| Parameter |
Value |
| Designation |
P/2020 S1 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-01-16T21:13:40.255680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:34:12Z |
| Obs used |
33 |
| NEO |
- |
| M1 |
17.500 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-09-16T09:59:30.048000Z |
| Discovery magnitude (MPC) |
21.70 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-09-10.0000000 |
| e |
0.50722330 |
| q (au) |
2.947362 |
| a (au) |
5.981132 |
| i (deg) |
13.733881 |
| Ω (om, deg) |
129.458525 |
| ω (w, deg) |
254.866187 |
| M (ma, deg) |
351.315802 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.347 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.347 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.905 |
| k |
1.000 |
| 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) |
| 2026-05-12 00:00 |
12:14:58.30 |
+11:41:40.1 |
HIP 59683 |
11.82 |
| 2026-05-12 12:00 |
12:14:52.45 |
+11:41:47.1 |
HIP 59683 |
10.67 |
| 2026-05-13 00:00 |
12:14:46.69 |
+11:41:53.4 |
HIP 59683 |
9.63 |
| 2026-05-13 12:00 |
12:14:41.02 |
+11:41:58.8 |
HIP 59683 |
8.71 |
| 2026-05-14 00:00 |
12:14:35.46 |
+11:42:03.3 |
HIP 59683 |
7.95 |
| 2026-05-14 12:00 |
12:14:29.99 |
+11:42:07.0 |
HIP 59683 |
7.39 |
| 2026-05-15 00:00 |
12:14:24.62 |
+11:42:09.8 |
HIP 59683 |
7.07 |
| 2026-05-15 12:00 |
12:14:19.36 |
+11:42:11.8 |
HIP 59683 |
6.99 |
| 2026-05-16 00:00 |
12:14:14.19 |
+11:42:12.9 |
HIP 59683 |
7.15 |
| 2026-05-16 12:00 |
12:14:09.12 |
+11:42:13.2 |
HIP 59683 |
7.53 |
| 2026-05-17 00:00 |
12:14:04.16 |
+11:42:12.6 |
HIP 59683 |
8.09 |
| 2026-05-17 12:00 |
12:13:59.30 |
+11:42:11.2 |
HIP 59683 |
8.77 |
| 2026-05-18 00:00 |
12:13:54.54 |
+11:42:09.0 |
HIP 59683 |
9.55 |
| 2026-05-18 12:00 |
12:13:49.88 |
+11:42:05.9 |
HIP 59683 |
10.39 |
| 2026-05-19 00:00 |
12:13:45.32 |
+11:42:02.0 |
HIP 59683 |
11.27 |
| 2026-05-19 12:00 |
12:13:40.87 |
+11:41:57.2 |
HIP 59683 |
12.18 |
| 2026-05-20 00:00 |
12:13:36.53 |
+11:41:51.7 |
HIP 59592 |
12.19 |
| 2026-05-20 12:00 |
12:13:32.28 |
+11:41:45.2 |
HIP 59592 |
11.66 |
| 2026-05-21 00:00 |
12:13:28.14 |
+11:41:38.0 |
HIP 59592 |
11.20 |
| 2026-05-21 12:00 |
12:13:24.11 |
+11:41:29.9 |
HIP 59592 |
10.80 |
| 2026-05-22 00:00 |
12:13:20.18 |
+11:41:21.1 |
HIP 59592 |
10.48 |
| 2026-05-22 12:00 |
12:13:16.35 |
+11:41:11.4 |
HIP 59592 |
10.22 |
| 2026-05-23 00:00 |
12:13:12.64 |
+11:41:00.8 |
HIP 59592 |
10.04 |
| 2026-05-23 12:00 |
12:13:09.02 |
+11:40:49.5 |
HIP 59592 |
9.92 |
| 2026-05-24 00:00 |
12:13:05.51 |
+11:40:37.4 |
HIP 59592 |
9.87 |
| 2026-05-24 12:00 |
12:13:02.11 |
+11:40:24.5 |
HIP 59592 |
9.87 |
| 2026-05-25 00:00 |
12:12:58.81 |
+11:40:10.7 |
HIP 59592 |
9.93 |
| 2026-05-25 12:00 |
12:12:55.62 |
+11:39:56.2 |
HIP 59592 |
10.03 |
| 2026-05-26 00:00 |
12:12:52.54 |
+11:39:40.9 |
HIP 59592 |
10.18 |
| 2026-05-26 12:00 |
12:12:49.56 |
+11:39:24.8 |
HIP 59592 |
10.35 |
| 2026-05-27 00:00 |
12:12:46.68 |
+11:39:07.9 |
HIP 59592 |
10.56 |
| 2026-05-27 12:00 |
12:12:43.92 |
+11:38:50.2 |
HIP 59592 |
10.78 |
| 2026-05-28 00:00 |
12:12:41.26 |
+11:38:31.8 |
HIP 59592 |
11.03 |
| 2026-05-28 12:00 |
12:12:38.71 |
+11:38:12.5 |
HIP 59592 |
11.28 |
| 2026-05-29 00:00 |
12:12:36.26 |
+11:37:52.5 |
HIP 59592 |
11.55 |
| 2026-05-29 12:00 |
12:12:33.92 |
+11:37:31.8 |
HIP 59592 |
11.82 |
| 2026-05-30 00:00 |
12:12:31.69 |
+11:37:10.2 |
HIP 59592 |
12.09 |
| 2026-05-30 12:00 |
12:12:29.56 |
+11:36:47.9 |
HIP 59592 |
12.36 |
| 2026-05-31 00:00 |
12:12:27.54 |
+11:36:24.9 |
HIP 59592 |
12.63 |
| 2026-05-31 12:00 |
12:12:25.63 |
+11:36:01.1 |
HIP 59592 |
12.89 |
| 2026-06-01 00:00 |
12:12:23.82 |
+11:35:36.5 |
HIP 59592 |
13.15 |
| 2026-06-01 12:00 |
12:12:22.12 |
+11:35:11.2 |
HIP 59592 |
13.40 |
| 2026-06-02 00:00 |
12:12:20.53 |
+11:34:45.1 |
HIP 59592 |
13.65 |