C/2024 S1 (ATLAS)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2024 S1 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2024-10-28T11:39:17.801280Z |
| Orbit solution date (soln_date, UTC) | 2026-09-15T13:42:26Z |
| Obs used | 297 |
| NEO | - |
| M1 | 15.300 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2024-09-27T14:47:46.464000Z |
| Discovery magnitude (MPC) | 15.30 o |
| Discovery observatory (MPC) | T05 · ATLAS-HKO, Haleakala |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2024-10-05.0000000 |
| e | 0.99991619 |
| q (au) | 0.007953 |
| a (au) | 94.894286 |
| i (deg) | 141.902101 |
| Ω (om, deg) | 347.153924 |
| ω (w, deg) | 69.167455 |
| M (ma, deg) | 359.974959 |
Magnitude
Scatter + Global Linear
$$ M_a = (13.136 + 2.570\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 13.136 |
| n | 2.570 |
| gf | 0.800 |
| gb | -0.500 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) | End (UTC) | a | b |
|---|---|---|---|
| 2024-09-27 | 2024-10-10 | -1.0443 | +0.222 |
| 2024-10-10 | 2024-10-17 | +5.6025 | +1.583 |
| 2024-10-17 | 2024-10-20 | +8.6854 | +1.949 |
| 2024-10-20 | 2024-10-26 | -2.1925 | -1.747 |
| 2024-10-26 | 2024-10-27 | +0.2951 | -0.121 |
| 2024-10-27 | 2024-10-28 | -11.5966 | -13.835 |
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) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 07:22:17.50 | -11:00:12.0 | HIP 35570 | 30.10 |
| 2026-09-20 12:00 | 07:22:21.45 | -11:02:03.7 | HIP 35570 | 30.13 |
| 2026-09-21 00:00 | 07:22:25.29 | -11:03:55.6 | HIP 35570 | 30.29 |
| 2026-09-21 12:00 | 07:22:29.02 | -11:05:47.7 | HIP 35570 | 30.56 |
| 2026-09-22 00:00 | 07:22:32.65 | -11:07:40.1 | HIP 35570 | 30.94 |
| 2026-09-22 12:00 | 07:22:36.18 | -11:09:32.6 | HIP 35570 | 31.43 |
| 2026-09-23 00:00 | 07:22:39.60 | -11:11:25.3 | HIP 35570 | 32.01 |
| 2026-09-23 12:00 | 07:22:42.92 | -11:13:18.2 | HIP 35570 | 32.69 |
| 2026-09-24 00:00 | 07:22:46.13 | -11:15:11.3 | HIP 35570 | 33.46 |
| 2026-09-24 12:00 | 07:22:49.23 | -11:17:04.5 | HIP 35570 | 34.31 |
| 2026-09-25 00:00 | 07:22:52.23 | -11:18:57.9 | HIP 35570 | 35.22 |
| 2026-09-25 12:00 | 07:22:55.12 | -11:20:51.5 | HIP 35675 | 34.53 |
| 2026-09-26 00:00 | 07:22:57.90 | -11:22:45.2 | HIP 35675 | 33.33 |
| 2026-09-26 12:00 | 07:23:00.58 | -11:24:39.1 | HIP 35675 | 32.20 |
| 2026-09-27 00:00 | 07:23:03.14 | -11:26:33.1 | HIP 35675 | 31.13 |
| 2026-09-27 12:00 | 07:23:05.60 | -11:28:27.2 | HIP 35675 | 30.14 |
| 2026-09-28 00:00 | 07:23:07.95 | -11:30:21.4 | HIP 35675 | 29.23 |
| 2026-09-28 12:00 | 07:23:10.19 | -11:32:15.8 | HIP 35675 | 28.41 |
| 2026-09-29 00:00 | 07:23:12.32 | -11:34:10.3 | HIP 35675 | 27.68 |
| 2026-09-29 12:00 | 07:23:14.34 | -11:36:04.9 | HIP 35745 | 26.96 |
| 2026-09-30 00:00 | 07:23:16.25 | -11:37:59.6 | HIP 35745 | 25.54 |
| 2026-09-30 12:00 | 07:23:18.04 | -11:39:54.3 | HIP 35745 | 24.17 |
| 2026-10-01 00:00 | 07:23:19.73 | -11:41:49.2 | HIP 35745 | 22.88 |
| 2026-10-01 12:00 | 07:23:21.30 | -11:43:44.1 | HIP 35745 | 21.67 |
| 2026-10-02 00:00 | 07:23:22.76 | -11:45:39.1 | HIP 35745 | 20.55 |
| 2026-10-02 12:00 | 07:23:24.11 | -11:47:34.2 | HIP 35745 | 19.54 |
| 2026-10-03 00:00 | 07:23:25.34 | -11:49:29.3 | HIP 35745 | 18.65 |
| 2026-10-03 12:00 | 07:23:26.46 | -11:51:24.5 | HIP 35745 | 17.91 |
| 2026-10-04 00:00 | 07:23:27.47 | -11:53:19.7 | HIP 35745 | 17.33 |
| 2026-10-04 12:00 | 07:23:28.36 | -11:55:14.9 | HIP 35745 | 16.92 |
| 2026-10-05 00:00 | 07:23:29.14 | -11:57:10.2 | HIP 35745 | 16.70 |
| 2026-10-05 12:00 | 07:23:29.80 | -11:59:05.5 | HIP 35745 | 16.67 |
| 2026-10-06 00:00 | 07:23:30.35 | -12:01:00.8 | HIP 35745 | 16.83 |
| 2026-10-06 12:00 | 07:23:30.78 | -12:02:56.1 | HIP 35936 | 16.90 |
| 2026-10-07 00:00 | 07:23:31.09 | -12:04:51.4 | HIP 35936 | 15.87 |
| 2026-10-07 12:00 | 07:23:31.28 | -12:06:46.6 | HIP 35936 | 15.05 |
| 2026-10-08 00:00 | 07:23:31.36 | -12:08:41.8 | HIP 35936 | 14.46 |
| 2026-10-08 12:00 | 07:23:31.32 | -12:10:37.0 | HIP 35936 | 14.15 |
| 2026-10-09 00:00 | 07:23:31.17 | -12:12:32.2 | HIP 35936 | 14.11 |
| 2026-10-09 12:00 | 07:23:30.89 | -12:14:27.3 | HIP 35936 | 14.37 |
| 2026-10-10 00:00 | 07:23:30.50 | -12:16:22.3 | HIP 35936 | 14.90 |
| 2026-10-10 12:00 | 07:23:29.98 | -12:18:17.3 | HIP 35936 | 15.67 |
| 2026-10-11 00:00 | 07:23:29.35 | -12:20:12.2 | HIP 35936 | 16.66 |