C/2020 B2 (Lemmon)
| 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) |
| 2026-02-03 00:00 |
19:35:02.90 |
-75:27:40.3 |
HIP 96564 |
11.12 |
| 2026-02-03 12:00 |
19:35:33.57 |
-75:27:57.3 |
HIP 96564 |
9.40 |
| 2026-02-04 00:00 |
19:36:04.17 |
-75:28:14.9 |
HIP 96564 |
7.79 |
| 2026-02-04 12:00 |
19:36:34.70 |
-75:28:33.0 |
HIP 96564 |
6.38 |
| 2026-02-05 00:00 |
19:37:05.14 |
-75:28:51.6 |
HIP 96564 |
5.33 |
| 2026-02-05 12:00 |
19:37:35.51 |
-75:29:10.7 |
HIP 96564 |
4.87 |
| 2026-02-06 00:00 |
19:38:05.81 |
-75:29:30.3 |
HIP 96564 |
5.16 |
| 2026-02-06 12:00 |
19:38:36.02 |
-75:29:50.4 |
HIP 96564 |
6.08 |
| 2026-02-07 00:00 |
19:39:06.16 |
-75:30:11.1 |
HIP 96564 |
7.41 |
| 2026-02-07 12:00 |
19:39:36.22 |
-75:30:32.2 |
HIP 96564 |
8.95 |
| 2026-02-08 00:00 |
19:40:06.19 |
-75:30:53.9 |
HIP 96564 |
10.62 |
| 2026-02-08 12:00 |
19:40:36.08 |
-75:31:16.1 |
HIP 97008 |
11.68 |
| 2026-02-09 00:00 |
19:41:05.89 |
-75:31:38.8 |
HIP 97008 |
10.58 |
| 2026-02-09 12:00 |
19:41:35.62 |
-75:32:02.0 |
HIP 97008 |
9.74 |
| 2026-02-10 00:00 |
19:42:05.26 |
-75:32:25.7 |
HIP 97008 |
9.23 |
| 2026-02-10 12:00 |
19:42:34.81 |
-75:32:49.9 |
HIP 97008 |
9.10 |
| 2026-02-11 00:00 |
19:43:04.28 |
-75:33:14.6 |
HIP 97008 |
9.38 |
| 2026-02-11 12:00 |
19:43:33.66 |
-75:33:39.9 |
HIP 97008 |
10.02 |
| 2026-02-12 00:00 |
19:44:02.95 |
-75:34:05.7 |
HIP 97008 |
10.96 |
| 2026-02-12 12:00 |
19:44:32.15 |
-75:34:32.0 |
HIP 97008 |
12.12 |
| 2026-02-13 00:00 |
19:45:01.26 |
-75:34:58.8 |
HIP 97008 |
13.45 |
| 2026-02-13 12:00 |
19:45:30.27 |
-75:35:26.1 |
HIP 97008 |
14.90 |
| 2026-02-14 00:00 |
19:45:59.20 |
-75:35:53.9 |
HIP 97008 |
16.44 |
| 2026-02-14 12:00 |
19:46:28.03 |
-75:36:22.3 |
HIP 97008 |
18.04 |
| 2026-02-15 00:00 |
19:46:56.76 |
-75:36:51.2 |
HIP 97008 |
19.69 |
| 2026-02-15 12:00 |
19:47:25.39 |
-75:37:20.6 |
HIP 97008 |
21.37 |
| 2026-02-16 00:00 |
19:47:53.93 |
-75:37:50.5 |
HIP 97008 |
23.08 |
| 2026-02-16 12:00 |
19:48:22.37 |
-75:38:20.9 |
HIP 97008 |
24.81 |
| 2026-02-17 00:00 |
19:48:50.71 |
-75:38:51.8 |
HIP 97008 |
26.55 |
| 2026-02-17 12:00 |
19:49:18.95 |
-75:39:23.3 |
HIP 97008 |
28.30 |
| 2026-02-18 00:00 |
19:49:47.08 |
-75:39:55.2 |
HIP 97623 |
29.18 |
| 2026-02-18 12:00 |
19:50:15.11 |
-75:40:27.7 |
HIP 97623 |
29.61 |
| 2026-02-19 00:00 |
19:50:43.04 |
-75:41:00.7 |
HIP 97623 |
30.15 |
| 2026-02-19 12:00 |
19:51:10.86 |
-75:41:34.2 |
HIP 97838 |
29.85 |
| 2026-02-20 00:00 |
19:51:38.58 |
-75:42:08.3 |
HIP 97838 |
28.98 |
| 2026-02-20 12:00 |
19:52:06.18 |
-75:42:42.8 |
HIP 97838 |
28.19 |
| 2026-02-21 00:00 |
19:52:33.68 |
-75:43:17.8 |
HIP 97838 |
27.49 |
| 2026-02-21 12:00 |
19:53:01.07 |
-75:43:53.4 |
HIP 97838 |
26.88 |
| 2026-02-22 00:00 |
19:53:28.35 |
-75:44:29.5 |
HIP 97838 |
26.36 |
| 2026-02-22 12:00 |
19:53:55.51 |
-75:45:06.1 |
HIP 97838 |
25.94 |
| 2026-02-23 00:00 |
19:54:22.56 |
-75:45:43.1 |
HIP 97838 |
25.62 |
| 2026-02-23 12:00 |
19:54:49.50 |
-75:46:20.7 |
HIP 97838 |
25.42 |
| 2026-02-24 00:00 |
19:55:16.32 |
-75:46:58.8 |
HIP 97838 |
25.32 |