| Parameter |
Value |
| Designation |
C/2020 B2 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-01-26T06:53:39.419520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:34:04Z |
| Obs used |
106 |
| NEO |
- |
| M1 |
17.200 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-02-04.0000000 |
| e |
0.95922180 |
| q (au) |
2.768047 |
| a (au) |
67.880568 |
| i (deg) |
55.704138 |
| Ω (om, deg) |
354.338868 |
| ω (w, deg) |
143.629671 |
| M (ma, deg) |
0.015355 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.433 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.433 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-1.000 |
| k |
0.998 |
| 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) |
| 2026-06-01 00:00 |
20:20:07.00 |
-79:38:28.9 |
HIP 100416 |
5.06 |
| 2026-06-01 12:00 |
20:19:46.89 |
-79:39:41.8 |
HIP 100416 |
6.49 |
| 2026-06-02 00:00 |
20:19:26.43 |
-79:40:54.1 |
HIP 100416 |
7.95 |
| 2026-06-02 12:00 |
20:19:05.63 |
-79:42:06.0 |
HIP 100416 |
9.44 |
| 2026-06-03 00:00 |
20:18:44.49 |
-79:43:17.3 |
HIP 100416 |
10.93 |
| 2026-06-03 12:00 |
20:18:23.01 |
-79:44:28.2 |
HIP 100416 |
12.44 |
| 2026-06-04 00:00 |
20:18:01.19 |
-79:45:38.4 |
HIP 100416 |
13.95 |
| 2026-06-04 12:00 |
20:17:39.03 |
-79:46:48.2 |
HIP 100416 |
15.46 |
| 2026-06-05 00:00 |
20:17:16.53 |
-79:47:57.4 |
HIP 100416 |
16.98 |
| 2026-06-05 12:00 |
20:16:53.69 |
-79:49:06.0 |
HIP 100416 |
18.51 |
| 2026-06-06 00:00 |
20:16:30.51 |
-79:50:14.1 |
HIP 99511 |
18.97 |
| 2026-06-06 12:00 |
20:16:07.00 |
-79:51:21.6 |
HIP 99511 |
17.44 |
| 2026-06-07 00:00 |
20:15:43.15 |
-79:52:28.5 |
HIP 99511 |
15.91 |
| 2026-06-07 12:00 |
20:15:18.97 |
-79:53:34.8 |
HIP 99511 |
14.38 |
| 2026-06-08 00:00 |
20:14:54.45 |
-79:54:40.4 |
HIP 99511 |
12.85 |
| 2026-06-08 12:00 |
20:14:29.61 |
-79:55:45.5 |
HIP 99511 |
11.33 |
| 2026-06-09 00:00 |
20:14:04.44 |
-79:56:49.9 |
HIP 99511 |
9.80 |
| 2026-06-09 12:00 |
20:13:38.94 |
-79:57:53.7 |
HIP 99511 |
8.29 |
| 2026-06-10 00:00 |
20:13:13.11 |
-79:58:56.8 |
HIP 99511 |
6.78 |
| 2026-06-10 12:00 |
20:12:46.96 |
-79:59:59.3 |
HIP 99511 |
5.30 |
| 2026-06-11 00:00 |
20:12:20.49 |
-80:01:01.1 |
HIP 99511 |
3.87 |
| 2026-06-11 12:00 |
20:11:53.70 |
-80:02:02.3 |
HIP 99511 |
2.58 |
| 2026-06-12 00:00 |
20:11:26.59 |
-80:03:02.7 |
HIP 99511 |
1.77 |
| 2026-06-12 12:00 |
20:10:59.17 |
-80:04:02.4 |
HIP 99511 |
2.11 |
| 2026-06-13 00:00 |
20:10:31.43 |
-80:05:01.4 |
HIP 99511 |
3.25 |
| 2026-06-13 12:00 |
20:10:03.39 |
-80:05:59.8 |
HIP 99511 |
4.65 |
| 2026-06-14 00:00 |
20:09:35.03 |
-80:06:57.3 |
HIP 99511 |
6.12 |
| 2026-06-14 12:00 |
20:09:06.38 |
-80:07:54.2 |
HIP 99511 |
7.63 |
| 2026-06-15 00:00 |
20:08:37.42 |
-80:08:50.2 |
HIP 99511 |
9.15 |
| 2026-06-15 12:00 |
20:08:08.16 |
-80:09:45.6 |
HIP 99511 |
10.69 |
| 2026-06-16 00:00 |
20:07:38.61 |
-80:10:40.1 |
HIP 99511 |
12.23 |
| 2026-06-16 12:00 |
20:07:08.77 |
-80:11:33.9 |
HIP 99511 |
13.78 |
| 2026-06-17 00:00 |
20:06:38.64 |
-80:12:26.9 |
HIP 99511 |
15.33 |
| 2026-06-17 12:00 |
20:06:08.22 |
-80:13:19.1 |
HIP 99511 |
16.89 |
| 2026-06-18 00:00 |
20:05:37.53 |
-80:14:10.5 |
HIP 99511 |
18.44 |
| 2026-06-18 12:00 |
20:05:06.56 |
-80:15:01.0 |
HIP 99511 |
20.00 |
| 2026-06-19 00:00 |
20:04:35.31 |
-80:15:50.8 |
HIP 99075 |
20.92 |
| 2026-06-19 12:00 |
20:04:03.80 |
-80:16:39.7 |
HIP 99075 |
20.54 |
| 2026-06-20 00:00 |
20:03:32.02 |
-80:17:27.8 |
HIP 99075 |
20.28 |
| 2026-06-20 12:00 |
20:02:59.99 |
-80:18:15.1 |
HIP 99075 |
20.16 |
| 2026-06-21 00:00 |
20:02:27.69 |
-80:19:01.5 |
HIP 99075 |
20.17 |
| 2026-06-21 12:00 |
20:01:55.14 |
-80:19:47.0 |
HIP 99075 |
20.31 |
| 2026-06-22 00:00 |
20:01:22.35 |
-80:20:31.7 |
HIP 99075 |
20.58 |