| 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) |
| 2026-09-20 00:00 |
17:45:00.64 |
-27:38:28.6 |
HIP 86803 |
12.45 |
| 2026-09-20 12:00 |
17:45:03.82 |
-27:37:48.4 |
HIP 86803 |
13.41 |
| 2026-09-21 00:00 |
17:45:07.14 |
-27:37:08.2 |
HIP 86803 |
14.40 |
| 2026-09-21 12:00 |
17:45:10.59 |
-27:36:28.2 |
HIP 86803 |
15.42 |
| 2026-09-22 00:00 |
17:45:14.17 |
-27:35:48.4 |
HIP 86803 |
16.45 |
| 2026-09-22 12:00 |
17:45:17.88 |
-27:35:08.6 |
HIP 86803 |
17.50 |
| 2026-09-23 00:00 |
17:45:21.72 |
-27:34:28.9 |
HIP 86803 |
18.58 |
| 2026-09-23 12:00 |
17:45:25.69 |
-27:33:49.4 |
HIP 86803 |
19.68 |
| 2026-09-24 00:00 |
17:45:29.79 |
-27:33:10.0 |
HIP 86803 |
20.80 |
| 2026-09-24 12:00 |
17:45:34.02 |
-27:32:30.7 |
HIP 86803 |
21.94 |
| 2026-09-25 00:00 |
17:45:38.37 |
-27:31:51.6 |
HIP 86803 |
23.11 |
| 2026-09-25 12:00 |
17:45:42.86 |
-27:31:12.5 |
HIP 86803 |
24.29 |
| 2026-09-26 00:00 |
17:45:47.47 |
-27:30:33.6 |
HIP 86803 |
25.50 |
| 2026-09-26 12:00 |
17:45:52.21 |
-27:29:54.8 |
HIP 86803 |
26.73 |
| 2026-09-27 00:00 |
17:45:57.08 |
-27:29:16.1 |
HIP 86803 |
27.98 |
| 2026-09-27 12:00 |
17:46:02.08 |
-27:28:37.5 |
HIP 87128 |
27.67 |
| 2026-09-28 00:00 |
17:46:07.20 |
-27:27:59.1 |
HIP 87128 |
26.50 |
| 2026-09-28 12:00 |
17:46:12.44 |
-27:27:20.7 |
HIP 87128 |
25.32 |
| 2026-09-29 00:00 |
17:46:17.81 |
-27:26:42.5 |
HIP 87128 |
24.12 |
| 2026-09-29 12:00 |
17:46:23.30 |
-27:26:04.4 |
HIP 87128 |
22.91 |
| 2026-09-30 00:00 |
17:46:28.92 |
-27:25:26.4 |
HIP 87128 |
21.70 |
| 2026-09-30 12:00 |
17:46:34.66 |
-27:24:48.6 |
HIP 87128 |
20.48 |
| 2026-10-01 00:00 |
17:46:40.53 |
-27:24:10.8 |
HIP 87128 |
19.26 |
| 2026-10-01 12:00 |
17:46:46.52 |
-27:23:33.2 |
HIP 87128 |
18.05 |
| 2026-10-02 00:00 |
17:46:52.63 |
-27:22:55.7 |
HIP 87128 |
16.85 |
| 2026-10-02 12:00 |
17:46:58.86 |
-27:22:18.2 |
HIP 87128 |
15.67 |
| 2026-10-03 00:00 |
17:47:05.21 |
-27:21:41.0 |
HIP 87128 |
14.53 |
| 2026-10-03 12:00 |
17:47:11.69 |
-27:21:03.8 |
HIP 87128 |
13.44 |
| 2026-10-04 00:00 |
17:47:18.28 |
-27:20:26.7 |
HIP 87128 |
12.44 |
| 2026-10-04 12:00 |
17:47:25.00 |
-27:19:49.8 |
HIP 87128 |
11.54 |
| 2026-10-05 00:00 |
17:47:31.84 |
-27:19:12.9 |
HIP 87128 |
10.79 |
| 2026-10-05 12:00 |
17:47:38.79 |
-27:18:36.2 |
HIP 87128 |
10.23 |
| 2026-10-06 00:00 |
17:47:45.87 |
-27:17:59.6 |
HIP 87128 |
9.91 |
| 2026-10-06 12:00 |
17:47:53.06 |
-27:17:23.1 |
HIP 87128 |
9.85 |
| 2026-10-07 00:00 |
17:48:00.37 |
-27:16:46.7 |
HIP 87128 |
10.09 |
| 2026-10-07 12:00 |
17:48:07.80 |
-27:16:10.4 |
HIP 87128 |
10.60 |
| 2026-10-08 00:00 |
17:48:15.34 |
-27:15:34.2 |
HIP 87128 |
11.37 |
| 2026-10-08 12:00 |
17:48:23.00 |
-27:14:58.1 |
HIP 87128 |
12.36 |
| 2026-10-09 00:00 |
17:48:30.78 |
-27:14:22.1 |
HIP 87128 |
13.52 |
| 2026-10-09 12:00 |
17:48:38.67 |
-27:13:46.3 |
HIP 87128 |
14.83 |
| 2026-10-10 00:00 |
17:48:46.68 |
-27:13:10.5 |
HIP 87163 |
15.27 |
| 2026-10-10 12:00 |
17:48:54.80 |
-27:12:34.8 |
HIP 87163 |
15.31 |
| 2026-10-11 00:00 |
17:49:03.03 |
-27:11:59.3 |
HIP 87163 |
15.60 |