| 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 |
1.000 |
| 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) |
| 2026-06-01 00:00 |
22:31:29.24 |
+63:18:12.8 |
HIP 111221 |
7.59 |
| 2026-06-01 12:00 |
22:31:14.68 |
+63:21:51.6 |
HIP 111166 |
9.50 |
| 2026-06-02 00:00 |
22:30:59.68 |
+63:25:29.6 |
HIP 111166 |
6.13 |
| 2026-06-02 12:00 |
22:30:44.26 |
+63:29:06.9 |
HIP 111166 |
4.17 |
| 2026-06-03 00:00 |
22:30:28.41 |
+63:32:43.3 |
HIP 111166 |
5.45 |
| 2026-06-03 12:00 |
22:30:12.13 |
+63:36:19.0 |
HIP 111166 |
8.65 |
| 2026-06-04 00:00 |
22:29:55.41 |
+63:39:53.9 |
HIP 111166 |
12.36 |
| 2026-06-04 12:00 |
22:29:38.25 |
+63:43:27.8 |
HIP 111174 |
12.46 |
| 2026-06-05 00:00 |
22:29:20.65 |
+63:47:01.0 |
HIP 111174 |
13.22 |
| 2026-06-05 12:00 |
22:29:02.62 |
+63:50:33.2 |
HIP 110841 |
13.14 |
| 2026-06-06 00:00 |
22:28:44.14 |
+63:54:04.4 |
HIP 110841 |
9.76 |
| 2026-06-06 12:00 |
22:28:25.22 |
+63:57:34.7 |
HIP 110841 |
7.10 |
| 2026-06-07 00:00 |
22:28:05.85 |
+64:01:04.0 |
HIP 110919 |
4.31 |
| 2026-06-07 12:00 |
22:27:46.03 |
+64:04:32.3 |
HIP 110919 |
3.70 |
| 2026-06-08 00:00 |
22:27:25.76 |
+64:07:59.6 |
HIP 110919 |
6.53 |
| 2026-06-08 12:00 |
22:27:05.04 |
+64:11:25.7 |
HIP 110919 |
10.28 |
| 2026-06-09 00:00 |
22:26:43.87 |
+64:14:50.8 |
HIP 110919 |
14.25 |
| 2026-06-09 12:00 |
22:26:22.25 |
+64:18:14.7 |
HIP 110919 |
18.31 |
| 2026-06-10 00:00 |
22:26:00.17 |
+64:21:37.5 |
HIP 110919 |
22.40 |
| 2026-06-10 12:00 |
22:25:37.63 |
+64:24:59.0 |
HIP 110452 |
22.07 |
| 2026-06-11 00:00 |
22:25:14.63 |
+64:28:19.4 |
HIP 110452 |
20.78 |
| 2026-06-11 12:00 |
22:24:51.17 |
+64:31:38.4 |
HIP 110452 |
20.24 |
| 2026-06-12 00:00 |
22:24:27.25 |
+64:34:56.2 |
HIP 110540 |
18.77 |
| 2026-06-12 12:00 |
22:24:02.87 |
+64:38:12.7 |
HIP 110540 |
14.94 |
| 2026-06-13 00:00 |
22:23:38.02 |
+64:41:27.8 |
HIP 110540 |
11.38 |
| 2026-06-13 12:00 |
22:23:12.71 |
+64:44:41.5 |
HIP 110540 |
8.46 |
| 2026-06-14 00:00 |
22:22:46.93 |
+64:47:53.8 |
HIP 110540 |
7.05 |
| 2026-06-14 12:00 |
22:22:20.69 |
+64:51:04.6 |
HIP 110540 |
8.01 |
| 2026-06-15 00:00 |
22:21:53.98 |
+64:54:14.0 |
HIP 110540 |
10.73 |
| 2026-06-15 12:00 |
22:21:26.81 |
+64:57:21.8 |
HIP 110540 |
14.25 |
| 2026-06-16 00:00 |
22:20:59.17 |
+65:00:28.1 |
HIP 110214 |
16.10 |
| 2026-06-16 12:00 |
22:20:31.06 |
+65:03:32.8 |
HIP 110214 |
17.41 |
| 2026-06-17 00:00 |
22:20:02.48 |
+65:06:35.8 |
HIP 110122 |
18.23 |
| 2026-06-17 12:00 |
22:19:33.44 |
+65:09:37.2 |
HIP 110122 |
19.47 |
| 2026-06-18 00:00 |
22:19:03.93 |
+65:12:37.0 |
HIP 110007 |
20.79 |
| 2026-06-18 12:00 |
22:18:33.95 |
+65:15:35.0 |
HIP 110007 |
16.49 |
| 2026-06-19 00:00 |
22:18:03.51 |
+65:18:31.2 |
HIP 110007 |
12.21 |
| 2026-06-19 12:00 |
22:17:32.60 |
+65:21:25.6 |
HIP 110007 |
7.98 |
| 2026-06-20 00:00 |
22:17:01.23 |
+65:24:18.3 |
HIP 110007 |
4.01 |
| 2026-06-20 12:00 |
22:16:29.40 |
+65:27:09.0 |
HIP 110007 |
2.57 |
| 2026-06-21 00:00 |
22:15:57.11 |
+65:29:57.9 |
HIP 110007 |
5.96 |
| 2026-06-21 12:00 |
22:15:24.35 |
+65:32:44.9 |
HIP 110007 |
10.16 |
| 2026-06-22 00:00 |
22:14:51.13 |
+65:35:29.9 |
HIP 109798 |
11.87 |