C/2020 M3 (ATLAS)
| 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
$$
M_a = (14.011 + 2.685\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.011 |
| n |
2.685 |
| gf |
1.000 |
| 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 |
-14.0526 |
+5.000 |
| 2020-08-06 |
2020-10-25 |
+30.0758 |
-5.637 |
| 2020-10-25 |
2021-06-10 |
+4.2220 |
-2.054 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
13:32:32.43 |
+12:57:59.8 |
HIP 66138 |
16.27 |
| 2026-02-03 12:00 |
13:32:30.46 |
+12:58:51.8 |
HIP 66138 |
17.15 |
| 2026-02-04 00:00 |
13:32:28.42 |
+12:59:44.1 |
HIP 66138 |
18.06 |
| 2026-02-04 12:00 |
13:32:26.31 |
+13:00:36.7 |
HIP 66138 |
18.99 |
| 2026-02-05 00:00 |
13:32:24.14 |
+13:01:29.5 |
HIP 66138 |
19.95 |
| 2026-02-05 12:00 |
13:32:21.90 |
+13:02:22.5 |
HIP 66138 |
20.92 |
| 2026-02-06 00:00 |
13:32:19.59 |
+13:03:15.7 |
HIP 66138 |
21.92 |
| 2026-02-06 12:00 |
13:32:17.22 |
+13:04:09.2 |
HIP 66138 |
22.94 |
| 2026-02-07 00:00 |
13:32:14.78 |
+13:05:02.8 |
HIP 66138 |
23.97 |
| 2026-02-07 12:00 |
13:32:12.27 |
+13:05:56.7 |
HIP 66138 |
25.02 |
| 2026-02-08 00:00 |
13:32:09.70 |
+13:06:50.8 |
HIP 66138 |
26.09 |
| 2026-02-08 12:00 |
13:32:07.06 |
+13:07:45.1 |
HIP 66138 |
27.18 |
| 2026-02-09 00:00 |
13:32:04.36 |
+13:08:39.6 |
HIP 65923 |
26.09 |
| 2026-02-09 12:00 |
13:32:01.59 |
+13:09:34.2 |
HIP 65923 |
24.96 |
| 2026-02-10 00:00 |
13:31:58.75 |
+13:10:29.1 |
HIP 65923 |
23.82 |
| 2026-02-10 12:00 |
13:31:55.85 |
+13:11:24.1 |
HIP 65923 |
22.67 |
| 2026-02-11 00:00 |
13:31:52.89 |
+13:12:19.3 |
HIP 65923 |
21.50 |
| 2026-02-11 12:00 |
13:31:49.86 |
+13:13:14.7 |
HIP 65923 |
20.33 |
| 2026-02-12 00:00 |
13:31:46.76 |
+13:14:10.2 |
HIP 65923 |
19.14 |
| 2026-02-12 12:00 |
13:31:43.60 |
+13:15:05.9 |
HIP 65923 |
17.93 |
| 2026-02-13 00:00 |
13:31:40.38 |
+13:16:01.8 |
HIP 65923 |
16.72 |
| 2026-02-13 12:00 |
13:31:37.09 |
+13:16:57.8 |
HIP 65923 |
15.49 |
| 2026-02-14 00:00 |
13:31:33.74 |
+13:17:53.9 |
HIP 65923 |
14.25 |
| 2026-02-14 12:00 |
13:31:30.33 |
+13:18:50.2 |
HIP 65923 |
13.00 |
| 2026-02-15 00:00 |
13:31:26.85 |
+13:19:46.6 |
HIP 65923 |
11.74 |
| 2026-02-15 12:00 |
13:31:23.31 |
+13:20:43.2 |
HIP 65923 |
10.46 |
| 2026-02-16 00:00 |
13:31:19.71 |
+13:21:39.8 |
HIP 65923 |
9.18 |
| 2026-02-16 12:00 |
13:31:16.05 |
+13:22:36.6 |
HIP 65923 |
7.88 |
| 2026-02-17 00:00 |
13:31:12.32 |
+13:23:33.4 |
HIP 65923 |
6.57 |
| 2026-02-17 12:00 |
13:31:08.53 |
+13:24:30.4 |
HIP 65923 |
5.25 |
| 2026-02-18 00:00 |
13:31:04.69 |
+13:25:27.5 |
HIP 65923 |
3.92 |
| 2026-02-18 12:00 |
13:31:00.78 |
+13:26:24.6 |
HIP 65923 |
2.58 |
| 2026-02-19 00:00 |
13:30:56.81 |
+13:27:21.8 |
HIP 65923 |
1.23 |
| 2026-02-19 12:00 |
13:30:52.78 |
+13:28:19.2 |
HIP 65923 |
0.27 |
| 2026-02-20 00:00 |
13:30:48.69 |
+13:29:16.5 |
HIP 65923 |
1.55 |
| 2026-02-20 12:00 |
13:30:44.54 |
+13:30:14.0 |
HIP 65923 |
2.93 |
| 2026-02-21 00:00 |
13:30:40.34 |
+13:31:11.5 |
HIP 65923 |
4.33 |
| 2026-02-21 12:00 |
13:30:36.07 |
+13:32:09.0 |
HIP 65923 |
5.74 |
| 2026-02-22 00:00 |
13:30:31.75 |
+13:33:06.6 |
HIP 65923 |
7.16 |
| 2026-02-22 12:00 |
13:30:27.37 |
+13:34:04.3 |
HIP 65923 |
8.59 |
| 2026-02-23 00:00 |
13:30:22.93 |
+13:35:01.9 |
HIP 65923 |
10.04 |
| 2026-02-23 12:00 |
13:30:18.44 |
+13:35:59.6 |
HIP 65923 |
11.49 |
| 2026-02-24 00:00 |
13:30:13.89 |
+13:36:57.3 |
HIP 65923 |
12.96 |