| 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) |
| 2026-03-26 00:00 |
23:58:10.38 |
-08:47:13.3 |
HIP 118219 |
9.65 |
| 2026-03-26 12:00 |
23:58:59.59 |
-08:42:43.7 |
HIP 118219 |
7.29 |
| 2026-03-27 00:00 |
23:59:48.79 |
-08:38:14.2 |
HIP 118253 |
13.52 |
| 2026-03-27 12:00 |
00:00:37.99 |
-08:33:45.0 |
HIP 118253 |
22.72 |
| 2026-03-28 00:00 |
00:01:27.17 |
-08:29:15.8 |
HIP 210 |
17.74 |
| 2026-03-28 12:00 |
00:02:16.35 |
-08:24:46.9 |
HIP 210 |
7.17 |
| 2026-03-29 00:00 |
00:03:05.52 |
-08:20:18.1 |
HIP 210 |
11.13 |
| 2026-03-29 12:00 |
00:03:54.68 |
-08:15:49.6 |
HIP 373 |
12.13 |
| 2026-03-30 00:00 |
00:04:43.83 |
-08:11:21.2 |
HIP 373 |
1.02 |
| 2026-03-30 12:00 |
00:05:32.98 |
-08:06:53.0 |
HIP 373 |
13.81 |
| 2026-03-31 00:00 |
00:06:22.11 |
-08:02:25.1 |
HIP 629 |
20.61 |
| 2026-03-31 12:00 |
00:07:11.24 |
-07:57:57.3 |
HIP 629 |
7.65 |
| 2026-04-01 00:00 |
00:08:00.36 |
-07:53:29.8 |
HIP 629 |
5.30 |
| 2026-04-01 12:00 |
00:08:49.47 |
-07:49:02.5 |
HIP 711 |
4.78 |
| 2026-04-02 00:00 |
00:09:38.57 |
-07:44:35.4 |
HIP 711 |
15.34 |
| 2026-04-02 12:00 |
00:10:27.67 |
-07:40:08.5 |
HIP 904 |
20.34 |
| 2026-04-03 00:00 |
00:11:16.75 |
-07:35:41.9 |
HIP 904 |
13.26 |
| 2026-04-03 12:00 |
00:12:05.83 |
-07:31:15.5 |
HIP 977 |
10.86 |
| 2026-04-04 00:00 |
00:12:54.90 |
-07:26:49.4 |
HIP 1053 |
14.51 |
| 2026-04-04 12:00 |
00:13:43.96 |
-07:22:23.6 |
HIP 1134 |
12.31 |
| 2026-04-05 00:00 |
00:14:33.02 |
-07:17:58.0 |
HIP 1134 |
8.27 |
| 2026-04-05 12:00 |
00:15:22.06 |
-07:13:32.7 |
HIP 1252 |
6.94 |
| 2026-04-06 00:00 |
00:16:11.10 |
-07:09:07.7 |
HIP 1303 |
7.79 |
| 2026-04-06 12:00 |
00:17:00.12 |
-07:04:42.9 |
HIP 1350 |
6.98 |
| 2026-04-07 00:00 |
00:17:49.14 |
-07:00:18.5 |
HIP 1350 |
17.73 |
| 2026-04-07 12:00 |
00:18:38.16 |
-06:55:54.3 |
HIP 1573 |
22.72 |
| 2026-04-08 00:00 |
00:19:27.16 |
-06:51:30.5 |
HIP 1573 |
22.03 |
| 2026-04-08 12:00 |
00:20:16.15 |
-06:47:06.9 |
HIP 1573 |
28.09 |
| 2026-04-09 00:00 |
00:21:05.14 |
-06:42:43.7 |
HIP 1778 |
22.63 |
| 2026-04-09 12:00 |
00:21:54.11 |
-06:38:20.8 |
HIP 1778 |
10.09 |
| 2026-04-10 00:00 |
00:22:43.08 |
-06:33:58.3 |
HIP 1778 |
5.06 |
| 2026-04-10 12:00 |
00:23:32.04 |
-06:29:36.1 |
HIP 1812 |
8.16 |
| 2026-04-11 00:00 |
00:24:20.98 |
-06:25:14.2 |
HIP 1815 |
20.13 |
| 2026-04-11 12:00 |
00:25:09.92 |
-06:20:52.7 |
HIP 2044 |
20.37 |
| 2026-04-12 00:00 |
00:25:58.85 |
-06:16:31.6 |
HIP 2044 |
12.48 |
| 2026-04-12 12:00 |
00:26:47.77 |
-06:12:10.8 |
HIP 2044 |
15.18 |
| 2026-04-13 00:00 |
00:27:36.68 |
-06:07:50.4 |
HIP 2201 |
21.44 |
| 2026-04-13 12:00 |
00:28:25.58 |
-06:03:30.4 |
HIP 2292 |
15.42 |
| 2026-04-14 00:00 |
00:29:14.47 |
-05:59:10.8 |
HIP 2292 |
4.60 |
| 2026-04-14 12:00 |
00:30:03.35 |
-05:54:51.6 |
HIP 2350 |
9.09 |
| 2026-04-15 00:00 |
00:30:52.22 |
-05:50:32.8 |
HIP 2350 |
13.84 |
| 2026-04-15 12:00 |
00:31:41.07 |
-05:46:14.5 |
HIP 2350 |
25.16 |
| 2026-04-16 00:00 |
00:32:29.92 |
-05:41:56.6 |
HIP 2699 |
26.45 |