (au) |
1.268249 |
| a (au) |
26.817195 |
| i (deg) |
23.473528 |
| Ω (om, deg) |
71.250235 |
| ω (w, deg) |
328.446314 |
| M (ma, deg) |
0.222681 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.015 + 2.681\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.015 |
| n |
2.681 |
| gf |
0.993 |
| gb |
-1.000 |
| k |
0.999 |
| δ90 |
1.000 |
| 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 |
| 2012-01-10 |
2020-08-06 |
-14.0320 |
+4.994 |
| 2020-08-06 |
2020-10-25 |
+30.0861 |
-5.641 |
| 2020-10-25 |
2021-06-10 |
+4.2695 |
-2.068 |
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 |
13:24:17.40 |
+14:31:43.4 |
HIP 65427 |
20.25 |
| 2026-03-26 12:00 |
13:24:10.43 |
+14:32:31.7 |
HIP 65427 |
19.95 |
| 2026-03-27 00:00 |
13:24:03.44 |
+14:33:19.6 |
HIP 65427 |
19.82 |
| 2026-03-27 12:00 |
13:23:56.43 |
+14:34:07.1 |
HIP 65427 |
19.88 |
| 2026-03-28 00:00 |
13:23:49.40 |
+14:34:54.4 |
HIP 65427 |
20.12 |
| 2026-03-28 12:00 |
13:23:42.36 |
+14:35:41.3 |
HIP 65427 |
20.54 |
| 2026-03-29 00:00 |
13:23:35.30 |
+14:36:27.8 |
HIP 65427 |
21.12 |
| 2026-03-29 12:00 |
13:23:28.22 |
+14:37:14.0 |
HIP 65427 |
21.86 |
| 2026-03-30 00:00 |
13:23:21.13 |
+14:37:59.9 |
HIP 65427 |
22.73 |
| 2026-03-30 12:00 |
13:23:14.02 |
+14:38:45.4 |
HIP 65427 |
23.73 |
| 2026-03-31 00:00 |
13:23:06.89 |
+14:39:30.5 |
HIP 65427 |
24.83 |
| 2026-03-31 12:00 |
13:22:59.76 |
+14:40:15.3 |
HIP 65427 |
26.03 |
| 2026-04-01 00:00 |
13:22:52.61 |
+14:40:59.7 |
HIP 65427 |
27.31 |
| 2026-04-01 12:00 |
13:22:45.44 |
+14:41:43.7 |
HIP 65427 |
28.66 |
| 2026-04-02 00:00 |
13:22:38.27 |
+14:42:27.3 |
HIP 65427 |
30.07 |
| 2026-04-02 12:00 |
13:22:31.08 |
+14:43:10.6 |
HIP 65427 |
31.54 |
| 2026-04-03 00:00 |
13:22:23.89 |
+14:43:53.5 |
HIP 65300 |
32.34 |
| 2026-04-03 12:00 |
13:22:16.68 |
+14:44:36.0 |
HIP 65300 |
32.18 |
| 2026-04-04 00:00 |
13:22:09.47 |
+14:45:18.1 |
HIP 65300 |
32.13 |
| 2026-04-04 12:00 |
13:22:02.25 |
+14:45:59.8 |
HIP 65300 |
32.21 |
| 2026-04-05 00:00 |
13:21:55.02 |
+14:46:41.1 |
HIP 65300 |
32.39 |
| 2026-04-05 12:00 |
13:21:47.78 |
+14:47:22.0 |
HIP 65300 |
32.70 |
| 2026-04-06 00:00 |
13:21:40.53 |
+14:48:02.5 |
HIP 65300 |
33.11 |
| 2026-04-06 12:00 |
13:21:33.29 |
+14:48:42.5 |
HIP 65300 |
33.63 |
| 2026-04-07 00:00 |
13:21:26.03 |
+14:49:22.2 |
HIP 65300 |
34.24 |
| 2026-04-07 12:00 |
13:21:18.77 |
+14:50:01.4 |
HIP 65300 |
34.96 |
| 2026-04-08 00:00 |
13:21:11.51 |
+14:50:40.2 |
HIP 65300 |
35.76 |
| 2026-04-08 12:00 |
13:21:04.25 |
+14:51:18.6 |
HIP 65300 |
36.65 |
| 2026-04-09 00:00 |
13:20:56.98 |
+14:51:56.6 |
HIP 65080 |
36.16 |
| 2026-04-09 12:00 |
13:20:49.71 |
+14:52:34.1 |
HIP 65080 |
35.20 |
| 2026-04-10 00:00 |
13:20:42.44 |
+14:53:11.2 |
HIP 65080 |
34.32 |
| 2026-04-10 12:00 |
13:20:35.17 |
+14:53:47.8 |
HIP 65080 |
33.52 |
| 2026-04-11 00:00 |
13:20:27.90 |
+14:54:24.0 |
HIP 65080 |
32.82 |
| 2026-04-11 12:00 |
13:20:20.64 |
+14:54:59.8 |
HIP 65080 |
32.21 |
| 2026-04-12 00:00 |
13:20:13.37 |
+14:55:35.0 |
HIP 65080 |
31.71 |
| 2026-04-12 12:00 |
13:20:06.11 |
+14:56:09.9 |
HIP 65080 |
31.32 |
| 2026-04-13 00:00 |
13:19:58.85 |
+14:56:44.2 |
HIP 65080 |
31.04 |
| 2026-04-13 12:00 |
13:19:51.60 |
+14:57:18.2 |
HIP 65080 |
30.88 |
| 2026-04-14 00:00 |
13:19:44.35 |
+14:57:51.6 |
HIP 65080 |
30.83 |
| 2026-04-14 12:00 |
13:19:37.10 |
+14:58:24.6 |
HIP 65080 |
30.90 |
| 2026-04-15 00:00 |
13:19:29.86 |
+14:58:57.1 |
HIP 65080 |
31.08 |
| 2026-04-15 12:00 |
13:19:22.63 |
+14:59:29.1 |
HIP 65080 |
31.38 |
| 2026-04-16 00:00 |
13:19:15.41 |
+15:00:00.6 |
HIP 65080 |
31.78 |