| Parameter |
Value |
| Designation |
C/2025 F1 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-04-20T11:22:51.692160Z |
| Orbit solution date (soln_date, UTC) |
2025-06-30T18:47:30Z |
| Obs used |
69 |
| NEO |
- |
| M1 |
15.800 |
| K1 |
44.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-03-22T00:57:23.299200Z |
| Discovery magnitude (MPC) |
19.16 c |
| Discovery observatory (MPC) |
W68 · ATLAS Chile, Rio Hurtado |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2025-04-03.0000000 |
| e |
0.99629808 |
| q (au) |
1.069969 |
| a (au) |
289.030892 |
| i (deg) |
109.235882 |
| Ω (om, deg) |
122.704828 |
| ω (w, deg) |
334.230510 |
| M (ma, deg) |
359.996495 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.487 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.487 |
| n |
6.000 |
| gf |
0.998 |
| gb |
-1.000 |
| k |
0.800 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
22:13:58.47 |
+55:35:41.2 |
HIP 109701 |
17.95 |
| 2026-03-26 12:00 |
22:14:22.98 |
+55:38:10.3 |
HIP 109894 |
14.39 |
| 2026-03-27 00:00 |
22:14:47.29 |
+55:40:40.9 |
HIP 109894 |
10.31 |
| 2026-03-27 12:00 |
22:15:11.41 |
+55:43:12.9 |
HIP 109894 |
6.42 |
| 2026-03-28 00:00 |
22:15:35.34 |
+55:45:46.2 |
HIP 109894 |
3.45 |
| 2026-03-28 12:00 |
22:15:59.07 |
+55:48:21.0 |
HIP 109894 |
4.24 |
| 2026-03-29 00:00 |
22:16:22.60 |
+55:50:57.2 |
HIP 109894 |
7.69 |
| 2026-03-29 12:00 |
22:16:45.94 |
+55:53:34.7 |
HIP 109894 |
11.63 |
| 2026-03-30 00:00 |
22:17:09.08 |
+55:56:13.6 |
HIP 110021 |
14.42 |
| 2026-03-30 12:00 |
22:17:32.02 |
+55:58:53.9 |
HIP 110021 |
12.48 |
| 2026-03-31 00:00 |
22:17:54.76 |
+56:01:35.5 |
HIP 110154 |
9.27 |
| 2026-03-31 12:00 |
22:18:17.30 |
+56:04:18.4 |
HIP 110154 |
5.12 |
| 2026-04-01 00:00 |
22:18:39.65 |
+56:07:02.6 |
HIP 110154 |
0.98 |
| 2026-04-01 12:00 |
22:19:01.79 |
+56:09:48.1 |
HIP 110154 |
3.17 |
| 2026-04-02 00:00 |
22:19:23.72 |
+56:12:35.0 |
HIP 110154 |
7.30 |
| 2026-04-02 12:00 |
22:19:45.46 |
+56:15:23.1 |
HIP 110275 |
10.52 |
| 2026-04-03 00:00 |
22:20:06.99 |
+56:18:12.5 |
HIP 110275 |
7.05 |
| 2026-04-03 12:00 |
22:20:28.32 |
+56:21:03.1 |
HIP 110275 |
4.70 |
| 2026-04-04 00:00 |
22:20:49.44 |
+56:23:55.0 |
HIP 110275 |
5.27 |
| 2026-04-04 12:00 |
22:21:10.35 |
+56:26:48.2 |
HIP 110275 |
8.15 |
| 2026-04-05 00:00 |
22:21:31.06 |
+56:29:42.5 |
HIP 110275 |
11.74 |
| 2026-04-05 12:00 |
22:21:51.56 |
+56:32:38.1 |
HIP 110275 |
15.56 |
| 2026-04-06 00:00 |
22:22:11.85 |
+56:35:34.9 |
HIP 110275 |
19.46 |
| 2026-04-06 12:00 |
22:22:31.92 |
+56:38:32.9 |
HIP 110648 |
20.08 |
| 2026-04-07 00:00 |
22:22:51.79 |
+56:41:32.1 |
HIP 110648 |
16.96 |
| 2026-04-07 12:00 |
22:23:11.44 |
+56:44:32.4 |
HIP 110648 |
14.35 |
| 2026-04-08 00:00 |
22:23:30.88 |
+56:47:34.0 |
HIP 110648 |
12.56 |
| 2026-04-08 12:00 |
22:23:50.10 |
+56:50:36.6 |
HIP 110648 |
11.97 |
| 2026-04-09 00:00 |
22:24:09.10 |
+56:53:40.5 |
HIP 110648 |
12.73 |
| 2026-04-09 12:00 |
22:24:27.89 |
+56:56:45.4 |
HIP 110648 |
14.63 |
| 2026-04-10 00:00 |
22:24:46.45 |
+56:59:51.5 |
HIP 110648 |
17.29 |
| 2026-04-10 12:00 |
22:25:04.80 |
+57:02:58.7 |
HIP 110648 |
20.41 |
| 2026-04-11 00:00 |
22:25:22.92 |
+57:06:07.0 |
HIP 110497 |
22.23 |
| 2026-04-11 12:00 |
22:25:40.82 |
+57:09:16.3 |
HIP 110497 |
23.10 |
| 2026-04-12 00:00 |
22:25:58.50 |
+57:12:26.8 |
HIP 110819 |
19.38 |
| 2026-04-12 12:00 |
22:26:15.95 |
+57:15:38.3 |
HIP 110819 |
15.46 |
| 2026-04-13 00:00 |
22:26:33.17 |
+57:18:50.8 |
HIP 110819 |
11.58 |
| 2026-04-13 12:00 |
22:26:50.16 |
+57:22:04.4 |
HIP 110819 |
7.76 |
| 2026-04-14 00:00 |
22:27:06.92 |
+57:25:19.0 |
HIP 110819 |
4.20 |
| 2026-04-14 12:00 |
22:27:23.44 |
+57:28:34.7 |
HIP 110819 |
2.47 |
| 2026-04-15 00:00 |
22:27:39.74 |
+57:31:51.3 |
HIP 110819 |
5.04 |
| 2026-04-15 12:00 |
22:27:55.79 |
+57:35:08.9 |
HIP 110923 |
5.92 |
| 2026-04-16 00:00 |
22:28:11.61 |
+57:38:27.5 |
HIP 110923 |
2.08 |