| Parameter |
Value |
| Designation |
C/2024 A2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2024-04-28T21:48:07.764480Z |
| Orbit solution date (soln_date, UTC) |
2025-02-13T09:12:46Z |
| Obs used |
497 |
| NEO |
- |
| M1 |
14.600 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2024-01-15T08:03:10.915200Z |
| Discovery magnitude (MPC) |
18.04 o |
| Discovery observatory (MPC) |
W68 · ATLAS Chile, Rio Hurtado |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2024-07-05.0000000 |
| e |
0.94184736 |
| q (au) |
1.881640 |
| a (au) |
32.356907 |
| i (deg) |
119.111392 |
| Ω (om, deg) |
78.167124 |
| ω (w, deg) |
295.581197 |
| M (ma, deg) |
0.359271 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.792 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.792 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.726 |
| k |
0.995 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
00:26:29.72 |
+65:09:48.7 |
HIP 2037 |
13.77 |
| 2026-09-20 12:00 |
00:25:48.34 |
+65:09:33.6 |
HIP 2037 |
13.46 |
| 2026-09-21 00:00 |
00:25:06.92 |
+65:09:16.0 |
HIP 2037 |
14.54 |
| 2026-09-21 12:00 |
00:24:25.48 |
+65:08:55.9 |
HIP 2037 |
16.75 |
| 2026-09-22 00:00 |
00:23:44.01 |
+65:08:33.4 |
HIP 2037 |
19.72 |
| 2026-09-22 12:00 |
00:23:02.52 |
+65:08:08.4 |
HIP 2037 |
23.17 |
| 2026-09-23 00:00 |
00:22:21.02 |
+65:07:40.9 |
HIP 2037 |
26.90 |
| 2026-09-23 12:00 |
00:21:39.51 |
+65:07:10.9 |
HIP 1405 |
27.17 |
| 2026-09-24 00:00 |
00:20:58.01 |
+65:06:38.5 |
HIP 1405 |
23.32 |
| 2026-09-24 12:00 |
00:20:16.51 |
+65:06:03.6 |
HIP 1405 |
19.72 |
| 2026-09-25 00:00 |
00:19:35.02 |
+65:05:26.3 |
HIP 1405 |
16.53 |
| 2026-09-25 12:00 |
00:18:53.55 |
+65:04:46.5 |
HIP 1405 |
14.04 |
| 2026-09-26 00:00 |
00:18:12.11 |
+65:04:04.2 |
HIP 1405 |
12.68 |
| 2026-09-26 12:00 |
00:17:30.69 |
+65:03:19.5 |
HIP 1405 |
12.81 |
| 2026-09-27 00:00 |
00:16:49.31 |
+65:02:32.3 |
HIP 1405 |
14.41 |
| 2026-09-27 12:00 |
00:16:07.96 |
+65:01:42.7 |
HIP 1405 |
17.07 |
| 2026-09-28 00:00 |
00:15:26.67 |
+65:00:50.6 |
HIP 1105 |
13.89 |
| 2026-09-28 12:00 |
00:14:45.42 |
+64:59:56.2 |
HIP 1105 |
10.19 |
| 2026-09-29 00:00 |
00:14:04.23 |
+64:58:59.2 |
HIP 1105 |
7.34 |
| 2026-09-29 12:00 |
00:13:23.11 |
+64:57:59.9 |
HIP 1105 |
6.59 |
| 2026-09-30 00:00 |
00:12:42.05 |
+64:56:58.1 |
HIP 1105 |
8.51 |
| 2026-09-30 12:00 |
00:12:01.07 |
+64:55:53.9 |
HIP 890 |
7.14 |
| 2026-10-01 00:00 |
00:11:20.16 |
+64:54:47.3 |
HIP 890 |
3.94 |
| 2026-10-01 12:00 |
00:10:39.34 |
+64:53:38.3 |
HIP 890 |
4.51 |
| 2026-10-02 00:00 |
00:09:58.62 |
+64:52:26.9 |
HIP 890 |
8.10 |
| 2026-10-02 12:00 |
00:09:17.98 |
+64:51:13.1 |
HIP 890 |
12.30 |
| 2026-10-03 00:00 |
00:08:37.45 |
+64:49:56.9 |
HIP 755 |
14.89 |
| 2026-10-03 12:00 |
00:07:57.03 |
+64:48:38.4 |
HIP 834 |
17.31 |
| 2026-10-04 00:00 |
00:07:16.72 |
+64:47:17.5 |
HIP 402 |
14.95 |
| 2026-10-04 12:00 |
00:06:36.53 |
+64:45:54.2 |
HIP 402 |
10.71 |
| 2026-10-05 00:00 |
00:05:56.46 |
+64:44:28.6 |
HIP 402 |
6.84 |
| 2026-10-05 12:00 |
00:05:16.52 |
+64:43:00.7 |
HIP 402 |
4.43 |
| 2026-10-06 00:00 |
00:04:36.71 |
+64:41:30.4 |
HIP 402 |
5.77 |
| 2026-10-06 12:00 |
00:03:57.04 |
+64:39:57.8 |
HIP 402 |
9.38 |
| 2026-10-07 00:00 |
00:03:17.52 |
+64:38:23.0 |
HIP 402 |
13.56 |
| 2026-10-07 12:00 |
00:02:38.15 |
+64:36:45.8 |
HIP 402 |
17.91 |
| 2026-10-08 00:00 |
00:01:58.93 |
+64:35:06.4 |
HIP 402 |
22.33 |
| 2026-10-08 12:00 |
00:01:19.87 |
+64:33:24.7 |
HIP 118240 |
24.97 |
| 2026-10-09 00:00 |
00:00:40.98 |
+64:31:40.8 |
HIP 118168 |
24.16 |
| 2026-10-09 12:00 |
00:00:02.26 |
+64:29:54.7 |
HIP 118168 |
20.15 |
| 2026-10-10 00:00 |
23:59:23.72 |
+64:28:06.3 |
HIP 118168 |
16.39 |
| 2026-10-10 12:00 |
23:58:45.35 |
+64:26:15.8 |
HIP 118168 |
13.10 |
| 2026-10-11 00:00 |
23:58:07.17 |
+64:24:23.1 |
HIP 118168 |
10.73 |