| Parameter |
Value |
| Designation |
C/2019 J3 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-08-01T21:21:25.338240Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:54Z |
| Obs used |
270 |
| NEO |
- |
| M1 |
15.300 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-05-14T13:01:15.024000Z |
| Discovery magnitude (MPC) |
18.73 o |
| Discovery observatory (MPC) |
T05 · ATLAS-HKO, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-07-10.0000000 |
| e |
1.00067795 |
| q (au) |
2.373522 |
| a (au) |
-3501.039615 |
| i (deg) |
131.414908 |
| Ω (om, deg) |
270.517035 |
| ω (w, deg) |
16.552399 |
| M (ma, deg) |
-0.000109 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.286 + 2.429\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.286 |
| n |
2.429 |
| gf |
0.944 |
| gb |
-0.898 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
07:44:06.25 |
+39:47:41.9 |
HIP 37789 |
17.16 |
| 2026-09-20 12:00 |
07:44:08.86 |
+39:47:55.8 |
HIP 37789 |
17.08 |
| 2026-09-21 00:00 |
07:44:11.41 |
+39:48:10.0 |
HIP 37789 |
17.02 |
| 2026-09-21 12:00 |
07:44:13.90 |
+39:48:24.3 |
HIP 37789 |
17.00 |
| 2026-09-22 00:00 |
07:44:16.33 |
+39:48:39.0 |
HIP 37789 |
16.99 |
| 2026-09-22 12:00 |
07:44:18.70 |
+39:48:53.8 |
HIP 37789 |
17.02 |
| 2026-09-23 00:00 |
07:44:21.01 |
+39:49:08.9 |
HIP 37789 |
17.06 |
| 2026-09-23 12:00 |
07:44:23.26 |
+39:49:24.2 |
HIP 37789 |
17.13 |
| 2026-09-24 00:00 |
07:44:25.45 |
+39:49:39.7 |
HIP 37789 |
17.23 |
| 2026-09-24 12:00 |
07:44:27.58 |
+39:49:55.5 |
HIP 37789 |
17.34 |
| 2026-09-25 00:00 |
07:44:29.65 |
+39:50:11.5 |
HIP 37789 |
17.47 |
| 2026-09-25 12:00 |
07:44:31.65 |
+39:50:27.7 |
HIP 37789 |
17.62 |
| 2026-09-26 00:00 |
07:44:33.60 |
+39:50:44.1 |
HIP 37789 |
17.79 |
| 2026-09-26 12:00 |
07:44:35.48 |
+39:51:00.8 |
HIP 37789 |
17.98 |
| 2026-09-27 00:00 |
07:44:37.31 |
+39:51:17.7 |
HIP 37789 |
18.18 |
| 2026-09-27 12:00 |
07:44:39.07 |
+39:51:34.8 |
HIP 37789 |
18.39 |
| 2026-09-28 00:00 |
07:44:40.77 |
+39:51:52.1 |
HIP 37789 |
18.62 |
| 2026-09-28 12:00 |
07:44:42.40 |
+39:52:09.6 |
HIP 37789 |
18.86 |
| 2026-09-29 00:00 |
07:44:43.98 |
+39:52:27.3 |
HIP 37789 |
19.12 |
| 2026-09-29 12:00 |
07:44:45.48 |
+39:52:45.3 |
HIP 37789 |
19.38 |
| 2026-09-30 00:00 |
07:44:46.93 |
+39:53:03.5 |
HIP 37789 |
19.66 |
| 2026-09-30 12:00 |
07:44:48.31 |
+39:53:21.9 |
HIP 37789 |
19.94 |
| 2026-10-01 00:00 |
07:44:49.63 |
+39:53:40.5 |
HIP 37789 |
20.23 |
| 2026-10-01 12:00 |
07:44:50.89 |
+39:53:59.3 |
HIP 37789 |
20.53 |
| 2026-10-02 00:00 |
07:44:52.08 |
+39:54:18.3 |
HIP 37789 |
20.84 |
| 2026-10-02 12:00 |
07:44:53.20 |
+39:54:37.6 |
HIP 37789 |
21.15 |
| 2026-10-03 00:00 |
07:44:54.26 |
+39:54:57.0 |
HIP 37789 |
21.47 |
| 2026-10-03 12:00 |
07:44:55.26 |
+39:55:16.7 |
HIP 37789 |
21.80 |
| 2026-10-04 00:00 |
07:44:56.18 |
+39:55:36.5 |
HIP 37789 |
22.13 |
| 2026-10-04 12:00 |
07:44:57.05 |
+39:55:56.6 |
HIP 37789 |
22.46 |
| 2026-10-05 00:00 |
07:44:57.84 |
+39:56:16.8 |
HIP 37789 |
22.80 |
| 2026-10-05 12:00 |
07:44:58.57 |
+39:56:37.3 |
HIP 37789 |
23.14 |
| 2026-10-06 00:00 |
07:44:59.24 |
+39:56:57.9 |
HIP 37789 |
23.49 |
| 2026-10-06 12:00 |
07:44:59.83 |
+39:57:18.8 |
HIP 37789 |
23.84 |
| 2026-10-07 00:00 |
07:45:00.36 |
+39:57:39.9 |
HIP 37789 |
24.20 |
| 2026-10-07 12:00 |
07:45:00.82 |
+39:58:01.1 |
HIP 37789 |
24.55 |
| 2026-10-08 00:00 |
07:45:01.22 |
+39:58:22.6 |
HIP 37789 |
24.91 |
| 2026-10-08 12:00 |
07:45:01.54 |
+39:58:44.2 |
HIP 37789 |
25.28 |
| 2026-10-09 00:00 |
07:45:01.80 |
+39:59:06.0 |
HIP 37789 |
25.64 |
| 2026-10-09 12:00 |
07:45:01.99 |
+39:59:28.0 |
HIP 37789 |
26.01 |
| 2026-10-10 00:00 |
07:45:02.11 |
+39:59:50.2 |
HIP 37789 |
26.38 |
| 2026-10-10 12:00 |
07:45:02.16 |
+40:00:12.6 |
HIP 37789 |
26.75 |
| 2026-10-11 00:00 |
07:45:02.14 |
+40:00:35.2 |
HIP 37795 |
26.54 |