C/2025 N2 (ATLAS)
| Parameter |
Value |
| Designation |
C/2025 N2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2024-12-11T00:44:51.385920Z |
| Orbit solution date (soln_date, UTC) |
2025-12-18T15:12:23Z |
| Obs used |
47 |
| NEO |
- |
| M1 |
4.900 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-07-02T01:33:05.932800Z |
| Discovery magnitude (MPC) |
19.61 c |
| Discovery observatory (MPC) |
M22 · ATLAS South Africa, Sutherland |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2025-08-26.0000000 |
| e |
1.00252212 |
| q (au) |
8.983070 |
| a (au) |
-3561.711006 |
| i (deg) |
81.665566 |
| Ω (om, deg) |
94.465158 |
| ω (w, deg) |
230.022476 |
| M (ma, deg) |
0.001196 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.205 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.205 |
| n |
2.000 |
| gf |
0.811 |
| gb |
-0.569 |
| k |
0.892 |
| δ90 |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
00:17:21.95 |
-76:53:39.2 |
HIP 1623 |
22.01 |
| 2026-02-03 12:00 |
00:18:18.06 |
-76:51:03.1 |
HIP 1838 |
18.65 |
| 2026-02-04 00:00 |
00:19:14.15 |
-76:48:27.1 |
HIP 1838 |
14.72 |
| 2026-02-04 12:00 |
00:20:10.21 |
-76:45:51.3 |
HIP 1838 |
10.92 |
| 2026-02-05 00:00 |
00:21:06.25 |
-76:43:15.6 |
HIP 1838 |
7.46 |
| 2026-02-05 12:00 |
00:22:02.26 |
-76:40:40.0 |
HIP 1838 |
5.08 |
| 2026-02-06 00:00 |
00:22:58.26 |
-76:38:04.6 |
HIP 1838 |
5.48 |
| 2026-02-06 12:00 |
00:23:54.23 |
-76:35:29.4 |
HIP 1838 |
8.27 |
| 2026-02-07 00:00 |
00:24:50.17 |
-76:32:54.3 |
HIP 1838 |
11.87 |
| 2026-02-07 12:00 |
00:25:46.09 |
-76:30:19.3 |
HIP 2126 |
12.16 |
| 2026-02-08 00:00 |
00:26:41.99 |
-76:27:44.5 |
HIP 2126 |
8.88 |
| 2026-02-08 12:00 |
00:27:37.86 |
-76:25:09.9 |
HIP 2126 |
6.69 |
| 2026-02-09 00:00 |
00:28:33.71 |
-76:22:35.5 |
HIP 2126 |
6.76 |
| 2026-02-09 12:00 |
00:29:29.54 |
-76:20:01.2 |
HIP 2126 |
9.05 |
| 2026-02-10 00:00 |
00:30:25.34 |
-76:17:27.2 |
HIP 2126 |
12.39 |
| 2026-02-10 12:00 |
00:31:21.11 |
-76:14:53.3 |
HIP 2126 |
16.14 |
| 2026-02-11 00:00 |
00:32:16.86 |
-76:12:19.6 |
HIP 2907 |
17.36 |
| 2026-02-11 12:00 |
00:33:12.58 |
-76:09:46.1 |
HIP 2907 |
15.63 |
| 2026-02-12 00:00 |
00:34:08.28 |
-76:07:12.8 |
HIP 2907 |
14.88 |
| 2026-02-12 12:00 |
00:35:03.95 |
-76:04:39.7 |
HIP 2907 |
15.27 |
| 2026-02-13 00:00 |
00:35:59.60 |
-76:02:06.8 |
HIP 2907 |
16.73 |
| 2026-02-13 12:00 |
00:36:55.22 |
-75:59:34.1 |
HIP 2907 |
19.01 |
| 2026-02-14 00:00 |
00:37:50.81 |
-75:57:01.7 |
HIP 3247 |
15.28 |
| 2026-02-14 12:00 |
00:38:46.38 |
-75:54:29.4 |
HIP 3247 |
11.07 |
| 2026-02-15 00:00 |
00:39:41.91 |
-75:51:57.4 |
HIP 3247 |
6.88 |
| 2026-02-15 12:00 |
00:40:37.42 |
-75:49:25.7 |
HIP 3247 |
2.78 |
| 2026-02-16 00:00 |
00:41:32.91 |
-75:46:54.2 |
HIP 3247 |
1.99 |
| 2026-02-16 12:00 |
00:42:28.36 |
-75:44:22.9 |
HIP 3247 |
6.01 |
| 2026-02-17 00:00 |
00:43:23.79 |
-75:41:51.8 |
HIP 3247 |
10.21 |
| 2026-02-17 12:00 |
00:44:19.19 |
-75:39:21.1 |
HIP 3247 |
14.44 |
| 2026-02-18 00:00 |
00:45:14.56 |
-75:36:50.5 |
HIP 3561 |
18.30 |
| 2026-02-18 12:00 |
00:46:09.90 |
-75:34:20.3 |
HIP 3561 |
20.90 |
| 2026-02-19 00:00 |
00:47:05.20 |
-75:31:50.3 |
HIP 3561 |
23.97 |
| 2026-02-19 12:00 |
00:48:00.48 |
-75:29:20.6 |
HIP 3561 |
27.34 |
| 2026-02-20 00:00 |
00:48:55.73 |
-75:26:51.1 |
HIP 4415 |
28.89 |
| 2026-02-20 12:00 |
00:49:50.95 |
-75:24:22.0 |
HIP 4415 |
25.35 |
| 2026-02-21 00:00 |
00:50:46.13 |
-75:21:53.1 |
HIP 4415 |
22.05 |
| 2026-02-21 12:00 |
00:51:41.29 |
-75:19:24.5 |
HIP 4415 |
19.11 |
| 2026-02-22 00:00 |
00:52:36.41 |
-75:16:56.2 |
HIP 4415 |
16.74 |
| 2026-02-22 12:00 |
00:53:31.49 |
-75:14:28.3 |
HIP 4415 |
15.20 |
| 2026-02-23 00:00 |
00:54:26.55 |
-75:12:00.6 |
HIP 4415 |
14.77 |
| 2026-02-23 12:00 |
00:55:21.57 |
-75:09:33.2 |
HIP 4415 |
15.53 |
| 2026-02-24 00:00 |
00:56:16.55 |
-75:07:06.1 |
HIP 4415 |
17.33 |