| Parameter |
Value |
| Designation |
C/2019 M3 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-01-03T01:14:33.895680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:57Z |
| Obs used |
340 |
| NEO |
- |
| M1 |
13.800 |
| K1 |
6.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2019-06-30T12:24:39.600000Z |
| Discovery magnitude (MPC) |
19.39 c |
| Discovery observatory (MPC) |
T05 · ATLAS-HKO, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-08-04.0000000 |
| e |
1.00221470 |
| q (au) |
2.417809 |
| a (au) |
-1091.709033 |
| i (deg) |
99.436295 |
| Ω (om, deg) |
154.896272 |
| ω (w, deg) |
87.935053 |
| M (ma, deg) |
0.005819 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.222 + 2.205\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.222 |
| n |
2.205 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
| 2019-06-30 |
2019-09-05 |
+4.9840 |
-2.533 |
| 2019-09-05 |
2020-11-22 |
-48.4696 |
+27.440 |
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 |
23:26:18.71 |
-57:30:59.6 |
HIP 115578 |
12.82 |
| 2026-09-20 12:00 |
23:26:08.76 |
-57:31:20.1 |
HIP 115578 |
11.51 |
| 2026-09-21 00:00 |
23:25:58.83 |
-57:31:39.8 |
HIP 115578 |
10.22 |
| 2026-09-21 12:00 |
23:25:48.92 |
-57:31:58.9 |
HIP 115578 |
8.96 |
| 2026-09-22 00:00 |
23:25:39.02 |
-57:32:17.2 |
HIP 115578 |
7.72 |
| 2026-09-22 12:00 |
23:25:29.13 |
-57:32:34.8 |
HIP 115578 |
6.54 |
| 2026-09-23 00:00 |
23:25:19.27 |
-57:32:51.7 |
HIP 115578 |
5.44 |
| 2026-09-23 12:00 |
23:25:09.42 |
-57:33:07.9 |
HIP 115578 |
4.47 |
| 2026-09-24 00:00 |
23:24:59.59 |
-57:33:23.4 |
HIP 115578 |
3.74 |
| 2026-09-24 12:00 |
23:24:49.78 |
-57:33:38.1 |
HIP 115578 |
3.40 |
| 2026-09-25 00:00 |
23:24:39.99 |
-57:33:52.2 |
HIP 115578 |
3.55 |
| 2026-09-25 12:00 |
23:24:30.23 |
-57:34:05.5 |
HIP 115578 |
4.13 |
| 2026-09-26 00:00 |
23:24:20.48 |
-57:34:18.1 |
HIP 115578 |
5.00 |
| 2026-09-26 12:00 |
23:24:10.76 |
-57:34:30.1 |
HIP 115578 |
6.03 |
| 2026-09-27 00:00 |
23:24:01.07 |
-57:34:41.3 |
HIP 115578 |
7.14 |
| 2026-09-27 12:00 |
23:23:51.40 |
-57:34:51.8 |
HIP 115429 |
8.08 |
| 2026-09-28 00:00 |
23:23:41.75 |
-57:35:01.6 |
HIP 115429 |
6.81 |
| 2026-09-28 12:00 |
23:23:32.14 |
-57:35:10.7 |
HIP 115429 |
5.56 |
| 2026-09-29 00:00 |
23:23:22.55 |
-57:35:19.1 |
HIP 115429 |
4.35 |
| 2026-09-29 12:00 |
23:23:12.99 |
-57:35:26.7 |
HIP 115429 |
3.23 |
| 2026-09-30 00:00 |
23:23:03.46 |
-57:35:33.7 |
HIP 115429 |
2.28 |
| 2026-09-30 12:00 |
23:22:53.96 |
-57:35:40.0 |
HIP 115429 |
1.83 |
| 2026-10-01 00:00 |
23:22:44.50 |
-57:35:45.6 |
HIP 115429 |
2.19 |
| 2026-10-01 12:00 |
23:22:35.06 |
-57:35:50.4 |
HIP 115429 |
3.08 |
| 2026-10-02 00:00 |
23:22:25.66 |
-57:35:54.6 |
HIP 115429 |
4.16 |
| 2026-10-02 12:00 |
23:22:16.29 |
-57:35:58.0 |
HIP 115429 |
5.33 |
| 2026-10-03 00:00 |
23:22:06.96 |
-57:36:00.8 |
HIP 115429 |
6.52 |
| 2026-10-03 12:00 |
23:21:57.67 |
-57:36:02.9 |
HIP 115429 |
7.74 |
| 2026-10-04 00:00 |
23:21:48.41 |
-57:36:04.2 |
HIP 115429 |
8.95 |
| 2026-10-04 12:00 |
23:21:39.19 |
-57:36:04.9 |
HIP 115429 |
10.17 |
| 2026-10-05 00:00 |
23:21:30.01 |
-57:36:04.9 |
HIP 115429 |
11.39 |
| 2026-10-05 12:00 |
23:21:20.87 |
-57:36:04.1 |
HIP 115429 |
12.61 |
| 2026-10-06 00:00 |
23:21:11.77 |
-57:36:02.7 |
HIP 115429 |
13.82 |
| 2026-10-06 12:00 |
23:21:02.71 |
-57:36:00.6 |
HIP 115429 |
15.03 |
| 2026-10-07 00:00 |
23:20:53.69 |
-57:35:57.8 |
HIP 115429 |
16.24 |
| 2026-10-07 12:00 |
23:20:44.72 |
-57:35:54.3 |
HIP 115429 |
17.44 |
| 2026-10-08 00:00 |
23:20:35.79 |
-57:35:50.1 |
HIP 115429 |
18.64 |
| 2026-10-08 12:00 |
23:20:26.90 |
-57:35:45.2 |
HIP 115429 |
19.83 |
| 2026-10-09 00:00 |
23:20:18.07 |
-57:35:39.6 |
HIP 115429 |
21.02 |
| 2026-10-09 12:00 |
23:20:09.28 |
-57:35:33.4 |
HIP 115429 |
22.20 |
| 2026-10-10 00:00 |
23:20:00.53 |
-57:35:26.4 |
HIP 115429 |
23.38 |
| 2026-10-10 12:00 |
23:19:51.84 |
-57:35:18.8 |
HIP 115429 |
24.55 |
| 2026-10-11 00:00 |
23:19:43.20 |
-57:35:10.6 |
HIP 115429 |
25.71 |