| Parameter |
Value |
| Designation |
C/2020 H7 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-06-03T12:09:27.060480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:34:06Z |
| Obs used |
174 |
| NEO |
- |
| M1 |
11.200 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-04-29T10:09:34.848000Z |
| Discovery magnitude (MPC) |
20.60 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-05-21.0000000 |
| e |
0.99942724 |
| q (au) |
4.420107 |
| a (au) |
7717.249417 |
| i (deg) |
135.922901 |
| Ω (om, deg) |
323.529129 |
| ω (w, deg) |
82.769160 |
| M (ma, deg) |
359.999980 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.096 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.096 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.784 |
| k |
0.800 |
| δ90 |
9.996 |
| 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 |
08:26:41.44 |
+06:55:21.3 |
HIP 41430 |
18.50 |
| 2026-06-01 12:00 |
08:26:44.46 |
+06:55:14.5 |
HIP 41430 |
18.44 |
| 2026-06-02 00:00 |
08:26:47.52 |
+06:55:07.5 |
HIP 41430 |
18.41 |
| 2026-06-02 12:00 |
08:26:50.63 |
+06:55:00.2 |
HIP 41430 |
18.41 |
| 2026-06-03 00:00 |
08:26:53.78 |
+06:54:52.6 |
HIP 41430 |
18.46 |
| 2026-06-03 12:00 |
08:26:56.98 |
+06:54:44.8 |
HIP 41430 |
18.54 |
| 2026-06-04 00:00 |
08:27:00.22 |
+06:54:36.6 |
HIP 41430 |
18.66 |
| 2026-06-04 12:00 |
08:27:03.51 |
+06:54:28.2 |
HIP 41430 |
18.82 |
| 2026-06-05 00:00 |
08:27:06.83 |
+06:54:19.5 |
HIP 41430 |
19.02 |
| 2026-06-05 12:00 |
08:27:10.21 |
+06:54:10.5 |
HIP 41430 |
19.26 |
| 2026-06-06 00:00 |
08:27:13.62 |
+06:54:01.2 |
HIP 41430 |
19.54 |
| 2026-06-06 12:00 |
08:27:17.07 |
+06:53:51.6 |
HIP 41569 |
19.30 |
| 2026-06-07 00:00 |
08:27:20.57 |
+06:53:41.8 |
HIP 41569 |
18.49 |
| 2026-06-07 12:00 |
08:27:24.11 |
+06:53:31.7 |
HIP 41569 |
17.68 |
| 2026-06-08 00:00 |
08:27:27.69 |
+06:53:21.2 |
HIP 41569 |
16.87 |
| 2026-06-08 12:00 |
08:27:31.31 |
+06:53:10.6 |
HIP 41569 |
16.05 |
| 2026-06-09 00:00 |
08:27:34.97 |
+06:52:59.6 |
HIP 41569 |
15.25 |
| 2026-06-09 12:00 |
08:27:38.67 |
+06:52:48.3 |
HIP 41569 |
14.44 |
| 2026-06-10 00:00 |
08:27:42.41 |
+06:52:36.8 |
HIP 41569 |
13.65 |
| 2026-06-10 12:00 |
08:27:46.19 |
+06:52:25.0 |
HIP 41569 |
12.88 |
| 2026-06-11 00:00 |
08:27:50.01 |
+06:52:12.9 |
HIP 41569 |
12.12 |
| 2026-06-11 12:00 |
08:27:53.87 |
+06:52:00.5 |
HIP 41569 |
11.39 |
| 2026-06-12 00:00 |
08:27:57.76 |
+06:51:47.9 |
HIP 41569 |
10.69 |
| 2026-06-12 12:00 |
08:28:01.69 |
+06:51:34.9 |
HIP 41569 |
10.04 |
| 2026-06-13 00:00 |
08:28:05.66 |
+06:51:21.7 |
HIP 41569 |
9.45 |
| 2026-06-13 12:00 |
08:28:09.67 |
+06:51:08.2 |
HIP 41569 |
8.93 |
| 2026-06-14 00:00 |
08:28:13.71 |
+06:50:54.4 |
HIP 41569 |
8.50 |
| 2026-06-14 12:00 |
08:28:17.79 |
+06:50:40.4 |
HIP 41569 |
8.17 |
| 2026-06-15 00:00 |
08:28:21.91 |
+06:50:26.0 |
HIP 41569 |
7.97 |
| 2026-06-15 12:00 |
08:28:26.06 |
+06:50:11.4 |
HIP 41569 |
7.91 |
| 2026-06-16 00:00 |
08:28:30.25 |
+06:49:56.6 |
HIP 41569 |
7.99 |
| 2026-06-16 12:00 |
08:28:34.47 |
+06:49:41.4 |
HIP 41569 |
8.22 |
| 2026-06-17 00:00 |
08:28:38.72 |
+06:49:26.0 |
HIP 41550 |
8.57 |
| 2026-06-17 12:00 |
08:28:43.01 |
+06:49:10.2 |
HIP 41550 |
8.94 |
| 2026-06-18 00:00 |
08:28:47.33 |
+06:48:54.3 |
HIP 41550 |
9.43 |
| 2026-06-18 12:00 |
08:28:51.68 |
+06:48:38.0 |
HIP 41550 |
10.02 |
| 2026-06-19 00:00 |
08:28:56.06 |
+06:48:21.5 |
HIP 41550 |
10.70 |
| 2026-06-19 12:00 |
08:29:00.48 |
+06:48:04.7 |
HIP 41550 |
11.46 |
| 2026-06-20 00:00 |
08:29:04.93 |
+06:47:47.6 |
HIP 41550 |
12.27 |
| 2026-06-20 12:00 |
08:29:09.41 |
+06:47:30.3 |
HIP 41550 |
13.14 |
| 2026-06-21 00:00 |
08:29:13.92 |
+06:47:12.6 |
HIP 41550 |
14.06 |
| 2026-06-21 12:00 |
08:29:18.45 |
+06:46:54.8 |
HIP 41550 |
15.01 |
| 2026-06-22 00:00 |
08:29:23.02 |
+06:46:36.6 |
HIP 41550 |
16.00 |