| Parameter |
Value |
| Designation |
C/2020 H11 (PANSTARRS-Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-09-15T11:27:22.633920Z |
| Orbit solution date (soln_date, UTC) |
2023-04-28T15:42:08Z |
| Obs used |
53 |
| NEO |
- |
| M1 |
7.400 |
| K1 |
11.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-04-21T13:41:56.256000Z |
| Discovery magnitude (MPC) |
22.10 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-03-26.0000000 |
| e |
0.99927122 |
| q (au) |
7.631184 |
| a (au) |
10471.148612 |
| i (deg) |
151.414831 |
| Ω (om, deg) |
303.005797 |
| ω (w, deg) |
91.488781 |
| M (ma, deg) |
359.999840 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.273 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.273 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.857 |
| k |
0.800 |
| δ90 |
9.778 |
| 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) |
| 2026-03-26 00:00 |
08:22:03.29 |
+21:22:22.3 |
HIP 40950 |
33.21 |
| 2026-03-26 12:00 |
08:21:56.47 |
+21:22:22.8 |
HIP 40950 |
32.85 |
| 2026-03-27 00:00 |
08:21:49.73 |
+21:22:23.1 |
HIP 40950 |
32.57 |
| 2026-03-27 12:00 |
08:21:43.08 |
+21:22:23.2 |
HIP 40950 |
32.37 |
| 2026-03-28 00:00 |
08:21:36.50 |
+21:22:22.9 |
HIP 40781 |
31.64 |
| 2026-03-28 12:00 |
08:21:30.00 |
+21:22:22.4 |
HIP 40781 |
30.16 |
| 2026-03-29 00:00 |
08:21:23.59 |
+21:22:21.6 |
HIP 40781 |
28.70 |
| 2026-03-29 12:00 |
08:21:17.25 |
+21:22:20.6 |
HIP 40781 |
27.27 |
| 2026-03-30 00:00 |
08:21:11.00 |
+21:22:19.3 |
HIP 40781 |
25.86 |
| 2026-03-30 12:00 |
08:21:04.83 |
+21:22:17.7 |
HIP 40781 |
24.47 |
| 2026-03-31 00:00 |
08:20:58.73 |
+21:22:15.9 |
HIP 40781 |
23.10 |
| 2026-03-31 12:00 |
08:20:52.72 |
+21:22:13.8 |
HIP 40781 |
21.76 |
| 2026-04-01 00:00 |
08:20:46.79 |
+21:22:11.5 |
HIP 40781 |
20.43 |
| 2026-04-01 12:00 |
08:20:40.94 |
+21:22:08.8 |
HIP 40781 |
19.14 |
| 2026-04-02 00:00 |
08:20:35.17 |
+21:22:06.0 |
HIP 40781 |
17.87 |
| 2026-04-02 12:00 |
08:20:29.49 |
+21:22:02.8 |
HIP 40781 |
16.63 |
| 2026-04-03 00:00 |
08:20:23.88 |
+21:21:59.5 |
HIP 40781 |
15.41 |
| 2026-04-03 12:00 |
08:20:18.36 |
+21:21:55.8 |
HIP 40781 |
14.23 |
| 2026-04-04 00:00 |
08:20:12.91 |
+21:21:51.9 |
HIP 40781 |
13.08 |
| 2026-04-04 12:00 |
08:20:07.55 |
+21:21:47.8 |
HIP 40781 |
11.98 |
| 2026-04-05 00:00 |
08:20:02.27 |
+21:21:43.4 |
HIP 40781 |
10.91 |
| 2026-04-05 12:00 |
08:19:57.08 |
+21:21:38.7 |
HIP 40781 |
9.90 |
| 2026-04-06 00:00 |
08:19:51.96 |
+21:21:33.8 |
HIP 40781 |
8.94 |
| 2026-04-06 12:00 |
08:19:46.93 |
+21:21:28.6 |
HIP 40781 |
8.06 |
| 2026-04-07 00:00 |
08:19:41.97 |
+21:21:23.2 |
HIP 40781 |
7.28 |
| 2026-04-07 12:00 |
08:19:37.10 |
+21:21:17.5 |
HIP 40781 |
6.60 |
| 2026-04-08 00:00 |
08:19:32.31 |
+21:21:11.6 |
HIP 40781 |
6.07 |
| 2026-04-08 12:00 |
08:19:27.60 |
+21:21:05.4 |
HIP 40781 |
5.71 |
| 2026-04-09 00:00 |
08:19:22.98 |
+21:20:59.0 |
HIP 40781 |
5.55 |
| 2026-04-09 12:00 |
08:19:18.43 |
+21:20:52.3 |
HIP 40781 |
5.59 |
| 2026-04-10 00:00 |
08:19:13.97 |
+21:20:45.4 |
HIP 40781 |
5.81 |
| 2026-04-10 12:00 |
08:19:09.59 |
+21:20:38.3 |
HIP 40781 |
6.19 |
| 2026-04-11 00:00 |
08:19:05.29 |
+21:20:30.9 |
HIP 40781 |
6.69 |
| 2026-04-11 12:00 |
08:19:01.07 |
+21:20:23.2 |
HIP 40781 |
7.28 |
| 2026-04-12 00:00 |
08:18:56.94 |
+21:20:15.3 |
HIP 40781 |
7.93 |
| 2026-04-12 12:00 |
08:18:52.88 |
+21:20:07.2 |
HIP 40781 |
8.62 |
| 2026-04-13 00:00 |
08:18:48.91 |
+21:19:58.8 |
HIP 40781 |
9.35 |
| 2026-04-13 12:00 |
08:18:45.02 |
+21:19:50.1 |
HIP 40781 |
10.08 |
| 2026-04-14 00:00 |
08:18:41.21 |
+21:19:41.3 |
HIP 40781 |
10.83 |
| 2026-04-14 12:00 |
08:18:37.49 |
+21:19:32.2 |
HIP 40781 |
11.58 |
| 2026-04-15 00:00 |
08:18:33.84 |
+21:19:22.8 |
HIP 40781 |
12.33 |
| 2026-04-15 12:00 |
08:18:30.27 |
+21:19:13.2 |
HIP 40650 |
12.30 |
| 2026-04-16 00:00 |
08:18:26.79 |
+21:19:03.4 |
HIP 40650 |
11.62 |