| 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) |
| 2026-05-12 00:00 |
18:26:35.87 |
-29:54:23.9 |
HIP 90450 |
16.41 |
| 2026-05-12 12:00 |
18:26:26.74 |
-29:54:21.5 |
HIP 90450 |
17.71 |
| 2026-05-13 00:00 |
18:26:17.48 |
-29:54:18.9 |
HIP 90450 |
19.15 |
| 2026-05-13 12:00 |
18:26:08.10 |
-29:54:16.1 |
HIP 90450 |
20.70 |
| 2026-05-14 00:00 |
18:25:58.60 |
-29:54:13.2 |
HIP 90300 |
21.87 |
| 2026-05-14 12:00 |
18:25:48.98 |
-29:54:10.1 |
HIP 90300 |
21.43 |
| 2026-05-15 00:00 |
18:25:39.25 |
-29:54:06.9 |
HIP 90300 |
21.18 |
| 2026-05-15 12:00 |
18:25:29.39 |
-29:54:03.6 |
HIP 90300 |
21.15 |
| 2026-05-16 00:00 |
18:25:19.42 |
-29:54:00.0 |
HIP 90300 |
21.33 |
| 2026-05-16 12:00 |
18:25:09.34 |
-29:53:56.3 |
HIP 90300 |
21.73 |
| 2026-05-17 00:00 |
18:24:59.14 |
-29:53:52.5 |
HIP 90213 |
22.36 |
| 2026-05-17 12:00 |
18:24:48.83 |
-29:53:48.4 |
HIP 90213 |
21.69 |
| 2026-05-18 00:00 |
18:24:38.40 |
-29:53:44.2 |
HIP 90213 |
21.24 |
| 2026-05-18 12:00 |
18:24:27.87 |
-29:53:39.8 |
HIP 90213 |
21.02 |
| 2026-05-19 00:00 |
18:24:17.22 |
-29:53:35.2 |
HIP 90213 |
21.04 |
| 2026-05-19 12:00 |
18:24:06.47 |
-29:53:30.5 |
HIP 90213 |
21.32 |
| 2026-05-20 00:00 |
18:23:55.60 |
-29:53:25.5 |
HIP 90213 |
21.86 |
| 2026-05-20 12:00 |
18:23:44.64 |
-29:53:20.4 |
HIP 90213 |
22.63 |
| 2026-05-21 00:00 |
18:23:33.56 |
-29:53:15.0 |
HIP 90213 |
23.63 |
| 2026-05-21 12:00 |
18:23:22.38 |
-29:53:09.4 |
HIP 90213 |
24.83 |
| 2026-05-22 00:00 |
18:23:11.10 |
-29:53:03.7 |
HIP 90213 |
26.21 |
| 2026-05-22 12:00 |
18:22:59.72 |
-29:52:57.7 |
HIP 90011 |
25.09 |
| 2026-05-23 00:00 |
18:22:48.24 |
-29:52:51.5 |
HIP 89931 |
23.76 |
| 2026-05-23 12:00 |
18:22:36.66 |
-29:52:45.1 |
HIP 89931 |
21.26 |
| 2026-05-24 00:00 |
18:22:24.98 |
-29:52:38.5 |
HIP 89931 |
18.74 |
| 2026-05-24 12:00 |
18:22:13.20 |
-29:52:31.6 |
HIP 89931 |
16.21 |
| 2026-05-25 00:00 |
18:22:01.33 |
-29:52:24.6 |
HIP 89931 |
13.66 |
| 2026-05-25 12:00 |
18:21:49.36 |
-29:52:17.3 |
HIP 89931 |
11.10 |
| 2026-05-26 00:00 |
18:21:37.31 |
-29:52:09.7 |
HIP 89931 |
8.54 |
| 2026-05-26 12:00 |
18:21:25.15 |
-29:52:01.9 |
HIP 89931 |
6.01 |
| 2026-05-27 00:00 |
18:21:12.91 |
-29:51:53.9 |
HIP 89931 |
3.64 |
| 2026-05-27 12:00 |
18:21:00.58 |
-29:51:45.7 |
HIP 89931 |
2.09 |
| 2026-05-28 00:00 |
18:20:48.17 |
-29:51:37.2 |
HIP 89931 |
3.15 |
| 2026-05-28 12:00 |
18:20:35.66 |
-29:51:28.4 |
HIP 89931 |
5.50 |
| 2026-05-29 00:00 |
18:20:23.07 |
-29:51:19.4 |
HIP 89931 |
8.09 |
| 2026-05-29 12:00 |
18:20:10.40 |
-29:51:10.2 |
HIP 89931 |
10.78 |
| 2026-05-30 00:00 |
18:19:57.64 |
-29:51:00.7 |
HIP 89931 |
13.51 |
| 2026-05-30 12:00 |
18:19:44.80 |
-29:50:50.9 |
HIP 89811 |
13.67 |
| 2026-05-31 00:00 |
18:19:31.88 |
-29:50:40.9 |
HIP 89811 |
13.67 |
| 2026-05-31 12:00 |
18:19:18.88 |
-29:50:30.6 |
HIP 89811 |
14.24 |
| 2026-06-01 00:00 |
18:19:05.81 |
-29:50:20.0 |
HIP 89716 |
14.65 |
| 2026-06-01 12:00 |
18:18:52.66 |
-29:50:09.2 |
HIP 89716 |
13.72 |
| 2026-06-02 00:00 |
18:18:39.43 |
-29:49:58.1 |
HIP 89716 |
13.34 |