| Parameter |
Value |
| Designation |
P/2019 A1 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-10-11T01:01:39.613440Z |
| Orbit solution date (soln_date, UTC) |
2021-05-31T22:43:01Z |
| Obs used |
63 |
| NEO |
- |
| M1 |
17.300 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-01-03T15:02:41.568000Z |
| Discovery magnitude (MPC) |
20.50 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-01-18.0000000 |
| e |
0.56892834 |
| q (au) |
2.211667 |
| a (au) |
5.130625 |
| i (deg) |
13.743622 |
| Ω (om, deg) |
312.299496 |
| ω (w, deg) |
150.846750 |
| M (ma, deg) |
8.392589 |
Magnitude
Scatter + Global Linear
$$
M_a = (19.446 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
19.446 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-0.718 |
| k |
0.800 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
20:11:58.46 |
-21:22:05.9 |
HIP 99535 |
4.16 |
| 2026-09-20 12:00 |
20:11:52.45 |
-21:22:02.4 |
HIP 99535 |
4.63 |
| 2026-09-21 00:00 |
20:11:46.59 |
-21:21:58.5 |
HIP 99535 |
5.40 |
| 2026-09-21 12:00 |
20:11:40.87 |
-21:21:54.2 |
HIP 99535 |
6.34 |
| 2026-09-22 00:00 |
20:11:35.30 |
-21:21:49.4 |
HIP 99535 |
7.37 |
| 2026-09-22 12:00 |
20:11:29.88 |
-21:21:44.2 |
HIP 99535 |
8.44 |
| 2026-09-23 00:00 |
20:11:24.60 |
-21:21:38.5 |
HIP 99535 |
9.53 |
| 2026-09-23 12:00 |
20:11:19.46 |
-21:21:32.3 |
HIP 99535 |
10.61 |
| 2026-09-24 00:00 |
20:11:14.47 |
-21:21:25.7 |
HIP 99535 |
11.68 |
| 2026-09-24 12:00 |
20:11:09.63 |
-21:21:18.7 |
HIP 99535 |
12.74 |
| 2026-09-25 00:00 |
20:11:04.94 |
-21:21:11.2 |
HIP 99535 |
13.77 |
| 2026-09-25 12:00 |
20:11:00.39 |
-21:21:03.3 |
HIP 99535 |
14.77 |
| 2026-09-26 00:00 |
20:10:55.99 |
-21:20:55.0 |
HIP 99535 |
15.75 |
| 2026-09-26 12:00 |
20:10:51.74 |
-21:20:46.1 |
HIP 99535 |
16.70 |
| 2026-09-27 00:00 |
20:10:47.63 |
-21:20:36.9 |
HIP 99535 |
17.62 |
| 2026-09-27 12:00 |
20:10:43.68 |
-21:20:27.2 |
HIP 99535 |
18.51 |
| 2026-09-28 00:00 |
20:10:39.87 |
-21:20:17.1 |
HIP 99535 |
19.37 |
| 2026-09-28 12:00 |
20:10:36.21 |
-21:20:06.5 |
HIP 99535 |
20.20 |
| 2026-09-29 00:00 |
20:10:32.70 |
-21:19:55.5 |
HIP 99535 |
21.00 |
| 2026-09-29 12:00 |
20:10:29.34 |
-21:19:44.0 |
HIP 99535 |
21.76 |
| 2026-09-30 00:00 |
20:10:26.13 |
-21:19:32.1 |
HIP 99535 |
22.49 |
| 2026-09-30 12:00 |
20:10:23.06 |
-21:19:19.8 |
HIP 99535 |
23.19 |
| 2026-10-01 00:00 |
20:10:20.15 |
-21:19:07.0 |
HIP 99535 |
23.86 |
| 2026-10-01 12:00 |
20:10:17.39 |
-21:18:53.8 |
HIP 99535 |
24.49 |
| 2026-10-02 00:00 |
20:10:14.78 |
-21:18:40.2 |
HIP 99535 |
25.10 |
| 2026-10-02 12:00 |
20:10:12.32 |
-21:18:26.1 |
HIP 99535 |
25.66 |
| 2026-10-03 00:00 |
20:10:10.01 |
-21:18:11.6 |
HIP 99535 |
26.20 |
| 2026-10-03 12:00 |
20:10:07.85 |
-21:17:56.6 |
HIP 99535 |
26.70 |
| 2026-10-04 00:00 |
20:10:05.84 |
-21:17:41.2 |
HIP 99535 |
27.17 |
| 2026-10-04 12:00 |
20:10:03.98 |
-21:17:25.4 |
HIP 99535 |
27.61 |
| 2026-10-05 00:00 |
20:10:02.27 |
-21:17:09.1 |
HIP 99535 |
28.02 |
| 2026-10-05 12:00 |
20:10:00.72 |
-21:16:52.4 |
HIP 99535 |
28.39 |
| 2026-10-06 00:00 |
20:09:59.32 |
-21:16:35.3 |
HIP 99535 |
28.73 |
| 2026-10-06 12:00 |
20:09:58.06 |
-21:16:17.7 |
HIP 99535 |
29.04 |
| 2026-10-07 00:00 |
20:09:56.97 |
-21:15:59.7 |
HIP 99535 |
29.31 |
| 2026-10-07 12:00 |
20:09:56.02 |
-21:15:41.3 |
HIP 99535 |
29.56 |
| 2026-10-08 00:00 |
20:09:55.22 |
-21:15:22.4 |
HIP 99535 |
29.77 |
| 2026-10-08 12:00 |
20:09:54.58 |
-21:15:03.1 |
HIP 99535 |
29.95 |
| 2026-10-09 00:00 |
20:09:54.09 |
-21:14:43.4 |
HIP 99535 |
30.10 |
| 2026-10-09 12:00 |
20:09:53.75 |
-21:14:23.2 |
HIP 99535 |
30.22 |
| 2026-10-10 00:00 |
20:09:53.56 |
-21:14:02.6 |
HIP 99535 |
30.30 |
| 2026-10-10 12:00 |
20:09:53.53 |
-21:13:41.5 |
HIP 99535 |
30.36 |
| 2026-10-11 00:00 |
20:09:53.64 |
-21:13:20.1 |
HIP 99535 |
30.39 |