C/2024 G3 (ATLAS)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2024 G3 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2025-01-13T10:11:01.593600Z |
| Orbit solution date (soln_date, UTC) | 2025-04-11T14:44:56Z |
| Obs used | 299 |
| NEO | - |
| M1 | 7.600 |
| K1 | 12.500 |
| PC | 0.030 |
| Discovery observation (MPC, UTC) | 2024-04-05T06:19:43.334400Z |
| Discovery magnitude (MPC) | 19.21 o |
| Discovery observatory (MPC) | W68 · ATLAS Chile, Rio Hurtado |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2024-06-19.0000000 |
| e | 1.00001229 |
| q (au) | 0.093493 |
| a (au) | -7606.453070 |
| i (deg) | 116.851095 |
| Ω (om, deg) | 220.332091 |
| ω (w, deg) | 108.125373 |
| M (ma, deg) | -0.000310 |
Magnitude
Scatter + Global Linear
$$ M_a = (8.414 + 4.556\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 8.414 |
| n | 4.556 |
| gf | 0.800 |
| gb | -0.506 |
| k | 0.800 |
| 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 |
|---|---|---|---|
| 2024-04-05 | 2025-01-03 | +1.9192 | -0.824 |
| 2025-01-03 | 2025-01-11 | -4.0733 | -3.425 |
| 2025-01-11 | 2025-01-13 | -1.4868 | -1.082 |
| 2025-01-13 | 2025-05-20 | -2.4763 | -2.598 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 23:28:24.49 | -84:43:20.6 | HIP 114668 | 26.11 |
| 2026-09-20 12:00 | 23:25:47.07 | -84:43:01.7 | HIP 114668 | 23.81 |
| 2026-09-21 00:00 | 23:23:10.47 | -84:42:38.4 | HIP 114306 | 21.82 |
| 2026-09-21 12:00 | 23:20:34.79 | -84:42:10.8 | HIP 114306 | 19.03 |
| 2026-09-22 00:00 | 23:18:00.11 | -84:41:39.0 | HIP 114306 | 16.60 |
| 2026-09-22 12:00 | 23:15:26.52 | -84:41:02.9 | HIP 114306 | 14.69 |
| 2026-09-23 00:00 | 23:12:54.11 | -84:40:22.6 | HIP 114306 | 13.52 |
| 2026-09-23 12:00 | 23:10:22.96 | -84:39:38.2 | HIP 114306 | 13.29 |
| 2026-09-24 00:00 | 23:07:53.15 | -84:38:49.6 | HIP 114306 | 14.04 |
| 2026-09-24 12:00 | 23:05:24.75 | -84:37:57.1 | HIP 114306 | 15.62 |
| 2026-09-25 00:00 | 23:02:57.83 | -84:37:00.6 | HIP 114306 | 17.80 |
| 2026-09-25 12:00 | 23:00:32.47 | -84:36:00.1 | HIP 114306 | 20.40 |
| 2026-09-26 00:00 | 22:58:08.73 | -84:34:55.9 | HIP 112859 | 21.54 |
| 2026-09-26 12:00 | 22:55:46.67 | -84:33:47.8 | HIP 112859 | 19.11 |
| 2026-09-27 00:00 | 22:53:26.34 | -84:32:35.9 | HIP 112859 | 17.06 |
| 2026-09-27 12:00 | 22:51:07.80 | -84:31:20.4 | HIP 112859 | 15.52 |
| 2026-09-28 00:00 | 22:48:51.10 | -84:30:01.3 | HIP 112859 | 14.66 |
| 2026-09-28 12:00 | 22:46:36.28 | -84:28:38.7 | HIP 112859 | 14.58 |
| 2026-09-29 00:00 | 22:44:23.39 | -84:27:12.6 | HIP 112859 | 15.30 |
| 2026-09-29 12:00 | 22:42:12.46 | -84:25:43.0 | HIP 112859 | 16.72 |
| 2026-09-30 00:00 | 22:40:03.53 | -84:24:10.2 | HIP 111982 | 16.03 |
| 2026-09-30 12:00 | 22:37:56.63 | -84:22:34.0 | HIP 111982 | 15.07 |
| 2026-10-01 00:00 | 22:35:51.79 | -84:20:54.7 | HIP 111982 | 14.86 |
| 2026-10-01 12:00 | 22:33:49.03 | -84:19:12.2 | HIP 111982 | 15.42 |
| 2026-10-02 00:00 | 22:31:48.37 | -84:17:26.6 | HIP 111982 | 16.67 |
| 2026-10-02 12:00 | 22:29:49.84 | -84:15:38.1 | HIP 111982 | 18.47 |
| 2026-10-03 00:00 | 22:27:53.44 | -84:13:46.6 | HIP 111982 | 20.67 |
| 2026-10-03 12:00 | 22:25:59.19 | -84:11:52.2 | HIP 111982 | 23.15 |
| 2026-10-04 00:00 | 22:24:07.11 | -84:09:55.1 | HIP 111982 | 25.83 |
| 2026-10-04 12:00 | 22:22:17.19 | -84:07:55.2 | HIP 111982 | 28.65 |
| 2026-10-05 00:00 | 22:20:29.44 | -84:05:52.7 | HIP 108744 | 30.55 |
| 2026-10-05 12:00 | 22:18:43.86 | -84:03:47.6 | HIP 108744 | 27.43 |
| 2026-10-06 00:00 | 22:17:00.46 | -84:01:39.9 | HIP 108744 | 24.41 |
| 2026-10-06 12:00 | 22:15:19.22 | -83:59:29.8 | HIP 108744 | 21.54 |
| 2026-10-07 00:00 | 22:13:40.16 | -83:57:17.3 | HIP 108744 | 18.87 |
| 2026-10-07 12:00 | 22:12:03.24 | -83:55:02.4 | HIP 108744 | 16.51 |
| 2026-10-08 00:00 | 22:10:28.48 | -83:52:45.3 | HIP 108744 | 14.60 |
| 2026-10-08 12:00 | 22:08:55.86 | -83:50:26.0 | HIP 108744 | 13.33 |
| 2026-10-09 00:00 | 22:07:25.36 | -83:48:04.6 | HIP 108744 | 12.89 |
| 2026-10-09 12:00 | 22:05:56.98 | -83:45:41.0 | HIP 108744 | 13.35 |
| 2026-10-10 00:00 | 22:04:30.69 | -83:43:15.5 | HIP 108322 | 12.80 |
| 2026-10-10 12:00 | 22:03:06.49 | -83:40:48.0 | HIP 108322 | 10.89 |
| 2026-10-11 00:00 | 22:01:44.34 | -83:38:18.7 | HIP 108322 | 9.84 |