| 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) |
| 2026-07-29 00:00 |
19:15:51.83 |
-80:30:08.6 |
HIP 94158 |
16.06 |
| 2026-07-29 12:00 |
19:15:16.71 |
-80:29:38.3 |
HIP 94158 |
14.53 |
| 2026-07-30 00:00 |
19:14:41.80 |
-80:29:07.0 |
HIP 94158 |
13.00 |
| 2026-07-30 12:00 |
19:14:07.09 |
-80:28:34.8 |
HIP 94158 |
11.48 |
| 2026-07-31 00:00 |
19:13:32.58 |
-80:28:01.7 |
HIP 94158 |
9.95 |
| 2026-07-31 12:00 |
19:12:58.30 |
-80:27:27.6 |
HIP 94158 |
8.43 |
| 2026-08-01 00:00 |
19:12:24.23 |
-80:26:52.6 |
HIP 94158 |
6.91 |
| 2026-08-01 12:00 |
19:11:50.39 |
-80:26:16.6 |
HIP 94158 |
5.39 |
| 2026-08-02 00:00 |
19:11:16.77 |
-80:25:39.8 |
HIP 94158 |
3.89 |
| 2026-08-02 12:00 |
19:10:43.39 |
-80:25:02.0 |
HIP 94158 |
2.40 |
| 2026-08-03 00:00 |
19:10:10.25 |
-80:24:23.3 |
HIP 94158 |
1.02 |
| 2026-08-03 12:00 |
19:09:37.35 |
-80:23:43.7 |
HIP 94158 |
0.98 |
| 2026-08-04 00:00 |
19:09:04.69 |
-80:23:03.2 |
HIP 94158 |
2.34 |
| 2026-08-04 12:00 |
19:08:32.29 |
-80:22:21.9 |
HIP 94158 |
3.82 |
| 2026-08-05 00:00 |
19:08:00.14 |
-80:21:39.6 |
HIP 94158 |
5.32 |
| 2026-08-05 12:00 |
19:07:28.25 |
-80:20:56.5 |
HIP 94158 |
6.82 |
| 2026-08-06 00:00 |
19:06:56.62 |
-80:20:12.5 |
HIP 94158 |
8.33 |
| 2026-08-06 12:00 |
19:06:25.25 |
-80:19:27.7 |
HIP 94158 |
9.84 |
| 2026-08-07 00:00 |
19:05:54.16 |
-80:18:42.0 |
HIP 94158 |
11.34 |
| 2026-08-07 12:00 |
19:05:23.34 |
-80:17:55.4 |
HIP 94158 |
12.85 |
| 2026-08-08 00:00 |
19:04:52.80 |
-80:17:08.0 |
HIP 94158 |
14.35 |
| 2026-08-08 12:00 |
19:04:22.55 |
-80:16:19.8 |
HIP 94158 |
15.86 |
| 2026-08-09 00:00 |
19:03:52.57 |
-80:15:30.7 |
HIP 94158 |
17.36 |
| 2026-08-09 12:00 |
19:03:22.89 |
-80:14:40.8 |
HIP 94158 |
18.86 |
| 2026-08-10 00:00 |
19:02:53.50 |
-80:13:50.1 |
HIP 92877 |
19.17 |
| 2026-08-10 12:00 |
19:02:24.41 |
-80:12:58.6 |
HIP 92877 |
17.83 |
| 2026-08-11 00:00 |
19:01:55.61 |
-80:12:06.4 |
HIP 92877 |
16.53 |
| 2026-08-11 12:00 |
19:01:27.12 |
-80:11:13.3 |
HIP 92877 |
15.27 |
| 2026-08-12 00:00 |
19:00:58.93 |
-80:10:19.4 |
HIP 92877 |
14.08 |
| 2026-08-12 12:00 |
19:00:31.06 |
-80:09:24.8 |
HIP 92877 |
12.96 |
| 2026-08-13 00:00 |
19:00:03.49 |
-80:08:29.4 |
HIP 92877 |
11.93 |
| 2026-08-13 12:00 |
18:59:36.24 |
-80:07:33.3 |
HIP 92877 |
11.02 |
| 2026-08-14 00:00 |
18:59:09.30 |
-80:06:36.4 |
HIP 92877 |
10.27 |
| 2026-08-14 12:00 |
18:58:42.69 |
-80:05:38.7 |
HIP 92877 |
9.70 |
| 2026-08-15 00:00 |
18:58:16.39 |
-80:04:40.4 |
HIP 92877 |
9.36 |
| 2026-08-15 12:00 |
18:57:50.42 |
-80:03:41.3 |
HIP 92877 |
9.26 |
| 2026-08-16 00:00 |
18:57:24.78 |
-80:02:41.5 |
HIP 92877 |
9.41 |
| 2026-08-16 12:00 |
18:56:59.46 |
-80:01:41.1 |
HIP 92877 |
9.80 |
| 2026-08-17 00:00 |
18:56:34.48 |
-80:00:39.9 |
HIP 92877 |
10.41 |
| 2026-08-17 12:00 |
18:56:09.82 |
-79:59:38.0 |
HIP 92877 |
11.19 |
| 2026-08-18 00:00 |
18:55:45.50 |
-79:58:35.5 |
HIP 92877 |
12.11 |
| 2026-08-18 12:00 |
18:55:21.51 |
-79:57:32.3 |
HIP 92877 |
13.15 |
| 2026-08-19 00:00 |
18:54:57.87 |
-79:56:28.5 |
HIP 92877 |
14.27 |