P/2019 A4 (PANSTARRS)
| Parameter |
Value |
| Designation |
P/2019 A4 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-12-05T05:23:53.433600Z |
| Orbit solution date (soln_date, UTC) |
2022-06-07T21:45:21Z |
| Obs used |
85 |
| NEO |
- |
| M1 |
15.500 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-01-10T08:46:05.376000Z |
| Discovery magnitude (MPC) |
20.60 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-01-18.0000000 |
| e |
0.08960737 |
| q (au) |
2.379288 |
| a (au) |
2.613474 |
| i (deg) |
13.318898 |
| Ω (om, deg) |
119.300120 |
| ω (w, deg) |
341.836468 |
| M (ma, deg) |
10.211830 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.420 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.420 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.849 |
| k |
0.999 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
22:34:22.69 |
-16:18:01.3 |
HIP 111472 |
13.95 |
| 2026-02-03 12:00 |
22:35:11.69 |
-16:13:52.1 |
HIP 111472 |
13.90 |
| 2026-02-04 00:00 |
22:36:00.70 |
-16:09:42.5 |
HIP 111563 |
13.64 |
| 2026-02-04 12:00 |
22:36:49.72 |
-16:05:32.3 |
HIP 111691 |
19.52 |
| 2026-02-05 00:00 |
22:37:38.76 |
-16:01:21.6 |
HIP 111642 |
20.35 |
| 2026-02-05 12:00 |
22:38:27.81 |
-15:57:10.4 |
HIP 111911 |
24.11 |
| 2026-02-06 00:00 |
22:39:16.88 |
-15:52:58.6 |
HIP 111911 |
13.13 |
| 2026-02-06 12:00 |
22:40:05.96 |
-15:48:46.4 |
HIP 111911 |
8.76 |
| 2026-02-07 00:00 |
22:40:55.06 |
-15:44:33.6 |
HIP 111911 |
17.19 |
| 2026-02-07 12:00 |
22:41:44.17 |
-15:40:20.4 |
HIP 112192 |
27.19 |
| 2026-02-08 00:00 |
22:42:33.29 |
-15:36:06.6 |
HIP 112192 |
21.27 |
| 2026-02-08 12:00 |
22:43:22.43 |
-15:31:52.4 |
HIP 112192 |
21.94 |
| 2026-02-09 00:00 |
22:44:11.57 |
-15:27:37.7 |
HIP 112356 |
19.83 |
| 2026-02-09 12:00 |
22:45:00.73 |
-15:23:22.5 |
HIP 112356 |
13.35 |
| 2026-02-10 00:00 |
22:45:49.91 |
-15:19:06.9 |
HIP 112356 |
16.74 |
| 2026-02-10 12:00 |
22:46:39.09 |
-15:14:50.8 |
HIP 112526 |
14.59 |
| 2026-02-11 00:00 |
22:47:28.29 |
-15:10:34.2 |
HIP 112526 |
2.80 |
| 2026-02-11 12:00 |
22:48:17.49 |
-15:06:17.2 |
HIP 112526 |
11.01 |
| 2026-02-12 00:00 |
22:49:06.71 |
-15:01:59.7 |
HIP 112526 |
23.53 |
| 2026-02-12 12:00 |
22:49:55.94 |
-14:57:41.9 |
HIP 112797 |
16.52 |
| 2026-02-13 00:00 |
22:50:45.18 |
-14:53:23.5 |
HIP 112797 |
9.91 |
| 2026-02-13 12:00 |
22:51:34.42 |
-14:49:04.8 |
HIP 112797 |
15.62 |
| 2026-02-14 00:00 |
22:52:23.68 |
-14:44:45.7 |
HIP 112920 |
19.33 |
| 2026-02-14 12:00 |
22:53:12.95 |
-14:40:26.1 |
HIP 112920 |
21.80 |
| 2026-02-15 00:00 |
22:54:02.22 |
-14:36:06.2 |
HIP 113020 |
23.23 |
| 2026-02-15 12:00 |
22:54:51.51 |
-14:31:45.8 |
HIP 113020 |
28.11 |
| 2026-02-16 00:00 |
22:55:40.80 |
-14:27:25.1 |
HIP 113378 |
29.67 |
| 2026-02-16 12:00 |
22:56:30.10 |
-14:23:04.0 |
HIP 113378 |
18.14 |
| 2026-02-17 00:00 |
22:57:19.40 |
-14:18:42.5 |
HIP 113395 |
8.62 |
| 2026-02-17 12:00 |
22:58:08.71 |
-14:14:20.7 |
HIP 113395 |
4.64 |
| 2026-02-18 00:00 |
22:58:58.03 |
-14:09:58.5 |
HIP 113395 |
17.11 |
| 2026-02-18 12:00 |
22:59:47.36 |
-14:05:35.9 |
HIP 113631 |
17.69 |
| 2026-02-19 00:00 |
23:00:36.69 |
-14:01:13.1 |
HIP 113631 |
14.54 |
| 2026-02-19 12:00 |
23:01:26.03 |
-13:56:49.9 |
HIP 113675 |
19.48 |
| 2026-02-20 00:00 |
23:02:15.37 |
-13:52:26.3 |
HIP 113798 |
23.81 |
| 2026-02-20 12:00 |
23:03:04.71 |
-13:48:02.5 |
HIP 113798 |
27.63 |
| 2026-02-21 00:00 |
23:03:54.06 |
-13:43:38.4 |
HIP 113810 |
27.77 |
| 2026-02-21 12:00 |
23:04:43.41 |
-13:39:13.9 |
HIP 114094 |
26.62 |
| 2026-02-22 00:00 |
23:05:32.77 |
-13:34:49.2 |
HIP 114094 |
17.36 |
| 2026-02-22 12:00 |
23:06:22.13 |
-13:30:24.2 |
HIP 114094 |
14.85 |
| 2026-02-23 00:00 |
23:07:11.49 |
-13:25:58.9 |
HIP 114094 |
21.60 |
| 2026-02-23 12:00 |
23:08:00.85 |
-13:21:33.3 |
HIP 114311 |
26.10 |
| 2026-02-24 00:00 |
23:08:50.22 |
-13:17:07.5 |
HIP 114426 |
23.20 |