| Parameter |
Value |
| Designation |
C/2020 H2 (Pruyne) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-04-27T14:08:36.116160Z |
| Orbit solution date (soln_date, UTC) |
2025-01-10T09:12:14Z |
| Obs used |
121 |
| NEO |
- |
| M1 |
18.900 |
| K1 |
22.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-05-25.0000000 |
| e |
0.99553868 |
| q (au) |
0.833616 |
| a (au) |
186.853978 |
| i (deg) |
125.044340 |
| Ω (om, deg) |
277.635070 |
| ω (w, deg) |
26.692025 |
| M (ma, deg) |
0.010577 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.971 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.971 |
| n |
6.000 |
| gf |
0.998 |
| gb |
-1.000 |
| k |
0.893 |
| 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 |
06:33:18.34 |
+21:16:33.4 |
HIP 31172 |
15.90 |
| 2026-07-29 12:00 |
06:33:23.77 |
+21:16:22.0 |
HIP 31172 |
17.01 |
| 2026-07-30 00:00 |
06:33:29.17 |
+21:16:10.6 |
HIP 31353 |
16.57 |
| 2026-07-30 12:00 |
06:33:34.54 |
+21:15:59.2 |
HIP 31353 |
15.68 |
| 2026-07-31 00:00 |
06:33:39.89 |
+21:15:47.8 |
HIP 31353 |
14.84 |
| 2026-07-31 12:00 |
06:33:45.22 |
+21:15:36.3 |
HIP 31353 |
14.08 |
| 2026-08-01 00:00 |
06:33:50.51 |
+21:15:24.9 |
HIP 31353 |
13.39 |
| 2026-08-01 12:00 |
06:33:55.78 |
+21:15:13.4 |
HIP 31353 |
12.78 |
| 2026-08-02 00:00 |
06:34:01.02 |
+21:15:02.0 |
HIP 31353 |
12.28 |
| 2026-08-02 12:00 |
06:34:06.23 |
+21:14:50.5 |
HIP 31353 |
11.89 |
| 2026-08-03 00:00 |
06:34:11.41 |
+21:14:39.0 |
HIP 31353 |
11.62 |
| 2026-08-03 12:00 |
06:34:16.57 |
+21:14:27.5 |
HIP 31353 |
11.48 |
| 2026-08-04 00:00 |
06:34:21.69 |
+21:14:16.0 |
HIP 31353 |
11.46 |
| 2026-08-04 12:00 |
06:34:26.79 |
+21:14:04.4 |
HIP 31353 |
11.57 |
| 2026-08-05 00:00 |
06:34:31.85 |
+21:13:52.9 |
HIP 31353 |
11.80 |
| 2026-08-05 12:00 |
06:34:36.89 |
+21:13:41.4 |
HIP 31353 |
12.15 |
| 2026-08-06 00:00 |
06:34:41.89 |
+21:13:29.8 |
HIP 31353 |
12.59 |
| 2026-08-06 12:00 |
06:34:46.87 |
+21:13:18.2 |
HIP 31353 |
13.13 |
| 2026-08-07 00:00 |
06:34:51.81 |
+21:13:06.7 |
HIP 31353 |
13.74 |
| 2026-08-07 12:00 |
06:34:56.72 |
+21:12:55.1 |
HIP 31353 |
14.42 |
| 2026-08-08 00:00 |
06:35:01.60 |
+21:12:43.5 |
HIP 31353 |
15.15 |
| 2026-08-08 12:00 |
06:35:06.44 |
+21:12:31.9 |
HIP 31353 |
15.93 |
| 2026-08-09 00:00 |
06:35:11.26 |
+21:12:20.4 |
HIP 31353 |
16.74 |
| 2026-08-09 12:00 |
06:35:16.04 |
+21:12:08.8 |
HIP 31353 |
17.59 |
| 2026-08-10 00:00 |
06:35:20.78 |
+21:11:57.2 |
HIP 31353 |
18.46 |
| 2026-08-10 12:00 |
06:35:25.49 |
+21:11:45.6 |
HIP 31483 |
18.61 |
| 2026-08-11 00:00 |
06:35:30.17 |
+21:11:34.0 |
HIP 31483 |
18.29 |
| 2026-08-11 12:00 |
06:35:34.81 |
+21:11:22.4 |
HIP 31483 |
18.04 |
| 2026-08-12 00:00 |
06:35:39.42 |
+21:11:10.8 |
HIP 31483 |
17.86 |
| 2026-08-12 12:00 |
06:35:43.99 |
+21:10:59.1 |
HIP 31483 |
17.73 |
| 2026-08-13 00:00 |
06:35:48.53 |
+21:10:47.5 |
HIP 31483 |
17.68 |
| 2026-08-13 12:00 |
06:35:53.03 |
+21:10:35.9 |
HIP 31483 |
17.68 |
| 2026-08-14 00:00 |
06:35:57.49 |
+21:10:24.3 |
HIP 31483 |
17.75 |
| 2026-08-14 12:00 |
06:36:01.92 |
+21:10:12.7 |
HIP 31483 |
17.88 |
| 2026-08-15 00:00 |
06:36:06.31 |
+21:10:01.1 |
HIP 31483 |
18.06 |
| 2026-08-15 12:00 |
06:36:10.66 |
+21:09:49.5 |
HIP 31483 |
18.30 |
| 2026-08-16 00:00 |
06:36:14.97 |
+21:09:37.9 |
HIP 31483 |
18.59 |
| 2026-08-16 12:00 |
06:36:19.25 |
+21:09:26.4 |
HIP 31483 |
18.93 |
| 2026-08-17 00:00 |
06:36:23.48 |
+21:09:14.8 |
HIP 31483 |
19.30 |
| 2026-08-17 12:00 |
06:36:27.68 |
+21:09:03.2 |
HIP 31483 |
19.72 |
| 2026-08-18 00:00 |
06:36:31.84 |
+21:08:51.6 |
HIP 31483 |
20.17 |
| 2026-08-18 12:00 |
06:36:35.95 |
+21:08:40.1 |
HIP 31483 |
20.66 |
| 2026-08-19 00:00 |
06:36:40.03 |
+21:08:28.5 |
HIP 31483 |
21.17 |