| 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
$$
M_a = (9.276 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.276 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.857 |
| k |
0.800 |
| 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) |
| 2026-09-20 00:00 |
08:35:39.97 |
+18:52:00.0 |
HIP 42247 |
16.13 |
| 2026-09-20 12:00 |
08:35:42.68 |
+18:51:35.4 |
HIP 42247 |
15.52 |
| 2026-09-21 00:00 |
08:35:45.33 |
+18:51:10.9 |
HIP 42247 |
14.94 |
| 2026-09-21 12:00 |
08:35:47.94 |
+18:50:46.6 |
HIP 42247 |
14.38 |
| 2026-09-22 00:00 |
08:35:50.49 |
+18:50:22.5 |
HIP 42247 |
13.86 |
| 2026-09-22 12:00 |
08:35:52.99 |
+18:49:58.6 |
HIP 42247 |
13.36 |
| 2026-09-23 00:00 |
08:35:55.44 |
+18:49:34.9 |
HIP 42247 |
12.89 |
| 2026-09-23 12:00 |
08:35:57.84 |
+18:49:11.3 |
HIP 42247 |
12.46 |
| 2026-09-24 00:00 |
08:36:00.19 |
+18:48:47.9 |
HIP 42247 |
12.06 |
| 2026-09-24 12:00 |
08:36:02.48 |
+18:48:24.8 |
HIP 42247 |
11.70 |
| 2026-09-25 00:00 |
08:36:04.72 |
+18:48:01.8 |
HIP 42247 |
11.38 |
| 2026-09-25 12:00 |
08:36:06.90 |
+18:47:38.9 |
HIP 42247 |
11.09 |
| 2026-09-26 00:00 |
08:36:09.03 |
+18:47:16.3 |
HIP 42247 |
10.84 |
| 2026-09-26 12:00 |
08:36:11.11 |
+18:46:53.9 |
HIP 42247 |
10.64 |
| 2026-09-27 00:00 |
08:36:13.13 |
+18:46:31.6 |
HIP 42247 |
10.47 |
| 2026-09-27 12:00 |
08:36:15.10 |
+18:46:09.6 |
HIP 42247 |
10.35 |
| 2026-09-28 00:00 |
08:36:17.01 |
+18:45:47.7 |
HIP 42247 |
10.26 |
| 2026-09-28 12:00 |
08:36:18.87 |
+18:45:26.1 |
HIP 42247 |
10.22 |
| 2026-09-29 00:00 |
08:36:20.67 |
+18:45:04.6 |
HIP 42247 |
10.21 |
| 2026-09-29 12:00 |
08:36:22.41 |
+18:44:43.3 |
HIP 42247 |
10.24 |
| 2026-09-30 00:00 |
08:36:24.10 |
+18:44:22.2 |
HIP 42247 |
10.30 |
| 2026-09-30 12:00 |
08:36:25.73 |
+18:44:01.3 |
HIP 42247 |
10.39 |
| 2026-10-01 00:00 |
08:36:27.30 |
+18:43:40.7 |
HIP 42247 |
10.51 |
| 2026-10-01 12:00 |
08:36:28.81 |
+18:43:20.2 |
HIP 42247 |
10.65 |
| 2026-10-02 00:00 |
08:36:30.27 |
+18:43:00.0 |
HIP 42247 |
10.82 |
| 2026-10-02 12:00 |
08:36:31.67 |
+18:42:39.9 |
HIP 42247 |
11.01 |
| 2026-10-03 00:00 |
08:36:33.00 |
+18:42:20.0 |
HIP 42247 |
11.22 |
| 2026-10-03 12:00 |
08:36:34.28 |
+18:42:00.3 |
HIP 42247 |
11.44 |
| 2026-10-04 00:00 |
08:36:35.50 |
+18:41:40.9 |
HIP 42247 |
11.67 |
| 2026-10-04 12:00 |
08:36:36.66 |
+18:41:21.6 |
HIP 42247 |
11.92 |
| 2026-10-05 00:00 |
08:36:37.76 |
+18:41:02.6 |
HIP 42247 |
12.17 |
| 2026-10-05 12:00 |
08:36:38.80 |
+18:40:43.8 |
HIP 42247 |
12.43 |
| 2026-10-06 00:00 |
08:36:39.78 |
+18:40:25.2 |
HIP 42247 |
12.70 |
| 2026-10-06 12:00 |
08:36:40.69 |
+18:40:06.8 |
HIP 42247 |
12.97 |
| 2026-10-07 00:00 |
08:36:41.54 |
+18:39:48.7 |
HIP 42247 |
13.25 |
| 2026-10-07 12:00 |
08:36:42.33 |
+18:39:30.7 |
HIP 42247 |
13.53 |
| 2026-10-08 00:00 |
08:36:43.06 |
+18:39:13.0 |
HIP 42247 |
13.80 |
| 2026-10-08 12:00 |
08:36:43.73 |
+18:38:55.5 |
HIP 42247 |
14.08 |
| 2026-10-09 00:00 |
08:36:44.33 |
+18:38:38.2 |
HIP 42247 |
14.36 |
| 2026-10-09 12:00 |
08:36:44.87 |
+18:38:21.1 |
HIP 42247 |
14.64 |
| 2026-10-10 00:00 |
08:36:45.34 |
+18:38:04.3 |
HIP 42247 |
14.91 |
| 2026-10-10 12:00 |
08:36:45.75 |
+18:37:47.7 |
HIP 42247 |
15.18 |
| 2026-10-11 00:00 |
08:36:46.10 |
+18:37:31.3 |
HIP 42247 |
15.45 |