| Parameter |
Value |
| Designation |
P/2019 A6 (Lemmon-PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-08-29T07:25:19.718400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:50Z |
| Obs used |
55 |
| NEO |
- |
| M1 |
17.900 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-01-07T12:20:51.936000Z |
| Discovery magnitude (MPC) |
20.70 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-01-05.0000000 |
| e |
0.63917742 |
| q (au) |
1.938506 |
| a (au) |
5.372463 |
| i (deg) |
33.228328 |
| Ω (om, deg) |
280.271890 |
| ω (w, deg) |
156.305004 |
| M (ma, deg) |
10.185707 |
Magnitude
Scatter + Global Linear
$$
M_a = (18.765 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
18.765 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.558 |
| 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) |
| 2026-03-26 00:00 |
18:30:54.64 |
-29:55:21.7 |
HIP 90648 |
16.14 |
| 2026-03-26 12:00 |
18:30:58.26 |
-29:55:19.2 |
HIP 90648 |
16.86 |
| 2026-03-27 00:00 |
18:31:01.76 |
-29:55:16.9 |
HIP 90648 |
17.57 |
| 2026-03-27 12:00 |
18:31:05.12 |
-29:55:14.6 |
HIP 90648 |
18.25 |
| 2026-03-28 00:00 |
18:31:08.35 |
-29:55:12.5 |
HIP 90881 |
18.42 |
| 2026-03-28 12:00 |
18:31:11.45 |
-29:55:10.4 |
HIP 90881 |
17.84 |
| 2026-03-29 00:00 |
18:31:14.41 |
-29:55:08.4 |
HIP 90881 |
17.30 |
| 2026-03-29 12:00 |
18:31:17.24 |
-29:55:06.5 |
HIP 90881 |
16.79 |
| 2026-03-30 00:00 |
18:31:19.94 |
-29:55:04.7 |
HIP 90881 |
16.31 |
| 2026-03-30 12:00 |
18:31:22.50 |
-29:55:02.9 |
HIP 90881 |
15.86 |
| 2026-03-31 00:00 |
18:31:24.94 |
-29:55:01.3 |
HIP 90881 |
15.45 |
| 2026-03-31 12:00 |
18:31:27.23 |
-29:54:59.7 |
HIP 90881 |
15.06 |
| 2026-04-01 00:00 |
18:31:29.39 |
-29:54:58.2 |
HIP 90881 |
14.70 |
| 2026-04-01 12:00 |
18:31:31.42 |
-29:54:56.8 |
HIP 90881 |
14.36 |
| 2026-04-02 00:00 |
18:31:33.31 |
-29:54:55.4 |
HIP 90881 |
14.06 |
| 2026-04-02 12:00 |
18:31:35.07 |
-29:54:54.2 |
HIP 90881 |
13.78 |
| 2026-04-03 00:00 |
18:31:36.69 |
-29:54:53.0 |
HIP 90881 |
13.52 |
| 2026-04-03 12:00 |
18:31:38.17 |
-29:54:51.9 |
HIP 90881 |
13.30 |
| 2026-04-04 00:00 |
18:31:39.52 |
-29:54:50.8 |
HIP 90881 |
13.09 |
| 2026-04-04 12:00 |
18:31:40.73 |
-29:54:49.9 |
HIP 90881 |
12.91 |
| 2026-04-05 00:00 |
18:31:41.80 |
-29:54:49.0 |
HIP 90881 |
12.75 |
| 2026-04-05 12:00 |
18:31:42.74 |
-29:54:48.1 |
HIP 90881 |
12.62 |
| 2026-04-06 00:00 |
18:31:43.54 |
-29:54:47.4 |
HIP 90881 |
12.50 |
| 2026-04-06 12:00 |
18:31:44.20 |
-29:54:46.7 |
HIP 90881 |
12.40 |
| 2026-04-07 00:00 |
18:31:44.72 |
-29:54:46.0 |
HIP 90881 |
12.33 |
| 2026-04-07 12:00 |
18:31:45.10 |
-29:54:45.5 |
HIP 90881 |
12.27 |
| 2026-04-08 00:00 |
18:31:45.35 |
-29:54:45.0 |
HIP 90881 |
12.23 |
| 2026-04-08 12:00 |
18:31:45.45 |
-29:54:44.5 |
HIP 90881 |
12.21 |
| 2026-04-09 00:00 |
18:31:45.42 |
-29:54:44.1 |
HIP 90881 |
12.21 |
| 2026-04-09 12:00 |
18:31:45.24 |
-29:54:43.8 |
HIP 90881 |
12.23 |
| 2026-04-10 00:00 |
18:31:44.93 |
-29:54:43.5 |
HIP 90881 |
12.26 |
| 2026-04-10 12:00 |
18:31:44.48 |
-29:54:43.3 |
HIP 90881 |
12.32 |
| 2026-04-11 00:00 |
18:31:43.88 |
-29:54:43.1 |
HIP 90881 |
12.40 |
| 2026-04-11 12:00 |
18:31:43.15 |
-29:54:42.9 |
HIP 90881 |
12.49 |
| 2026-04-12 00:00 |
18:31:42.27 |
-29:54:42.8 |
HIP 90881 |
12.61 |
| 2026-04-12 12:00 |
18:31:41.26 |
-29:54:42.8 |
HIP 90881 |
12.75 |
| 2026-04-13 00:00 |
18:31:40.10 |
-29:54:42.8 |
HIP 90881 |
12.91 |
| 2026-04-13 12:00 |
18:31:38.80 |
-29:54:42.8 |
HIP 90881 |
13.09 |
| 2026-04-14 00:00 |
18:31:37.37 |
-29:54:42.9 |
HIP 90881 |
13.30 |
| 2026-04-14 12:00 |
18:31:35.78 |
-29:54:43.0 |
HIP 90881 |
13.54 |
| 2026-04-15 00:00 |
18:31:34.06 |
-29:54:43.2 |
HIP 90881 |
13.80 |
| 2026-04-15 12:00 |
18:31:32.20 |
-29:54:43.4 |
HIP 90881 |
14.09 |
| 2026-04-16 00:00 |
18:31:30.19 |
-29:54:43.6 |
HIP 90881 |
14.40 |