P/2019 A2 (ATLAS)
| Parameter |
Value |
| Designation |
P/2019 A2 (ATLAS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-11-21T10:46:12.993600Z |
| Orbit solution date (soln_date, UTC) |
2021-08-06T00:42:48Z |
| Obs used |
284 |
| NEO |
- |
| M1 |
11.700 |
| K1 |
8.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2019-01-04T11:38:04.992000Z |
| Discovery magnitude (MPC) |
18.70 c |
| Discovery observatory (MPC) |
T05 · ATLAS-HKO, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-02-09.0000000 |
| e |
0.38199370 |
| q (au) |
3.542902 |
| a (au) |
5.732793 |
| i (deg) |
14.855261 |
| Ω (om, deg) |
139.462645 |
| ω (w, deg) |
324.226252 |
| M (ma, deg) |
5.712176 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.764 + 3.368\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.764 |
| n |
3.368 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
4.853 |
| 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) |
| 2026-02-03 00:00 |
19:29:03.68 |
-14:54:04.4 |
HIP 95755 |
13.87 |
| 2026-02-03 12:00 |
19:29:20.45 |
-14:53:30.8 |
HIP 95755 |
16.67 |
| 2026-02-04 00:00 |
19:29:37.18 |
-14:52:57.1 |
HIP 95755 |
19.92 |
| 2026-02-04 12:00 |
19:29:53.87 |
-14:52:23.1 |
HIP 95755 |
23.43 |
| 2026-02-05 00:00 |
19:30:10.53 |
-14:51:48.9 |
HIP 95974 |
21.39 |
| 2026-02-05 12:00 |
19:30:27.14 |
-14:51:14.6 |
HIP 95974 |
19.00 |
| 2026-02-06 00:00 |
19:30:43.72 |
-14:50:40.0 |
HIP 95974 |
17.23 |
| 2026-02-06 12:00 |
19:31:00.26 |
-14:50:05.3 |
HIP 95974 |
16.30 |
| 2026-02-07 00:00 |
19:31:16.75 |
-14:49:30.4 |
HIP 95974 |
16.34 |
| 2026-02-07 12:00 |
19:31:33.20 |
-14:48:55.4 |
HIP 96105 |
13.93 |
| 2026-02-08 00:00 |
19:31:49.61 |
-14:48:20.1 |
HIP 96105 |
11.05 |
| 2026-02-08 12:00 |
19:32:05.98 |
-14:47:44.7 |
HIP 96105 |
9.08 |
| 2026-02-09 00:00 |
19:32:22.30 |
-14:47:09.1 |
HIP 96105 |
8.65 |
| 2026-02-09 12:00 |
19:32:38.58 |
-14:46:33.4 |
HIP 96105 |
9.95 |
| 2026-02-10 00:00 |
19:32:54.81 |
-14:45:57.5 |
HIP 96105 |
12.44 |
| 2026-02-10 12:00 |
19:33:11.00 |
-14:45:21.5 |
HIP 96169 |
15.14 |
| 2026-02-11 00:00 |
19:33:27.14 |
-14:44:45.2 |
HIP 96169 |
15.97 |
| 2026-02-11 12:00 |
19:33:43.23 |
-14:44:08.9 |
HIP 96169 |
17.66 |
| 2026-02-12 00:00 |
19:33:59.27 |
-14:43:32.4 |
HIP 96169 |
19.98 |
| 2026-02-12 12:00 |
19:34:15.27 |
-14:42:55.7 |
HIP 96169 |
22.75 |
| 2026-02-13 00:00 |
19:34:31.22 |
-14:42:18.9 |
HIP 96169 |
25.81 |
| 2026-02-13 12:00 |
19:34:47.11 |
-14:41:42.0 |
HIP 96169 |
29.06 |
| 2026-02-14 00:00 |
19:35:02.96 |
-14:41:04.9 |
HIP 96169 |
32.45 |
| 2026-02-14 12:00 |
19:35:18.75 |
-14:40:27.7 |
HIP 96506 |
30.84 |
| 2026-02-15 00:00 |
19:35:34.49 |
-14:39:50.3 |
HIP 96506 |
27.22 |
| 2026-02-15 12:00 |
19:35:50.18 |
-14:39:12.8 |
HIP 96506 |
23.68 |
| 2026-02-16 00:00 |
19:36:05.81 |
-14:38:35.3 |
HIP 96506 |
20.27 |
| 2026-02-16 12:00 |
19:36:21.39 |
-14:37:57.5 |
HIP 96506 |
17.04 |
| 2026-02-17 00:00 |
19:36:36.92 |
-14:37:19.7 |
HIP 96506 |
14.12 |
| 2026-02-17 12:00 |
19:36:52.38 |
-14:36:41.7 |
HIP 96506 |
11.72 |
| 2026-02-18 00:00 |
19:37:07.80 |
-14:36:03.7 |
HIP 96506 |
10.21 |
| 2026-02-18 12:00 |
19:37:23.15 |
-14:35:25.5 |
HIP 96506 |
9.99 |
| 2026-02-19 00:00 |
19:37:38.45 |
-14:34:47.2 |
HIP 96506 |
11.11 |
| 2026-02-19 12:00 |
19:37:53.68 |
-14:34:08.9 |
HIP 96557 |
11.86 |
| 2026-02-20 00:00 |
19:38:08.86 |
-14:33:30.4 |
HIP 96557 |
13.38 |
| 2026-02-20 12:00 |
19:38:23.98 |
-14:32:51.8 |
HIP 96557 |
15.66 |
| 2026-02-21 00:00 |
19:38:39.03 |
-14:32:13.2 |
HIP 96557 |
18.40 |
| 2026-02-21 12:00 |
19:38:54.03 |
-14:31:34.4 |
HIP 96557 |
21.42 |
| 2026-02-22 00:00 |
19:39:08.96 |
-14:30:55.6 |
HIP 96738 |
22.80 |
| 2026-02-22 12:00 |
19:39:23.83 |
-14:30:16.7 |
HIP 96738 |
21.93 |
| 2026-02-23 00:00 |
19:39:38.64 |
-14:29:37.7 |
HIP 96738 |
21.65 |
| 2026-02-23 12:00 |
19:39:53.38 |
-14:28:58.7 |
HIP 96738 |
21.98 |
| 2026-02-24 00:00 |
19:40:08.06 |
-14:28:19.6 |
HIP 96738 |
22.89 |