| Parameter |
Value |
| Designation |
423P/Lemmon |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-09-24T00:20:08.096640Z |
| Orbit solution date (soln_date, UTC) |
2023-03-28T19:43:45Z |
| Obs used |
96 |
| NEO |
- |
| M1 |
13.800 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-02-19.0000000 |
| e |
0.12005480 |
| q (au) |
5.418519 |
| a (au) |
6.157791 |
| i (deg) |
8.348898 |
| Ω (om, deg) |
33.347491 |
| ω (w, deg) |
80.712810 |
| M (ma, deg) |
322.394999 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.108 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.108 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.778 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
15:46:08.19 |
-22:58:31.0 |
HIP 77155 |
14.04 |
| 2026-03-26 12:00 |
15:46:03.38 |
-22:58:45.0 |
HIP 77155 |
13.10 |
| 2026-03-27 00:00 |
15:45:58.40 |
-22:58:58.6 |
HIP 77155 |
12.17 |
| 2026-03-27 12:00 |
15:45:53.27 |
-22:59:11.6 |
HIP 77155 |
11.24 |
| 2026-03-28 00:00 |
15:45:47.98 |
-22:59:24.1 |
HIP 77155 |
10.33 |
| 2026-03-28 12:00 |
15:45:42.54 |
-22:59:36.0 |
HIP 77155 |
9.46 |
| 2026-03-29 00:00 |
15:45:36.94 |
-22:59:47.5 |
HIP 77155 |
8.67 |
| 2026-03-29 12:00 |
15:45:31.18 |
-22:59:58.4 |
HIP 77155 |
7.98 |
| 2026-03-30 00:00 |
15:45:25.27 |
-23:00:08.8 |
HIP 77155 |
7.44 |
| 2026-03-30 12:00 |
15:45:19.21 |
-23:00:18.6 |
HIP 77155 |
7.11 |
| 2026-03-31 00:00 |
15:45:12.99 |
-23:00:28.0 |
HIP 77123 |
6.83 |
| 2026-03-31 12:00 |
15:45:06.62 |
-23:00:36.8 |
HIP 77123 |
5.80 |
| 2026-04-01 00:00 |
15:45:00.10 |
-23:00:45.1 |
HIP 77123 |
5.00 |
| 2026-04-01 12:00 |
15:44:53.43 |
-23:00:52.8 |
HIP 77123 |
4.57 |
| 2026-04-02 00:00 |
15:44:46.61 |
-23:01:00.1 |
HIP 77123 |
4.66 |
| 2026-04-02 12:00 |
15:44:39.65 |
-23:01:06.7 |
HIP 77123 |
5.28 |
| 2026-04-03 00:00 |
15:44:32.53 |
-23:01:12.9 |
HIP 77123 |
6.28 |
| 2026-04-03 12:00 |
15:44:25.27 |
-23:01:18.6 |
HIP 77123 |
7.55 |
| 2026-04-04 00:00 |
15:44:17.86 |
-23:01:23.7 |
HIP 77123 |
8.98 |
| 2026-04-04 12:00 |
15:44:10.30 |
-23:01:28.2 |
HIP 77123 |
10.53 |
| 2026-04-05 00:00 |
15:44:02.60 |
-23:01:32.3 |
HIP 77123 |
12.17 |
| 2026-04-05 12:00 |
15:43:54.76 |
-23:01:35.8 |
HIP 77123 |
13.87 |
| 2026-04-06 00:00 |
15:43:46.78 |
-23:01:38.8 |
HIP 77123 |
15.64 |
| 2026-04-06 12:00 |
15:43:38.65 |
-23:01:41.2 |
HIP 77123 |
17.45 |
| 2026-04-07 00:00 |
15:43:30.38 |
-23:01:43.1 |
HIP 77123 |
19.30 |
| 2026-04-07 12:00 |
15:43:21.98 |
-23:01:44.5 |
HIP 76898 |
17.86 |
| 2026-04-08 00:00 |
15:43:13.43 |
-23:01:45.4 |
HIP 76898 |
15.89 |
| 2026-04-08 12:00 |
15:43:04.75 |
-23:01:45.7 |
HIP 76898 |
13.90 |
| 2026-04-09 00:00 |
15:42:55.93 |
-23:01:45.5 |
HIP 76898 |
11.87 |
| 2026-04-09 12:00 |
15:42:46.98 |
-23:01:44.7 |
HIP 76898 |
9.81 |
| 2026-04-10 00:00 |
15:42:37.89 |
-23:01:43.5 |
HIP 76898 |
7.72 |
| 2026-04-10 12:00 |
15:42:28.67 |
-23:01:41.7 |
HIP 76898 |
5.61 |
| 2026-04-11 00:00 |
15:42:19.32 |
-23:01:39.3 |
HIP 76898 |
3.48 |
| 2026-04-11 12:00 |
15:42:09.84 |
-23:01:36.5 |
HIP 76898 |
1.39 |
| 2026-04-12 00:00 |
15:42:00.23 |
-23:01:33.1 |
HIP 76898 |
1.15 |
| 2026-04-12 12:00 |
15:41:50.49 |
-23:01:29.2 |
HIP 76898 |
3.27 |
| 2026-04-13 00:00 |
15:41:40.62 |
-23:01:24.7 |
HIP 76898 |
5.52 |
| 2026-04-13 12:00 |
15:41:30.63 |
-23:01:19.7 |
HIP 76898 |
7.81 |
| 2026-04-14 00:00 |
15:41:20.52 |
-23:01:14.2 |
HIP 76898 |
10.14 |
| 2026-04-14 12:00 |
15:41:10.28 |
-23:01:08.2 |
HIP 76898 |
12.49 |
| 2026-04-15 00:00 |
15:40:59.93 |
-23:01:01.7 |
HIP 76898 |
14.88 |
| 2026-04-15 12:00 |
15:40:49.45 |
-23:00:54.6 |
HIP 76898 |
17.29 |
| 2026-04-16 00:00 |
15:40:38.86 |
-23:00:47.0 |
HIP 76666 |
19.62 |