| 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) |
| 2026-07-29 00:00 |
23:41:56.76 |
-55:55:20.5 |
HIP 116935 |
27.51 |
| 2026-07-29 12:00 |
23:41:50.50 |
-55:56:40.3 |
HIP 116935 |
26.26 |
| 2026-07-30 00:00 |
23:41:44.16 |
-55:57:59.7 |
HIP 116935 |
25.06 |
| 2026-07-30 12:00 |
23:41:37.76 |
-55:59:18.8 |
HIP 116935 |
23.90 |
| 2026-07-31 00:00 |
23:41:31.28 |
-56:00:37.6 |
HIP 116935 |
22.81 |
| 2026-07-31 12:00 |
23:41:24.74 |
-56:01:56.1 |
HIP 116935 |
21.79 |
| 2026-08-01 00:00 |
23:41:18.12 |
-56:03:14.2 |
HIP 116935 |
20.84 |
| 2026-08-01 12:00 |
23:41:11.44 |
-56:04:32.0 |
HIP 116935 |
19.99 |
| 2026-08-02 00:00 |
23:41:04.68 |
-56:05:49.5 |
HIP 116935 |
19.24 |
| 2026-08-02 12:00 |
23:40:57.86 |
-56:07:06.7 |
HIP 116835 |
18.15 |
| 2026-08-03 00:00 |
23:40:50.97 |
-56:08:23.5 |
HIP 116835 |
16.84 |
| 2026-08-03 12:00 |
23:40:44.02 |
-56:09:39.9 |
HIP 116835 |
15.60 |
| 2026-08-04 00:00 |
23:40:37.00 |
-56:10:56.0 |
HIP 116835 |
14.43 |
| 2026-08-04 12:00 |
23:40:29.91 |
-56:12:11.7 |
HIP 116835 |
13.36 |
| 2026-08-05 00:00 |
23:40:22.75 |
-56:13:27.0 |
HIP 116835 |
12.41 |
| 2026-08-05 12:00 |
23:40:15.53 |
-56:14:42.0 |
HIP 116835 |
11.61 |
| 2026-08-06 00:00 |
23:40:08.25 |
-56:15:56.6 |
HIP 116835 |
11.01 |
| 2026-08-06 12:00 |
23:40:00.90 |
-56:17:10.7 |
HIP 116835 |
10.62 |
| 2026-08-07 00:00 |
23:39:53.49 |
-56:18:24.5 |
HIP 116835 |
10.47 |
| 2026-08-07 12:00 |
23:39:46.01 |
-56:19:37.9 |
HIP 116835 |
10.58 |
| 2026-08-08 00:00 |
23:39:38.47 |
-56:20:50.9 |
HIP 116835 |
10.94 |
| 2026-08-08 12:00 |
23:39:30.87 |
-56:22:03.4 |
HIP 116835 |
11.51 |
| 2026-08-09 00:00 |
23:39:23.21 |
-56:23:15.6 |
HIP 116640 |
10.49 |
| 2026-08-09 12:00 |
23:39:15.48 |
-56:24:27.3 |
HIP 116640 |
9.09 |
| 2026-08-10 00:00 |
23:39:07.70 |
-56:25:38.6 |
HIP 116640 |
7.76 |
| 2026-08-10 12:00 |
23:38:59.86 |
-56:26:49.4 |
HIP 116640 |
6.54 |
| 2026-08-11 00:00 |
23:38:51.95 |
-56:27:59.8 |
HIP 116640 |
5.52 |
| 2026-08-11 12:00 |
23:38:43.99 |
-56:29:09.7 |
HIP 116640 |
4.82 |
| 2026-08-12 00:00 |
23:38:35.97 |
-56:30:19.2 |
HIP 116640 |
4.59 |
| 2026-08-12 12:00 |
23:38:27.90 |
-56:31:28.2 |
HIP 116640 |
4.89 |
| 2026-08-13 00:00 |
23:38:19.76 |
-56:32:36.8 |
HIP 116640 |
5.63 |
| 2026-08-13 12:00 |
23:38:11.57 |
-56:33:44.8 |
HIP 116640 |
6.68 |
| 2026-08-14 00:00 |
23:38:03.33 |
-56:34:52.4 |
HIP 116640 |
7.91 |
| 2026-08-14 12:00 |
23:37:55.03 |
-56:35:59.5 |
HIP 116640 |
9.24 |
| 2026-08-15 00:00 |
23:37:46.68 |
-56:37:06.1 |
HIP 116640 |
10.65 |
| 2026-08-15 12:00 |
23:37:38.28 |
-56:38:12.2 |
HIP 116640 |
12.09 |
| 2026-08-16 00:00 |
23:37:29.83 |
-56:39:17.8 |
HIP 116640 |
13.57 |
| 2026-08-16 12:00 |
23:37:21.32 |
-56:40:22.9 |
HIP 116640 |
15.07 |
| 2026-08-17 00:00 |
23:37:12.76 |
-56:41:27.5 |
HIP 116640 |
16.58 |
| 2026-08-17 12:00 |
23:37:04.16 |
-56:42:31.6 |
HIP 116640 |
18.10 |
| 2026-08-18 00:00 |
23:36:55.50 |
-56:43:35.1 |
HIP 116387 |
16.62 |
| 2026-08-18 12:00 |
23:36:46.80 |
-56:44:38.1 |
HIP 116387 |
15.14 |
| 2026-08-19 00:00 |
23:36:38.05 |
-56:45:40.6 |
HIP 116387 |
13.68 |