| Parameter |
Value |
| Designation |
C/2019 J1 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-04-09T08:09:59.362560Z |
| Orbit solution date (soln_date, UTC) |
2023-01-14T00:12:30Z |
| Obs used |
192 |
| NEO |
- |
| M1 |
12.000 |
| K1 |
11.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-05-04T10:44:49.920000Z |
| Discovery magnitude (MPC) |
17.40 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-06-18.0000000 |
| e |
0.96535584 |
| q (au) |
2.478657 |
| a (au) |
71.546171 |
| i (deg) |
24.549745 |
| Ω (om, deg) |
98.087033 |
| ω (w, deg) |
167.794427 |
| M (ma, deg) |
0.113450 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.407 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.407 |
| n |
6.000 |
| gf |
0.982 |
| gb |
-0.650 |
| k |
0.897 |
| δ90 |
9.997 |
| 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) |
| 2026-06-01 00:00 |
03:25:55.88 |
-00:19:27.9 |
HIP 16000 |
19.29 |
| 2026-06-01 12:00 |
03:26:02.26 |
-00:19:10.1 |
HIP 16000 |
19.47 |
| 2026-06-02 00:00 |
03:26:08.62 |
-00:18:52.6 |
HIP 16000 |
19.79 |
| 2026-06-02 12:00 |
03:26:14.96 |
-00:18:35.4 |
HIP 16000 |
20.22 |
| 2026-06-03 00:00 |
03:26:21.29 |
-00:18:18.5 |
HIP 16000 |
20.77 |
| 2026-06-03 12:00 |
03:26:27.61 |
-00:18:01.9 |
HIP 16058 |
20.33 |
| 2026-06-04 00:00 |
03:26:33.91 |
-00:17:45.6 |
HIP 16058 |
19.71 |
| 2026-06-04 12:00 |
03:26:40.20 |
-00:17:29.6 |
HIP 16058 |
19.20 |
| 2026-06-05 00:00 |
03:26:46.47 |
-00:17:13.9 |
HIP 16058 |
18.81 |
| 2026-06-05 12:00 |
03:26:52.72 |
-00:16:58.4 |
HIP 16058 |
18.56 |
| 2026-06-06 00:00 |
03:26:58.95 |
-00:16:43.3 |
HIP 16058 |
18.45 |
| 2026-06-06 12:00 |
03:27:05.17 |
-00:16:28.5 |
HIP 16058 |
18.48 |
| 2026-06-07 00:00 |
03:27:11.37 |
-00:16:14.0 |
HIP 16058 |
18.64 |
| 2026-06-07 12:00 |
03:27:17.56 |
-00:15:59.8 |
HIP 16058 |
18.94 |
| 2026-06-08 00:00 |
03:27:23.72 |
-00:15:45.9 |
HIP 16058 |
19.36 |
| 2026-06-08 12:00 |
03:27:29.87 |
-00:15:32.3 |
HIP 16058 |
19.90 |
| 2026-06-09 00:00 |
03:27:36.00 |
-00:15:19.0 |
HIP 16058 |
20.54 |
| 2026-06-09 12:00 |
03:27:42.11 |
-00:15:06.0 |
HIP 16214 |
20.64 |
| 2026-06-10 00:00 |
03:27:48.20 |
-00:14:53.3 |
HIP 16214 |
19.43 |
| 2026-06-10 12:00 |
03:27:54.27 |
-00:14:40.9 |
HIP 16214 |
18.27 |
| 2026-06-11 00:00 |
03:28:00.31 |
-00:14:28.9 |
HIP 16214 |
17.17 |
| 2026-06-11 12:00 |
03:28:06.34 |
-00:14:17.1 |
HIP 16214 |
16.13 |
| 2026-06-12 00:00 |
03:28:12.35 |
-00:14:05.7 |
HIP 16214 |
15.18 |
| 2026-06-12 12:00 |
03:28:18.34 |
-00:13:54.5 |
HIP 16214 |
14.33 |
| 2026-06-13 00:00 |
03:28:24.30 |
-00:13:43.7 |
HIP 16214 |
13.59 |
| 2026-06-13 12:00 |
03:28:30.24 |
-00:13:33.2 |
HIP 16214 |
12.98 |
| 2026-06-14 00:00 |
03:28:36.16 |
-00:13:23.0 |
HIP 16214 |
12.52 |
| 2026-06-14 12:00 |
03:28:42.06 |
-00:13:13.1 |
HIP 16214 |
12.22 |
| 2026-06-15 00:00 |
03:28:47.94 |
-00:13:03.5 |
HIP 16214 |
12.09 |
| 2026-06-15 12:00 |
03:28:53.79 |
-00:12:54.2 |
HIP 16214 |
12.14 |
| 2026-06-16 00:00 |
03:28:59.61 |
-00:12:45.2 |
HIP 16214 |
12.35 |
| 2026-06-16 12:00 |
03:29:05.42 |
-00:12:36.6 |
HIP 16214 |
12.73 |
| 2026-06-17 00:00 |
03:29:11.19 |
-00:12:28.3 |
HIP 16214 |
13.25 |
| 2026-06-17 12:00 |
03:29:16.95 |
-00:12:20.2 |
HIP 16214 |
13.89 |
| 2026-06-18 00:00 |
03:29:22.68 |
-00:12:12.5 |
HIP 16214 |
14.64 |
| 2026-06-18 12:00 |
03:29:28.38 |
-00:12:05.1 |
HIP 16214 |
15.48 |
| 2026-06-19 00:00 |
03:29:34.05 |
-00:11:58.1 |
HIP 16214 |
16.40 |
| 2026-06-19 12:00 |
03:29:39.70 |
-00:11:51.3 |
HIP 16214 |
17.37 |
| 2026-06-20 00:00 |
03:29:45.33 |
-00:11:44.8 |
HIP 16214 |
18.40 |
| 2026-06-20 12:00 |
03:29:50.92 |
-00:11:38.7 |
HIP 16377 |
17.67 |
| 2026-06-21 00:00 |
03:29:56.49 |
-00:11:32.9 |
HIP 16377 |
16.30 |
| 2026-06-21 12:00 |
03:30:02.04 |
-00:11:27.4 |
HIP 16377 |
14.93 |
| 2026-06-22 00:00 |
03:30:07.55 |
-00:11:22.2 |
HIP 16377 |
13.58 |