| Parameter |
Value |
| Designation |
C/2020 S2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-12-21T22:27:29.819520Z |
| Orbit solution date (soln_date, UTC) |
2022-09-27T15:42:34Z |
| Obs used |
96 |
| NEO |
- |
| M1 |
16.300 |
| K1 |
13.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-09-16T07:49:20.697600Z |
| Discovery magnitude (MPC) |
20.75 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-10-15.0000000 |
| e |
0.82748820 |
| q (au) |
1.756056 |
| a (au) |
10.179340 |
| i (deg) |
22.397832 |
| Ω (om, deg) |
197.685362 |
| ω (w, deg) |
202.263038 |
| M (ma, deg) |
357.938311 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.508 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.508 |
| n |
6.000 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
1.000 |
| 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 |
12:36:57.50 |
-05:16:12.7 |
HIP 61687 |
26.75 |
| 2026-07-29 12:00 |
12:37:02.51 |
-05:16:34.1 |
HIP 61687 |
25.47 |
| 2026-07-30 00:00 |
12:37:07.57 |
-05:16:55.9 |
HIP 61687 |
24.18 |
| 2026-07-30 12:00 |
12:37:12.69 |
-05:17:18.0 |
HIP 61687 |
22.87 |
| 2026-07-31 00:00 |
12:37:17.86 |
-05:17:40.5 |
HIP 61687 |
21.55 |
| 2026-07-31 12:00 |
12:37:23.09 |
-05:18:03.4 |
HIP 61687 |
20.22 |
| 2026-08-01 00:00 |
12:37:28.37 |
-05:18:26.6 |
HIP 61687 |
18.88 |
| 2026-08-01 12:00 |
12:37:33.71 |
-05:18:50.2 |
HIP 61687 |
17.54 |
| 2026-08-02 00:00 |
12:37:39.10 |
-05:19:14.2 |
HIP 61687 |
16.18 |
| 2026-08-02 12:00 |
12:37:44.54 |
-05:19:38.5 |
HIP 61687 |
14.82 |
| 2026-08-03 00:00 |
12:37:50.03 |
-05:20:03.1 |
HIP 61687 |
13.46 |
| 2026-08-03 12:00 |
12:37:55.58 |
-05:20:28.2 |
HIP 61687 |
12.10 |
| 2026-08-04 00:00 |
12:38:01.18 |
-05:20:53.6 |
HIP 61687 |
10.75 |
| 2026-08-04 12:00 |
12:38:06.83 |
-05:21:19.3 |
HIP 61687 |
9.42 |
| 2026-08-05 00:00 |
12:38:12.53 |
-05:21:45.4 |
HIP 61687 |
8.13 |
| 2026-08-05 12:00 |
12:38:18.28 |
-05:22:11.8 |
HIP 61687 |
6.91 |
| 2026-08-06 00:00 |
12:38:24.09 |
-05:22:38.6 |
HIP 61687 |
5.81 |
| 2026-08-06 12:00 |
12:38:29.94 |
-05:23:05.7 |
HIP 61687 |
4.93 |
| 2026-08-07 00:00 |
12:38:35.85 |
-05:23:33.2 |
HIP 61687 |
4.41 |
| 2026-08-07 12:00 |
12:38:41.80 |
-05:24:01.0 |
HIP 61687 |
4.41 |
| 2026-08-08 00:00 |
12:38:47.81 |
-05:24:29.2 |
HIP 61687 |
4.93 |
| 2026-08-08 12:00 |
12:38:53.86 |
-05:24:57.7 |
HIP 61687 |
5.85 |
| 2026-08-09 00:00 |
12:38:59.97 |
-05:25:26.5 |
HIP 61687 |
7.02 |
| 2026-08-09 12:00 |
12:39:06.12 |
-05:25:55.7 |
HIP 61687 |
8.34 |
| 2026-08-10 00:00 |
12:39:12.32 |
-05:26:25.1 |
HIP 61687 |
9.76 |
| 2026-08-10 12:00 |
12:39:18.57 |
-05:26:55.0 |
HIP 61687 |
11.25 |
| 2026-08-11 00:00 |
12:39:24.86 |
-05:27:25.1 |
HIP 61687 |
12.78 |
| 2026-08-11 12:00 |
12:39:31.21 |
-05:27:55.5 |
HIP 61687 |
14.36 |
| 2026-08-12 00:00 |
12:39:37.60 |
-05:28:26.3 |
HIP 61687 |
15.96 |
| 2026-08-12 12:00 |
12:39:44.03 |
-05:28:57.4 |
HIP 61687 |
17.59 |
| 2026-08-13 00:00 |
12:39:50.51 |
-05:29:28.8 |
HIP 61687 |
19.24 |
| 2026-08-13 12:00 |
12:39:57.04 |
-05:30:00.6 |
HIP 61687 |
20.91 |
| 2026-08-14 00:00 |
12:40:03.62 |
-05:30:32.6 |
HIP 61687 |
22.60 |
| 2026-08-14 12:00 |
12:40:10.23 |
-05:31:04.9 |
HIP 61687 |
24.30 |
| 2026-08-15 00:00 |
12:40:16.90 |
-05:31:37.6 |
HIP 61687 |
26.02 |
| 2026-08-15 12:00 |
12:40:23.60 |
-05:32:10.5 |
HIP 61687 |
27.76 |
| 2026-08-16 00:00 |
12:40:30.35 |
-05:32:43.7 |
HIP 61687 |
29.51 |
| 2026-08-16 12:00 |
12:40:37.15 |
-05:33:17.3 |
HIP 61971 |
28.68 |
| 2026-08-17 00:00 |
12:40:43.98 |
-05:33:51.1 |
HIP 61971 |
27.91 |
| 2026-08-17 12:00 |
12:40:50.86 |
-05:34:25.2 |
HIP 62013 |
26.89 |
| 2026-08-18 00:00 |
12:40:57.78 |
-05:34:59.6 |
HIP 62013 |
25.37 |
| 2026-08-18 12:00 |
12:41:04.74 |
-05:35:34.3 |
HIP 62013 |
23.88 |
| 2026-08-19 00:00 |
12:41:11.75 |
-05:36:09.3 |
HIP 62013 |
22.44 |