C/2019 J1 (Lemmon)
| 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 · 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 |
1.000 |
| gb |
-0.650 |
| k |
0.897 |
| 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) |
| 2026-02-03 00:00 |
03:07:10.84 |
-02:54:04.5 |
HIP 14397 |
21.62 |
| 2026-02-03 12:00 |
03:07:11.03 |
-02:53:24.2 |
HIP 14397 |
21.72 |
| 2026-02-04 00:00 |
03:07:11.27 |
-02:52:43.6 |
HIP 14397 |
21.86 |
| 2026-02-04 12:00 |
03:07:11.57 |
-02:52:02.9 |
HIP 14397 |
22.03 |
| 2026-02-05 00:00 |
03:07:11.93 |
-02:51:22.0 |
HIP 14397 |
22.24 |
| 2026-02-05 12:00 |
03:07:12.35 |
-02:50:40.8 |
HIP 14397 |
22.48 |
| 2026-02-06 00:00 |
03:07:12.82 |
-02:49:59.5 |
HIP 14397 |
22.75 |
| 2026-02-06 12:00 |
03:07:13.35 |
-02:49:18.0 |
HIP 14397 |
23.06 |
| 2026-02-07 00:00 |
03:07:13.93 |
-02:48:36.3 |
HIP 14397 |
23.39 |
| 2026-02-07 12:00 |
03:07:14.58 |
-02:47:54.4 |
HIP 14397 |
23.76 |
| 2026-02-08 00:00 |
03:07:15.27 |
-02:47:12.3 |
HIP 14397 |
24.16 |
| 2026-02-08 12:00 |
03:07:16.03 |
-02:46:30.0 |
HIP 14397 |
24.59 |
| 2026-02-09 00:00 |
03:07:16.84 |
-02:45:47.6 |
HIP 14397 |
25.05 |
| 2026-02-09 12:00 |
03:07:17.71 |
-02:45:05.0 |
HIP 14397 |
25.53 |
| 2026-02-10 00:00 |
03:07:18.63 |
-02:44:22.2 |
HIP 14397 |
26.04 |
| 2026-02-10 12:00 |
03:07:19.62 |
-02:43:39.2 |
HIP 14397 |
26.57 |
| 2026-02-11 00:00 |
03:07:20.65 |
-02:42:56.1 |
HIP 14397 |
27.13 |
| 2026-02-11 12:00 |
03:07:21.75 |
-02:42:12.8 |
HIP 14397 |
27.71 |
| 2026-02-12 00:00 |
03:07:22.89 |
-02:41:29.3 |
HIP 14397 |
28.32 |
| 2026-02-12 12:00 |
03:07:24.10 |
-02:40:45.7 |
HIP 14397 |
28.94 |
| 2026-02-13 00:00 |
03:07:25.36 |
-02:40:02.0 |
HIP 14397 |
29.59 |
| 2026-02-13 12:00 |
03:07:26.67 |
-02:39:18.1 |
HIP 14397 |
30.26 |
| 2026-02-14 00:00 |
03:07:28.05 |
-02:38:34.0 |
HIP 14397 |
30.94 |
| 2026-02-14 12:00 |
03:07:29.47 |
-02:37:49.8 |
HIP 14397 |
31.65 |
| 2026-02-15 00:00 |
03:07:30.95 |
-02:37:05.4 |
HIP 14397 |
32.37 |
| 2026-02-15 12:00 |
03:07:32.49 |
-02:36:21.0 |
HIP 14397 |
33.11 |
| 2026-02-16 00:00 |
03:07:34.08 |
-02:35:36.3 |
HIP 14397 |
33.87 |
| 2026-02-16 12:00 |
03:07:35.73 |
-02:34:51.6 |
HIP 14397 |
34.64 |
| 2026-02-17 00:00 |
03:07:37.43 |
-02:34:06.7 |
HIP 14397 |
35.43 |
| 2026-02-17 12:00 |
03:07:39.18 |
-02:33:21.7 |
HIP 14397 |
36.24 |
| 2026-02-18 00:00 |
03:07:40.99 |
-02:32:36.6 |
HIP 14397 |
37.05 |
| 2026-02-18 12:00 |
03:07:42.85 |
-02:31:51.3 |
HIP 14397 |
37.89 |
| 2026-02-19 00:00 |
03:07:44.77 |
-02:31:05.9 |
HIP 14397 |
38.74 |
| 2026-02-19 12:00 |
03:07:46.74 |
-02:30:20.5 |
HIP 14397 |
39.60 |
| 2026-02-20 00:00 |
03:07:48.76 |
-02:29:34.9 |
HIP 14397 |
40.47 |
| 2026-02-20 12:00 |
03:07:50.84 |
-02:28:49.2 |
HIP 14397 |
41.36 |
| 2026-02-21 00:00 |
03:07:52.97 |
-02:28:03.4 |
HIP 14494 |
41.13 |
| 2026-02-21 12:00 |
03:07:55.15 |
-02:27:17.5 |
HIP 14494 |
40.53 |
| 2026-02-22 00:00 |
03:07:57.38 |
-02:26:31.5 |
HIP 14494 |
39.94 |
| 2026-02-22 12:00 |
03:07:59.67 |
-02:25:45.4 |
HIP 14494 |
39.37 |
| 2026-02-23 00:00 |
03:08:02.01 |
-02:24:59.2 |
HIP 14494 |
38.82 |
| 2026-02-23 12:00 |
03:08:04.40 |
-02:24:13.0 |
HIP 14494 |
38.29 |
| 2026-02-24 00:00 |
03:08:06.84 |
-02:23:26.6 |
HIP 14494 |
37.77 |