P/2023 S1 (PANSTARRS)
Metadata
| Parameter | Value |
|---|---|
| Designation | P/2023 S1 (PANSTARRS) |
| Type | P |
| Perihelion (tp_cal, UTC) | 2025-02-24T01:28:44.201280Z |
| Orbit solution date (soln_date, UTC) | 2026-05-22T14:12:28Z |
| Obs used | 1928 |
| NEO | - |
| M1 | 10.300 |
| K1 | 11.500 |
| PC | 0.030 |
| Discovery observation (MPC, UTC) | 2023-09-20T14:30:23.443200Z |
| Discovery magnitude (MPC) | 20.36 w |
| Discovery observatory (MPC) | F52 · Pan-STARRS 2, Haleakala |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2024-10-31.0000000 |
| e | 0.31884323 |
| q (au) | 2.619726 |
| a (au) | 3.845996 |
| i (deg) | 9.156216 |
| Ω (om, deg) | 317.292570 |
| ω (w, deg) | 180.274180 |
| M (ma, deg) | 344.833705 |
Magnitude
Scatter + Global Linear
$$ M_a = (9.337 + 5.218\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 9.337 |
| n | 5.218 |
| gf | 0.883 |
| gb | -0.801 |
| k | 0.997 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) | End (UTC) | a | b |
|---|---|---|---|
| 2023-09-15 | 2025-02-24 | +2.2459 | -1.234 |
| 2025-02-24 | 2026-02-25 | +16.8467 | -7.135 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Finding Chart
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 14:46:44.04 | -26:15:17.1 | HIP 72357 | 16.93 |
| 2026-07-29 12:00 | 14:46:58.07 | -26:14:48.4 | HIP 72357 | 14.18 |
| 2026-07-30 00:00 | 14:47:12.33 | -26:14:20.8 | HIP 72357 | 11.65 |
| 2026-07-30 12:00 | 14:47:26.81 | -26:13:54.4 | HIP 72357 | 9.55 |
| 2026-07-31 00:00 | 14:47:41.51 | -26:13:29.2 | HIP 72357 | 8.27 |
| 2026-07-31 12:00 | 14:47:56.44 | -26:13:05.0 | HIP 72357 | 8.26 |
| 2026-08-01 00:00 | 14:48:11.58 | -26:12:42.1 | HIP 72357 | 9.58 |
| 2026-08-01 12:00 | 14:48:26.93 | -26:12:20.2 | HIP 72357 | 11.82 |
| 2026-08-02 00:00 | 14:48:42.51 | -26:11:59.5 | HIP 72509 | 12.45 |
| 2026-08-02 12:00 | 14:48:58.29 | -26:11:39.9 | HIP 72509 | 9.19 |
| 2026-08-03 00:00 | 14:49:14.30 | -26:11:21.4 | HIP 72509 | 6.24 |
| 2026-08-03 12:00 | 14:49:30.51 | -26:11:04.0 | HIP 72509 | 4.42 |
| 2026-08-04 00:00 | 14:49:46.93 | -26:10:47.7 | HIP 72509 | 5.22 |
| 2026-08-04 12:00 | 14:50:03.57 | -26:10:32.6 | HIP 72511 | 7.94 |
| 2026-08-05 00:00 | 14:50:20.41 | -26:10:18.5 | HIP 72511 | 11.24 |
| 2026-08-05 12:00 | 14:50:37.46 | -26:10:05.5 | HIP 72511 | 14.83 |
| 2026-08-06 00:00 | 14:50:54.71 | -26:09:53.5 | HIP 72511 | 18.56 |
| 2026-08-06 12:00 | 14:51:12.17 | -26:09:42.7 | HIP 72511 | 22.40 |
| 2026-08-07 00:00 | 14:51:29.84 | -26:09:32.9 | HIP 72511 | 26.30 |
| 2026-08-07 12:00 | 14:51:47.71 | -26:09:24.2 | HIP 72733 | 28.55 |
| 2026-08-08 00:00 | 14:52:05.78 | -26:09:16.5 | HIP 72733 | 28.15 |
| 2026-08-08 12:00 | 14:52:24.05 | -26:09:09.9 | HIP 72733 | 28.31 |
| 2026-08-09 00:00 | 14:52:42.52 | -26:09:04.3 | HIP 72733 | 29.04 |
| 2026-08-09 12:00 | 14:53:01.19 | -26:08:59.8 | HIP 72733 | 30.32 |
| 2026-08-10 00:00 | 14:53:20.05 | -26:08:56.3 | HIP 72733 | 32.11 |
| 2026-08-10 12:00 | 14:53:39.12 | -26:08:53.8 | HIP 72867 | 32.84 |
| 2026-08-11 00:00 | 14:53:58.37 | -26:08:52.3 | HIP 72867 | 33.12 |
| 2026-08-11 12:00 | 14:54:17.82 | -26:08:51.8 | HIP 72867 | 33.98 |
| 2026-08-12 00:00 | 14:54:37.47 | -26:08:52.4 | HIP 73150 | 32.46 |
| 2026-08-12 12:00 | 14:54:57.30 | -26:08:53.9 | HIP 73150 | 28.17 |
| 2026-08-13 00:00 | 14:55:17.33 | -26:08:56.4 | HIP 73150 | 23.89 |
| 2026-08-13 12:00 | 14:55:37.55 | -26:08:59.9 | HIP 73150 | 19.67 |
| 2026-08-14 00:00 | 14:55:57.95 | -26:09:04.4 | HIP 73150 | 15.58 |
| 2026-08-14 12:00 | 14:56:18.54 | -26:09:09.8 | HIP 73150 | 11.80 |
| 2026-08-15 00:00 | 14:56:39.31 | -26:09:16.2 | HIP 73150 | 8.82 |
| 2026-08-15 12:00 | 14:57:00.27 | -26:09:23.5 | HIP 73150 | 7.73 |
| 2026-08-16 00:00 | 14:57:21.41 | -26:09:31.8 | HIP 73150 | 9.28 |
| 2026-08-16 12:00 | 14:57:42.73 | -26:09:40.9 | HIP 73150 | 12.57 |
| 2026-08-17 00:00 | 14:58:04.23 | -26:09:51.1 | HIP 73339 | 15.56 |
| 2026-08-17 12:00 | 14:58:25.90 | -26:10:02.1 | HIP 73339 | 10.77 |
| 2026-08-18 00:00 | 14:58:47.76 | -26:10:14.0 | HIP 73339 | 6.07 |
| 2026-08-18 12:00 | 14:59:09.79 | -26:10:26.8 | HIP 73339 | 2.45 |
| 2026-08-19 00:00 | 14:59:31.99 | -26:10:40.5 | HIP 73339 | 4.95 |