C/2024 S1 (ATLAS)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2024 S1 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2024-10-28T11:39:10.923840Z |
| Orbit solution date (soln_date, UTC) | 2025-09-09T12:42:42Z |
| Obs used | 289 |
| 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 | 0.99991737 |
| q (au) | 0.007954 |
| a (au) | 96.258164 |
| i (deg) | 141.901469 |
| Ω (om, deg) | 347.150011 |
| ω (w, deg) | 69.163122 |
| M (ma, deg) | 359.975490 |
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) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 07:07:21.14 | -08:21:55.9 | HIP 34486 | 28.63 |
| 2026-07-29 12:00 | 07:07:32.95 | -08:22:55.6 | HIP 34486 | 25.80 |
| 2026-07-30 00:00 | 07:07:44.72 | -08:23:56.0 | HIP 34491 | 23.02 |
| 2026-07-30 12:00 | 07:07:56.44 | -08:24:57.0 | HIP 34491 | 20.31 |
| 2026-07-31 00:00 | 07:08:08.11 | -08:25:58.8 | HIP 34491 | 17.72 |
| 2026-07-31 12:00 | 07:08:19.75 | -08:27:01.2 | HIP 34491 | 15.31 |
| 2026-08-01 00:00 | 07:08:31.33 | -08:28:04.4 | HIP 34491 | 13.16 |
| 2026-08-01 12:00 | 07:08:42.87 | -08:29:08.2 | HIP 34491 | 11.41 |
| 2026-08-02 00:00 | 07:08:54.37 | -08:30:12.6 | HIP 34491 | 10.28 |
| 2026-08-02 12:00 | 07:09:05.82 | -08:31:17.8 | HIP 34491 | 9.96 |
| 2026-08-03 00:00 | 07:09:17.22 | -08:32:23.6 | HIP 34491 | 10.53 |
| 2026-08-03 12:00 | 07:09:28.57 | -08:33:30.0 | HIP 34491 | 11.85 |
| 2026-08-04 00:00 | 07:09:39.87 | -08:34:37.2 | HIP 34491 | 13.70 |
| 2026-08-04 12:00 | 07:09:51.12 | -08:35:45.0 | HIP 34491 | 15.89 |
| 2026-08-05 00:00 | 07:10:02.33 | -08:36:53.4 | HIP 34491 | 18.30 |
| 2026-08-05 12:00 | 07:10:13.48 | -08:38:02.5 | HIP 34491 | 20.85 |
| 2026-08-06 00:00 | 07:10:24.58 | -08:39:12.3 | HIP 34491 | 23.49 |
| 2026-08-06 12:00 | 07:10:35.63 | -08:40:22.7 | HIP 34491 | 26.19 |
| 2026-08-07 00:00 | 07:10:46.63 | -08:41:33.7 | HIP 34491 | 28.93 |
| 2026-08-07 12:00 | 07:10:57.58 | -08:42:45.4 | HIP 34491 | 31.69 |
| 2026-08-08 00:00 | 07:11:08.47 | -08:43:57.8 | HIP 34720 | 33.15 |
| 2026-08-08 12:00 | 07:11:19.31 | -08:45:10.8 | HIP 34906 | 30.72 |
| 2026-08-09 00:00 | 07:11:30.09 | -08:46:24.4 | HIP 34906 | 27.86 |
| 2026-08-09 12:00 | 07:11:40.81 | -08:47:38.6 | HIP 34906 | 25.03 |
| 2026-08-10 00:00 | 07:11:51.48 | -08:48:53.5 | HIP 34906 | 22.24 |
| 2026-08-10 12:00 | 07:12:02.10 | -08:50:09.0 | HIP 34906 | 19.50 |
| 2026-08-11 00:00 | 07:12:12.65 | -08:51:25.1 | HIP 34906 | 16.83 |
| 2026-08-11 12:00 | 07:12:23.15 | -08:52:41.9 | HIP 34906 | 14.26 |
| 2026-08-12 00:00 | 07:12:33.59 | -08:53:59.3 | HIP 34906 | 11.86 |
| 2026-08-12 12:00 | 07:12:43.96 | -08:55:17.2 | HIP 34906 | 9.75 |
| 2026-08-13 00:00 | 07:12:54.28 | -08:56:35.8 | HIP 34906 | 8.14 |
| 2026-08-13 12:00 | 07:13:04.54 | -08:57:55.0 | HIP 34906 | 7.35 |
| 2026-08-14 00:00 | 07:13:14.73 | -08:59:14.8 | HIP 34906 | 7.64 |
| 2026-08-14 12:00 | 07:13:24.86 | -09:00:35.2 | HIP 34933 | 6.66 |
| 2026-08-15 00:00 | 07:13:34.93 | -09:01:56.1 | HIP 34933 | 6.67 |
| 2026-08-15 12:00 | 07:13:44.94 | -09:03:17.7 | HIP 34933 | 7.80 |
| 2026-08-16 00:00 | 07:13:54.88 | -09:04:39.8 | HIP 34933 | 9.66 |
| 2026-08-16 12:00 | 07:14:04.75 | -09:06:02.5 | HIP 34970 | 9.45 |
| 2026-08-17 00:00 | 07:14:14.56 | -09:07:25.8 | HIP 34970 | 8.07 |
| 2026-08-17 12:00 | 07:14:24.30 | -09:08:49.6 | HIP 34970 | 7.50 |
| 2026-08-18 00:00 | 07:14:33.98 | -09:10:14.0 | HIP 34970 | 7.91 |
| 2026-08-18 12:00 | 07:14:43.59 | -09:11:39.0 | HIP 35050 | 8.19 |
| 2026-08-19 00:00 | 07:14:53.13 | -09:13:04.5 | HIP 35050 | 9.16 |