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) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 06:25:00.07 | -11:25:49.9 | HIP 30457 | 13.56 |
| 2026-03-26 12:00 | 06:25:00.63 | -11:23:24.1 | HIP 30457 | 14.91 |
| 2026-03-27 00:00 | 06:25:01.34 | -11:20:58.8 | HIP 30457 | 16.53 |
| 2026-03-27 12:00 | 06:25:02.20 | -11:18:34.0 | HIP 30457 | 18.34 |
| 2026-03-28 00:00 | 06:25:03.20 | -11:16:09.9 | HIP 30457 | 20.30 |
| 2026-03-28 12:00 | 06:25:04.35 | -11:13:46.4 | HIP 30543 | 18.04 |
| 2026-03-29 00:00 | 06:25:05.64 | -11:11:23.4 | HIP 30543 | 15.64 |
| 2026-03-29 12:00 | 06:25:07.07 | -11:09:01.1 | HIP 30543 | 13.24 |
| 2026-03-30 00:00 | 06:25:08.65 | -11:06:39.3 | HIP 30543 | 10.85 |
| 2026-03-30 12:00 | 06:25:10.37 | -11:04:18.2 | HIP 30543 | 8.46 |
| 2026-03-31 00:00 | 06:25:12.23 | -11:01:57.7 | HIP 30543 | 6.08 |
| 2026-03-31 12:00 | 06:25:14.23 | -10:59:37.9 | HIP 30543 | 3.72 |
| 2026-04-01 00:00 | 06:25:16.36 | -10:57:18.7 | HIP 30543 | 1.45 |
| 2026-04-01 12:00 | 06:25:18.64 | -10:55:00.1 | HIP 30543 | 1.32 |
| 2026-04-02 00:00 | 06:25:21.05 | -10:52:42.2 | HIP 30543 | 3.57 |
| 2026-04-02 12:00 | 06:25:23.60 | -10:50:24.9 | HIP 30543 | 5.91 |
| 2026-04-03 00:00 | 06:25:26.29 | -10:48:08.3 | HIP 30543 | 8.28 |
| 2026-04-03 12:00 | 06:25:29.11 | -10:45:52.4 | HIP 30543 | 10.64 |
| 2026-04-04 00:00 | 06:25:32.06 | -10:43:37.1 | HIP 30543 | 13.01 |
| 2026-04-04 12:00 | 06:25:35.14 | -10:41:22.5 | HIP 30543 | 15.38 |
| 2026-04-05 00:00 | 06:25:38.36 | -10:39:08.6 | HIP 30543 | 17.74 |
| 2026-04-05 12:00 | 06:25:41.71 | -10:36:55.4 | HIP 30543 | 20.11 |
| 2026-04-06 00:00 | 06:25:45.19 | -10:34:42.9 | HIP 30543 | 22.48 |
| 2026-04-06 12:00 | 06:25:48.80 | -10:32:31.1 | HIP 30543 | 24.85 |
| 2026-04-07 00:00 | 06:25:52.53 | -10:30:20.0 | HIP 30543 | 27.21 |
| 2026-04-07 12:00 | 06:25:56.40 | -10:28:09.6 | HIP 30634 | 26.23 |
| 2026-04-08 00:00 | 06:26:00.39 | -10:25:59.9 | HIP 30634 | 23.92 |
| 2026-04-08 12:00 | 06:26:04.50 | -10:23:50.9 | HIP 30634 | 21.63 |
| 2026-04-09 00:00 | 06:26:08.75 | -10:21:42.7 | HIP 30634 | 19.37 |
| 2026-04-09 12:00 | 06:26:13.11 | -10:19:35.2 | HIP 30634 | 17.15 |
| 2026-04-10 00:00 | 06:26:17.60 | -10:17:28.4 | HIP 30634 | 15.00 |
| 2026-04-10 12:00 | 06:26:22.21 | -10:15:22.4 | HIP 30634 | 12.94 |
| 2026-04-11 00:00 | 06:26:26.95 | -10:13:17.1 | HIP 30634 | 11.03 |
| 2026-04-11 12:00 | 06:26:31.80 | -10:11:12.6 | HIP 30634 | 9.37 |
| 2026-04-12 00:00 | 06:26:36.78 | -10:09:08.9 | HIP 30634 | 8.11 |
| 2026-04-12 12:00 | 06:26:41.87 | -10:07:05.9 | HIP 30634 | 7.47 |
| 2026-04-13 00:00 | 06:26:47.08 | -10:05:03.6 | HIP 30634 | 7.60 |
| 2026-04-13 12:00 | 06:26:52.41 | -10:03:02.2 | HIP 30634 | 8.48 |
| 2026-04-14 00:00 | 06:26:57.86 | -10:01:01.5 | HIP 30634 | 9.91 |
| 2026-04-14 12:00 | 06:27:03.42 | -09:59:01.6 | HIP 30634 | 11.70 |
| 2026-04-15 00:00 | 06:27:09.10 | -09:57:02.5 | HIP 30634 | 13.70 |
| 2026-04-15 12:00 | 06:27:14.89 | -09:55:04.2 | HIP 30634 | 15.84 |
| 2026-04-16 00:00 | 06:27:20.79 | -09:53:06.7 | HIP 30805 | 15.11 |