P/2019 A6 (Lemmon-PANSTARRS)

Metadata

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

P/2019 A6 (Lemmon-PANSTARRS) · Magnitude (Full range)

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)
2026-07-29 00:00 17:52:17.86 -28:56:00.9 HIP 87419 10.37
2026-07-29 12:00 17:52:07.00 -28:55:18.0 HIP 87419 8.67
2026-07-30 00:00 17:51:56.24 -28:54:35.1 HIP 87419 7.42
2026-07-30 12:00 17:51:45.58 -28:53:52.0 HIP 87419 6.85
2026-07-31 00:00 17:51:35.04 -28:53:08.7 HIP 87419 7.11
2026-07-31 12:00 17:51:24.61 -28:52:25.4 HIP 87419 8.10
2026-08-01 00:00 17:51:14.28 -28:51:41.9 HIP 87419 9.58
2026-08-01 12:00 17:51:04.07 -28:50:58.3 HIP 87419 11.34
2026-08-02 00:00 17:50:53.97 -28:50:14.6 HIP 87419 13.26
2026-08-02 12:00 17:50:43.99 -28:49:30.7 HIP 87419 15.27
2026-08-03 00:00 17:50:34.11 -28:48:46.8 HIP 87419 17.33
2026-08-03 12:00 17:50:24.36 -28:48:02.8 HIP 87419 19.41
2026-08-04 00:00 17:50:14.72 -28:47:18.6 HIP 87419 21.51
2026-08-04 12:00 17:50:05.19 -28:46:34.4 HIP 87419 23.61
2026-08-05 00:00 17:49:55.79 -28:45:50.1 HIP 87419 25.70
2026-08-05 12:00 17:49:46.50 -28:45:05.7 HIP 87109 25.75
2026-08-06 00:00 17:49:37.33 -28:44:21.2 HIP 87109 23.61
2026-08-06 12:00 17:49:28.28 -28:43:36.6 HIP 87109 21.50
2026-08-07 00:00 17:49:19.35 -28:42:52.0 HIP 87109 19.41
2026-08-07 12:00 17:49:10.55 -28:42:07.2 HIP 87109 17.35
2026-08-08 00:00 17:49:01.87 -28:41:22.5 HIP 87109 15.32
2026-08-08 12:00 17:48:53.31 -28:40:37.6 HIP 87109 13.32
2026-08-09 00:00 17:48:44.88 -28:39:52.7 HIP 87109 11.35
2026-08-09 12:00 17:48:36.57 -28:39:07.7 HIP 87109 9.43
2026-08-10 00:00 17:48:28.39 -28:38:22.7 HIP 87109 7.55
2026-08-10 12:00 17:48:20.33 -28:37:37.6 HIP 87109 5.74
2026-08-11 00:00 17:48:12.40 -28:36:52.5 HIP 87109 4.06
2026-08-11 12:00 17:48:04.60 -28:36:07.3 HIP 87109 2.72
2026-08-12 00:00 17:47:56.93 -28:35:22.1 HIP 87109 2.31
2026-08-12 12:00 17:47:49.39 -28:34:36.9 HIP 87109 3.16
2026-08-13 00:00 17:47:41.98 -28:33:51.6 HIP 87109 4.60
2026-08-13 12:00 17:47:34.71 -28:33:06.3 HIP 87109 6.20
2026-08-14 00:00 17:47:27.56 -28:32:21.0 HIP 87109 7.86
2026-08-14 12:00 17:47:20.55 -28:31:35.6 HIP 87109 9.52
2026-08-15 00:00 17:47:13.66 -28:30:50.3 HIP 87109 11.17
2026-08-15 12:00 17:47:06.92 -28:30:04.9 HIP 87109 12.81
2026-08-16 00:00 17:47:00.30 -28:29:19.5 HIP 87109 14.44
2026-08-16 12:00 17:46:53.82 -28:28:34.1 HIP 87109 16.04
2026-08-17 00:00 17:46:47.48 -28:27:48.7 HIP 86919 15.78
2026-08-17 12:00 17:46:41.27 -28:27:03.3 HIP 86919 14.30
2026-08-18 00:00 17:46:35.19 -28:26:17.9 HIP 86919 12.86
2026-08-18 12:00 17:46:29.25 -28:25:32.5 HIP 86919 11.47
2026-08-19 00:00 17:46:23.45 -28:24:47.1 HIP 86919 10.15