| 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) |
| 2026-09-25 00:00 |
03:54:46.40 |
+01:33:47.8 |
HIP 18261 |
19.03 |
| 2026-09-25 12:00 |
03:54:51.03 |
+01:31:13.6 |
HIP 18261 |
17.06 |
| 2026-09-26 00:00 |
03:54:55.25 |
+01:28:38.4 |
HIP 18261 |
15.28 |
| 2026-09-26 12:00 |
03:54:59.06 |
+01:26:02.4 |
HIP 18261 |
13.77 |
| 2026-09-27 00:00 |
03:55:02.46 |
+01:23:25.5 |
HIP 18261 |
12.59 |
| 2026-09-27 12:00 |
03:55:05.44 |
+01:20:47.9 |
HIP 18261 |
11.85 |
| 2026-09-28 00:00 |
03:55:08.00 |
+01:18:09.4 |
HIP 18261 |
11.60 |
| 2026-09-28 12:00 |
03:55:10.15 |
+01:15:30.2 |
HIP 18261 |
11.88 |
| 2026-09-29 00:00 |
03:55:11.88 |
+01:12:50.2 |
HIP 18261 |
12.64 |
| 2026-09-29 12:00 |
03:55:13.19 |
+01:10:09.5 |
HIP 18261 |
13.81 |
| 2026-09-30 00:00 |
03:55:14.08 |
+01:07:28.1 |
HIP 18261 |
15.28 |
| 2026-09-30 12:00 |
03:55:14.54 |
+01:04:46.1 |
HIP 18261 |
16.98 |
| 2026-10-01 00:00 |
03:55:14.58 |
+01:02:03.4 |
HIP 18239 |
17.53 |
| 2026-10-01 12:00 |
03:55:14.19 |
+00:59:20.1 |
HIP 18239 |
17.33 |
| 2026-10-02 00:00 |
03:55:13.37 |
+00:56:36.3 |
HIP 18239 |
17.44 |
| 2026-10-02 12:00 |
03:55:12.12 |
+00:53:51.9 |
HIP 18239 |
17.88 |
| 2026-10-03 00:00 |
03:55:10.44 |
+00:51:07.1 |
HIP 18408 |
16.77 |
| 2026-10-03 12:00 |
03:55:08.34 |
+00:48:21.8 |
HIP 18408 |
16.06 |
| 2026-10-04 00:00 |
03:55:05.79 |
+00:45:36.0 |
HIP 18408 |
15.92 |
| 2026-10-04 12:00 |
03:55:02.82 |
+00:42:49.9 |
HIP 18408 |
16.39 |
| 2026-10-05 00:00 |
03:54:59.41 |
+00:40:03.4 |
HIP 18408 |
17.44 |
| 2026-10-05 12:00 |
03:54:55.57 |
+00:37:16.5 |
HIP 18408 |
18.99 |
| 2026-10-06 00:00 |
03:54:51.29 |
+00:34:29.4 |
HIP 18408 |
20.94 |
| 2026-10-06 12:00 |
03:54:46.58 |
+00:31:42.1 |
HIP 18408 |
23.21 |
| 2026-10-07 00:00 |
03:54:41.43 |
+00:28:54.5 |
HIP 18408 |
25.73 |
| 2026-10-07 12:00 |
03:54:35.85 |
+00:26:06.8 |
HIP 18408 |
28.45 |
| 2026-10-08 00:00 |
03:54:29.83 |
+00:23:19.0 |
HIP 18226 |
28.29 |
| 2026-10-08 12:00 |
03:54:23.38 |
+00:20:31.1 |
HIP 18226 |
25.10 |
| 2026-10-09 00:00 |
03:54:16.49 |
+00:17:43.2 |
HIP 18226 |
21.89 |
| 2026-10-09 12:00 |
03:54:09.17 |
+00:14:55.3 |
HIP 18226 |
18.67 |
| 2026-10-10 00:00 |
03:54:01.41 |
+00:12:07.5 |
HIP 18226 |
15.49 |
| 2026-10-10 12:00 |
03:53:53.23 |
+00:09:19.8 |
HIP 18226 |
12.41 |
| 2026-10-11 00:00 |
03:53:44.61 |
+00:06:32.2 |
HIP 18226 |
9.62 |
| 2026-10-11 12:00 |
03:53:35.56 |
+00:03:44.8 |
HIP 18226 |
7.52 |
| 2026-10-12 00:00 |
03:53:26.09 |
+00:00:57.7 |
HIP 18226 |
6.90 |
| 2026-10-12 12:00 |
03:53:16.18 |
-00:01:49.1 |
HIP 18226 |
8.19 |
| 2026-10-13 00:00 |
03:53:05.86 |
-00:04:35.6 |
HIP 18226 |
10.80 |
| 2026-10-13 12:00 |
03:52:55.11 |
-00:07:21.7 |
HIP 18226 |
14.06 |
| 2026-10-14 00:00 |
03:52:43.94 |
-00:10:07.4 |
HIP 18226 |
17.66 |
| 2026-10-14 12:00 |
03:52:32.35 |
-00:12:52.6 |
HIP 18226 |
21.46 |
| 2026-10-15 00:00 |
03:52:20.34 |
-00:15:37.3 |
HIP 18109 |
23.73 |
| 2026-10-15 12:00 |
03:52:07.91 |
-00:18:21.4 |
HIP 18109 |
21.11 |
| 2026-10-16 00:00 |
03:51:55.08 |
-00:21:04.8 |
HIP 18109 |
19.07 |