| 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) |
| 2026-06-01 00:00 |
13:10:07.97 |
+15:10:58.1 |
HIP 64255 |
2.12 |
| 2026-06-01 12:00 |
13:10:04.03 |
+15:10:40.8 |
HIP 64255 |
2.60 |
| 2026-06-02 00:00 |
13:10:00.15 |
+15:10:22.9 |
HIP 64255 |
3.31 |
| 2026-06-02 12:00 |
13:09:56.32 |
+15:10:04.5 |
HIP 64255 |
4.11 |
| 2026-06-03 00:00 |
13:09:52.54 |
+15:09:45.7 |
HIP 64255 |
4.96 |
| 2026-06-03 12:00 |
13:09:48.82 |
+15:09:26.4 |
HIP 64255 |
5.84 |
| 2026-06-04 00:00 |
13:09:45.16 |
+15:09:06.6 |
HIP 64255 |
6.72 |
| 2026-06-04 12:00 |
13:09:41.55 |
+15:08:46.3 |
HIP 64255 |
7.60 |
| 2026-06-05 00:00 |
13:09:38.00 |
+15:08:25.5 |
HIP 64255 |
8.48 |
| 2026-06-05 12:00 |
13:09:34.51 |
+15:08:04.2 |
HIP 64255 |
9.36 |
| 2026-06-06 00:00 |
13:09:31.07 |
+15:07:42.5 |
HIP 64255 |
10.23 |
| 2026-06-06 12:00 |
13:09:27.69 |
+15:07:20.3 |
HIP 64255 |
11.10 |
| 2026-06-07 00:00 |
13:09:24.36 |
+15:06:57.6 |
HIP 64255 |
11.95 |
| 2026-06-07 12:00 |
13:09:21.10 |
+15:06:34.5 |
HIP 64255 |
12.80 |
| 2026-06-08 00:00 |
13:09:17.89 |
+15:06:10.8 |
HIP 64255 |
13.65 |
| 2026-06-08 12:00 |
13:09:14.73 |
+15:05:46.7 |
HIP 64255 |
14.48 |
| 2026-06-09 00:00 |
13:09:11.64 |
+15:05:22.2 |
HIP 64255 |
15.30 |
| 2026-06-09 12:00 |
13:09:08.61 |
+15:04:57.2 |
HIP 64255 |
16.12 |
| 2026-06-10 00:00 |
13:09:05.63 |
+15:04:31.7 |
HIP 64255 |
16.93 |
| 2026-06-10 12:00 |
13:09:02.71 |
+15:04:05.8 |
HIP 64255 |
17.72 |
| 2026-06-11 00:00 |
13:08:59.85 |
+15:03:39.4 |
HIP 64255 |
18.51 |
| 2026-06-11 12:00 |
13:08:57.05 |
+15:03:12.5 |
HIP 64255 |
19.29 |
| 2026-06-12 00:00 |
13:08:54.31 |
+15:02:45.2 |
HIP 64255 |
20.07 |
| 2026-06-12 12:00 |
13:08:51.63 |
+15:02:17.5 |
HIP 64255 |
20.83 |
| 2026-06-13 00:00 |
13:08:49.00 |
+15:01:49.3 |
HIP 64255 |
21.58 |
| 2026-06-13 12:00 |
13:08:46.44 |
+15:01:20.7 |
HIP 64255 |
22.33 |
| 2026-06-14 00:00 |
13:08:43.94 |
+15:00:51.6 |
HIP 64255 |
23.07 |
| 2026-06-14 12:00 |
13:08:41.50 |
+15:00:22.0 |
HIP 64255 |
23.80 |
| 2026-06-15 00:00 |
13:08:39.11 |
+14:59:52.1 |
HIP 64255 |
24.52 |
| 2026-06-15 12:00 |
13:08:36.79 |
+14:59:21.7 |
HIP 64255 |
25.23 |
| 2026-06-16 00:00 |
13:08:34.53 |
+14:58:50.9 |
HIP 64255 |
25.94 |
| 2026-06-16 12:00 |
13:08:32.33 |
+14:58:19.6 |
HIP 64255 |
26.64 |
| 2026-06-17 00:00 |
13:08:30.18 |
+14:57:47.9 |
HIP 64255 |
27.33 |
| 2026-06-17 12:00 |
13:08:28.10 |
+14:57:15.9 |
HIP 64255 |
28.01 |
| 2026-06-18 00:00 |
13:08:26.08 |
+14:56:43.3 |
HIP 64255 |
28.68 |
| 2026-06-18 12:00 |
13:08:24.12 |
+14:56:10.4 |
HIP 64255 |
29.35 |
| 2026-06-19 00:00 |
13:08:22.23 |
+14:55:37.1 |
HIP 64255 |
30.01 |
| 2026-06-19 12:00 |
13:08:20.39 |
+14:55:03.3 |
HIP 64255 |
30.66 |
| 2026-06-20 00:00 |
13:08:18.61 |
+14:54:29.2 |
HIP 64255 |
31.31 |
| 2026-06-20 12:00 |
13:08:16.90 |
+14:53:54.6 |
HIP 64255 |
31.95 |
| 2026-06-21 00:00 |
13:08:15.24 |
+14:53:19.6 |
HIP 64255 |
32.58 |
| 2026-06-21 12:00 |
13:08:13.65 |
+14:52:44.3 |
HIP 63923 |
32.55 |
| 2026-06-22 00:00 |
13:08:12.12 |
+14:52:08.5 |
HIP 63923 |
32.14 |