C/2024 A1 (ATLAS)
| Parameter |
Value |
| Designation |
C/2024 A1 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-06-13T17:27:07.937280Z |
| Orbit solution date (soln_date, UTC) |
2026-01-13T08:12:19Z |
| Obs used |
1566 |
| NEO |
- |
| M1 |
11.400 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2024-01-03T04:58:49.900800Z |
| Discovery magnitude (MPC) |
18.80 o |
| Discovery observatory (MPC) |
W68 · ATLAS Chile, Rio Hurtado |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2025-02-15.0000000 |
| e |
1.00172507 |
| q (au) |
3.875307 |
| a (au) |
-2246.468048 |
| i (deg) |
94.448750 |
| Ω (om, deg) |
112.139764 |
| ω (w, deg) |
353.313303 |
| M (ma, deg) |
-0.001099 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.334 + 2.719\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.334 |
| n |
2.719 |
| gf |
0.817 |
| gb |
-0.718 |
| k |
0.998 |
| δ90 |
1.001 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
07:13:37.27 |
+62:39:58.8 |
HIP 34825 |
25.52 |
| 2026-02-03 12:00 |
07:12:35.44 |
+62:43:06.6 |
HIP 34825 |
27.37 |
| 2026-02-04 00:00 |
07:11:33.89 |
+62:46:09.4 |
HIP 34825 |
31.04 |
| 2026-02-04 12:00 |
07:10:32.63 |
+62:49:07.4 |
HIP 34274 |
28.84 |
| 2026-02-05 00:00 |
07:09:31.68 |
+62:52:00.5 |
HIP 34274 |
21.86 |
| 2026-02-05 12:00 |
07:08:31.04 |
+62:54:48.9 |
HIP 34274 |
15.46 |
| 2026-02-06 00:00 |
07:07:30.74 |
+62:57:32.5 |
HIP 34274 |
10.57 |
| 2026-02-06 12:00 |
07:06:30.78 |
+63:00:11.4 |
HIP 34274 |
9.61 |
| 2026-02-07 00:00 |
07:05:31.17 |
+63:02:45.7 |
HIP 34274 |
13.34 |
| 2026-02-07 12:00 |
07:04:31.94 |
+63:05:15.5 |
HIP 34274 |
19.11 |
| 2026-02-08 00:00 |
07:03:33.09 |
+63:07:40.7 |
HIP 34274 |
25.51 |
| 2026-02-08 12:00 |
07:02:34.64 |
+63:10:01.5 |
HIP 33986 |
29.83 |
| 2026-02-09 00:00 |
07:01:36.59 |
+63:12:17.8 |
HIP 33518 |
26.32 |
| 2026-02-09 12:00 |
07:00:38.96 |
+63:14:29.8 |
HIP 33518 |
21.56 |
| 2026-02-10 00:00 |
06:59:41.76 |
+63:16:37.6 |
HIP 33518 |
18.21 |
| 2026-02-10 12:00 |
06:58:45.00 |
+63:18:41.1 |
HIP 33518 |
17.00 |
| 2026-02-11 00:00 |
06:57:48.69 |
+63:20:40.4 |
HIP 33518 |
18.29 |
| 2026-02-11 12:00 |
06:56:52.85 |
+63:22:35.6 |
HIP 33518 |
21.56 |
| 2026-02-12 00:00 |
06:55:57.48 |
+63:24:26.8 |
HIP 33518 |
26.02 |
| 2026-02-12 12:00 |
06:55:02.59 |
+63:26:14.0 |
HIP 33518 |
31.12 |
| 2026-02-13 00:00 |
06:54:08.20 |
+63:27:57.3 |
HIP 33151 |
30.94 |
| 2026-02-13 12:00 |
06:53:14.31 |
+63:29:36.7 |
HIP 32888 |
29.48 |
| 2026-02-14 00:00 |
06:52:20.94 |
+63:31:12.3 |
HIP 32888 |
28.69 |
| 2026-02-14 12:00 |
06:51:28.08 |
+63:32:44.2 |
HIP 32888 |
29.17 |
| 2026-02-15 00:00 |
06:50:35.76 |
+63:34:12.5 |
HIP 32888 |
30.82 |
| 2026-02-15 12:00 |
06:49:43.98 |
+63:35:37.1 |
HIP 32888 |
33.42 |
| 2026-02-16 00:00 |
06:48:52.74 |
+63:36:58.2 |
HIP 32545 |
34.97 |
| 2026-02-16 12:00 |
06:48:02.06 |
+63:38:15.9 |
HIP 32545 |
35.16 |
| 2026-02-17 00:00 |
06:47:11.94 |
+63:39:30.1 |
HIP 32105 |
33.80 |
| 2026-02-17 12:00 |
06:46:22.39 |
+63:40:41.1 |
HIP 32105 |
29.10 |
| 2026-02-18 00:00 |
06:45:33.42 |
+63:41:48.7 |
HIP 32105 |
24.83 |
| 2026-02-18 12:00 |
06:44:45.03 |
+63:42:53.2 |
HIP 32105 |
21.18 |
| 2026-02-19 00:00 |
06:43:57.23 |
+63:43:54.5 |
HIP 32105 |
18.46 |
| 2026-02-19 12:00 |
06:43:10.03 |
+63:44:52.8 |
HIP 32105 |
17.05 |
| 2026-02-20 00:00 |
06:42:23.43 |
+63:45:48.0 |
HIP 32105 |
17.20 |
| 2026-02-20 12:00 |
06:41:37.43 |
+63:46:40.4 |
HIP 32105 |
18.81 |
| 2026-02-21 00:00 |
06:40:52.05 |
+63:47:29.9 |
HIP 32105 |
21.50 |
| 2026-02-21 12:00 |
06:40:07.28 |
+63:48:16.5 |
HIP 32105 |
24.88 |
| 2026-02-22 00:00 |
06:39:23.13 |
+63:49:00.5 |
HIP 32105 |
28.66 |
| 2026-02-22 12:00 |
06:38:39.60 |
+63:49:41.8 |
HIP 31422 |
29.40 |
| 2026-02-23 00:00 |
06:37:56.70 |
+63:50:20.5 |
HIP 31422 |
26.13 |
| 2026-02-23 12:00 |
06:37:14.44 |
+63:50:56.6 |
HIP 31422 |
23.40 |
| 2026-02-24 00:00 |
06:36:32.80 |
+63:51:30.3 |
HIP 31422 |
21.37 |