| Parameter |
Value |
| Designation |
C/2019 Q1 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-07-19T15:31:26.172480Z |
| Orbit solution date (soln_date, UTC) |
2024-03-12T13:12:25Z |
| Obs used |
248 |
| NEO |
- |
| M1 |
13.900 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-08-28T09:37:41.952000Z |
| Discovery magnitude (MPC) |
20.60 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-04-08.0000000 |
| e |
1.00092868 |
| q (au) |
4.997085 |
| a (au) |
-5380.822928 |
| i (deg) |
155.721870 |
| Ω (om, deg) |
42.338664 |
| ω (w, deg) |
55.917769 |
| M (ma, deg) |
-0.000256 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.131 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.131 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.790 |
| 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 |
15:21:49.31 |
-13:06:21.4 |
HIP 75116 |
12.90 |
| 2026-09-20 12:00 |
15:21:52.09 |
-13:06:49.9 |
HIP 75116 |
13.39 |
| 2026-09-21 00:00 |
15:21:54.92 |
-13:07:18.4 |
HIP 75116 |
13.93 |
| 2026-09-21 12:00 |
15:21:57.79 |
-13:07:47.0 |
HIP 75116 |
14.51 |
| 2026-09-22 00:00 |
15:22:00.71 |
-13:08:15.8 |
HIP 75116 |
15.12 |
| 2026-09-22 12:00 |
15:22:03.68 |
-13:08:44.6 |
HIP 75116 |
15.77 |
| 2026-09-23 00:00 |
15:22:06.70 |
-13:09:13.6 |
HIP 75116 |
16.44 |
| 2026-09-23 12:00 |
15:22:09.76 |
-13:09:42.6 |
HIP 75116 |
17.15 |
| 2026-09-24 00:00 |
15:22:12.87 |
-13:10:11.7 |
HIP 75116 |
17.89 |
| 2026-09-24 12:00 |
15:22:16.03 |
-13:10:41.0 |
HIP 75116 |
18.65 |
| 2026-09-25 00:00 |
15:22:19.23 |
-13:11:10.3 |
HIP 75116 |
19.43 |
| 2026-09-25 12:00 |
15:22:22.48 |
-13:11:39.8 |
HIP 75116 |
20.24 |
| 2026-09-26 00:00 |
15:22:25.77 |
-13:12:09.3 |
HIP 75116 |
21.07 |
| 2026-09-26 12:00 |
15:22:29.10 |
-13:12:38.9 |
HIP 75116 |
21.92 |
| 2026-09-27 00:00 |
15:22:32.48 |
-13:13:08.6 |
HIP 75116 |
22.78 |
| 2026-09-27 12:00 |
15:22:35.90 |
-13:13:38.4 |
HIP 75116 |
23.67 |
| 2026-09-28 00:00 |
15:22:39.37 |
-13:14:08.3 |
HIP 75116 |
24.57 |
| 2026-09-28 12:00 |
15:22:42.88 |
-13:14:38.2 |
HIP 75116 |
25.49 |
| 2026-09-29 00:00 |
15:22:46.43 |
-13:15:08.3 |
HIP 75416 |
26.41 |
| 2026-09-29 12:00 |
15:22:50.02 |
-13:15:38.4 |
HIP 75416 |
25.43 |
| 2026-09-30 00:00 |
15:22:53.66 |
-13:16:08.6 |
HIP 75416 |
24.45 |
| 2026-09-30 12:00 |
15:22:57.33 |
-13:16:38.9 |
HIP 75416 |
23.46 |
| 2026-10-01 00:00 |
15:23:01.05 |
-13:17:09.2 |
HIP 75416 |
22.46 |
| 2026-10-01 12:00 |
15:23:04.81 |
-13:17:39.7 |
HIP 75416 |
21.46 |
| 2026-10-02 00:00 |
15:23:08.61 |
-13:18:10.2 |
HIP 75416 |
20.45 |
| 2026-10-02 12:00 |
15:23:12.45 |
-13:18:40.8 |
HIP 75416 |
19.43 |
| 2026-10-03 00:00 |
15:23:16.33 |
-13:19:11.4 |
HIP 75416 |
18.41 |
| 2026-10-03 12:00 |
15:23:20.25 |
-13:19:42.1 |
HIP 75416 |
17.39 |
| 2026-10-04 00:00 |
15:23:24.21 |
-13:20:12.9 |
HIP 75416 |
16.37 |
| 2026-10-04 12:00 |
15:23:28.20 |
-13:20:43.7 |
HIP 75416 |
15.34 |
| 2026-10-05 00:00 |
15:23:32.24 |
-13:21:14.6 |
HIP 75416 |
14.32 |
| 2026-10-05 12:00 |
15:23:36.31 |
-13:21:45.6 |
HIP 75416 |
13.30 |
| 2026-10-06 00:00 |
15:23:40.43 |
-13:22:16.6 |
HIP 75416 |
12.29 |
| 2026-10-06 12:00 |
15:23:44.57 |
-13:22:47.7 |
HIP 75416 |
11.30 |
| 2026-10-07 00:00 |
15:23:48.76 |
-13:23:18.8 |
HIP 75416 |
10.32 |
| 2026-10-07 12:00 |
15:23:52.98 |
-13:23:50.0 |
HIP 75416 |
9.37 |
| 2026-10-08 00:00 |
15:23:57.24 |
-13:24:21.2 |
HIP 75416 |
8.47 |
| 2026-10-08 12:00 |
15:24:01.54 |
-13:24:52.5 |
HIP 75416 |
7.62 |
| 2026-10-09 00:00 |
15:24:05.87 |
-13:25:23.8 |
HIP 75416 |
6.87 |
| 2026-10-09 12:00 |
15:24:10.23 |
-13:25:55.2 |
HIP 75416 |
6.24 |
| 2026-10-10 00:00 |
15:24:14.63 |
-13:26:26.6 |
HIP 75416 |
5.78 |
| 2026-10-10 12:00 |
15:24:19.06 |
-13:26:58.0 |
HIP 75416 |
5.53 |
| 2026-10-11 00:00 |
15:24:23.53 |
-13:27:29.5 |
HIP 75416 |
5.54 |