C/2024 R4 (PANSTARRS)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2024 R4 (PANSTARRS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2027-10-26T16:28:53.532480Z |
| Orbit solution date (soln_date, UTC) | 2026-07-28T14:12:17Z |
| Obs used | 1460 |
| NEO | - |
| M1 | 5.900 |
| K1 | 8.000 |
| PC | 0.030 |
| Discovery observation (MPC, UTC) | 2024-09-11T08:54:09.475200Z |
| Discovery magnitude (MPC) | 21.20 w |
| Discovery observatory (MPC) | F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2025-12-01.0000000 |
| e | 1.00254196 |
| q (au) | 4.408725 |
| a (au) | -1734.383382 |
| i (deg) | 95.371876 |
| Ω (om, deg) | 345.940326 |
| ω (w, deg) | 109.001198 |
| M (ma, deg) | -0.009479 |
Magnitude
Scatter + Global Linear
$$ M_a = (2.888 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 2.888 |
| n | 6.000 |
| gf | 1.000 |
| gb | -0.726 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) | End (UTC) | a | b |
|---|---|---|---|
| 2024-07-03 | 2025-04-28 | +25.4016 | -23.108 |
| 2025-04-28 | 2025-12-26 | +4.2957 | -3.775 |
| 2025-12-26 | 2026-08-04 | -3.9564 | +3.249 |
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 | 21:25:15.79 | +48:22:53.7 | HIP 105659 | 15.64 |
| 2026-07-29 12:00 | 21:24:35.00 | +48:25:50.9 | HIP 105659 | 8.97 |
| 2026-07-30 00:00 | 21:23:53.99 | +48:28:45.0 | HIP 105659 | 5.07 |
| 2026-07-30 12:00 | 21:23:12.77 | +48:31:35.9 | HIP 105584 | 0.88 |
| 2026-07-31 00:00 | 21:22:31.34 | +48:34:23.8 | HIP 105584 | 6.92 |
| 2026-07-31 12:00 | 21:21:49.70 | +48:37:08.4 | HIP 105584 | 14.31 |
| 2026-08-01 00:00 | 21:21:07.87 | +48:39:49.9 | HIP 105321 | 11.67 |
| 2026-08-01 12:00 | 21:20:25.85 | +48:42:28.2 | HIP 105321 | 6.36 |
| 2026-08-02 00:00 | 21:19:43.63 | +48:45:03.2 | HIP 105321 | 7.36 |
| 2026-08-02 12:00 | 21:19:01.23 | +48:47:35.0 | HIP 105321 | 13.34 |
| 2026-08-03 00:00 | 21:18:18.64 | +48:50:03.6 | HIP 105030 | 18.58 |
| 2026-08-03 12:00 | 21:17:35.88 | +48:52:28.8 | HIP 105030 | 12.39 |
| 2026-08-04 00:00 | 21:16:52.94 | +48:54:50.7 | HIP 105030 | 8.47 |
| 2026-08-04 12:00 | 21:16:09.84 | +48:57:09.3 | HIP 105030 | 10.00 |
| 2026-08-05 00:00 | 21:15:26.57 | +48:59:24.5 | HIP 105030 | 15.45 |
| 2026-08-05 12:00 | 21:14:43.14 | +49:01:36.3 | HIP 105030 | 22.08 |
| 2026-08-06 00:00 | 21:13:59.56 | +49:03:44.8 | HIP 104715 | 20.20 |
| 2026-08-06 12:00 | 21:13:15.84 | +49:05:49.8 | HIP 104715 | 14.87 |
| 2026-08-07 00:00 | 21:12:31.96 | +49:07:51.4 | HIP 104715 | 12.09 |
| 2026-08-07 12:00 | 21:11:47.95 | +49:09:49.5 | HIP 104564 | 8.86 |
| 2026-08-08 00:00 | 21:11:03.81 | +49:11:44.2 | HIP 104564 | 3.56 |
| 2026-08-08 12:00 | 21:10:19.53 | +49:13:35.4 | HIP 104564 | 7.62 |
| 2026-08-09 00:00 | 21:09:35.14 | +49:15:23.1 | HIP 104564 | 14.65 |
| 2026-08-09 12:00 | 21:08:50.63 | +49:17:07.3 | HIP 104484 | 19.51 |
| 2026-08-10 00:00 | 21:08:06.01 | +49:18:47.9 | HIP 104484 | 25.57 |
| 2026-08-10 12:00 | 21:07:21.28 | +49:20:25.0 | HIP 104258 | 27.01 |
| 2026-08-11 00:00 | 21:06:36.45 | +49:21:58.6 | HIP 104258 | 26.34 |
| 2026-08-11 12:00 | 21:05:51.53 | +49:23:28.6 | HIP 103971 | 20.83 |
| 2026-08-12 00:00 | 21:05:06.52 | +49:24:55.0 | HIP 103971 | 15.53 |
| 2026-08-12 12:00 | 21:04:21.43 | +49:26:17.9 | HIP 103971 | 12.60 |
| 2026-08-13 00:00 | 21:03:36.27 | +49:27:37.1 | HIP 103971 | 13.66 |
| 2026-08-13 12:00 | 21:02:51.03 | +49:28:52.8 | HIP 103829 | 10.07 |
| 2026-08-14 00:00 | 21:02:05.73 | +49:30:04.9 | HIP 103829 | 8.45 |
| 2026-08-14 12:00 | 21:01:20.38 | +49:31:13.4 | HIP 103788 | 9.13 |
| 2026-08-15 00:00 | 21:00:34.97 | +49:32:18.3 | HIP 103788 | 14.27 |
| 2026-08-15 12:00 | 20:59:49.52 | +49:33:19.5 | HIP 103788 | 20.86 |
| 2026-08-16 00:00 | 20:59:04.03 | +49:34:17.2 | HIP 103788 | 27.89 |
| 2026-08-16 12:00 | 20:58:18.50 | +49:35:11.3 | HIP 103360 | 29.75 |
| 2026-08-17 00:00 | 20:57:32.95 | +49:36:01.7 | HIP 103296 | 24.59 |
| 2026-08-17 12:00 | 20:56:47.38 | +49:36:48.6 | HIP 103296 | 18.97 |
| 2026-08-18 00:00 | 20:56:01.80 | +49:37:31.8 | HIP 103296 | 15.06 |
| 2026-08-18 12:00 | 20:55:16.20 | +49:38:11.5 | HIP 103296 | 14.32 |
| 2026-08-19 00:00 | 20:54:30.61 | +49:38:47.5 | HIP 103143 | 9.19 |