| Parameter |
Value |
| Designation |
C/2025 Q1 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2024-07-12T01:27:00.011520Z |
| Orbit solution date (soln_date, UTC) |
2025-12-12T11:12:31Z |
| Obs used |
24 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
8.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-08-27T05:43:50.505600Z |
| Discovery magnitude (MPC) |
19.88 o |
| Discovery observatory (MPC) |
W68 · ATLAS Chile, Rio Hurtado |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2025-01-29.0000000 |
| e |
0.99127748 |
| q (au) |
10.099968 |
| a (au) |
1157.918555 |
| i (deg) |
66.152955 |
| Ω (om, deg) |
326.964441 |
| ω (w, deg) |
280.236072 |
| M (ma, deg) |
0.005026 |
Magnitude
Scatter + Global Linear
$$
M_a = (-1.324 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-1.324 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.502 |
| k |
1.000 |
| 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 |
21:56:35.75 |
-62:14:00.2 |
HIP 108195 |
23.05 |
| 2026-03-26 12:00 |
21:56:53.40 |
-62:13:39.8 |
HIP 108594 |
22.31 |
| 2026-03-27 00:00 |
21:57:10.93 |
-62:13:20.2 |
HIP 108594 |
20.28 |
| 2026-03-27 12:00 |
21:57:28.35 |
-62:13:01.6 |
HIP 108594 |
18.27 |
| 2026-03-28 00:00 |
21:57:45.65 |
-62:12:43.8 |
HIP 108594 |
16.29 |
| 2026-03-28 12:00 |
21:58:02.85 |
-62:12:26.8 |
HIP 108594 |
14.34 |
| 2026-03-29 00:00 |
21:58:19.93 |
-62:12:10.8 |
HIP 108594 |
12.45 |
| 2026-03-29 12:00 |
21:58:36.90 |
-62:11:55.6 |
HIP 108594 |
10.61 |
| 2026-03-30 00:00 |
21:58:53.75 |
-62:11:41.3 |
HIP 108594 |
8.86 |
| 2026-03-30 12:00 |
21:59:10.48 |
-62:11:27.8 |
HIP 108594 |
7.25 |
| 2026-03-31 00:00 |
21:59:27.10 |
-62:11:15.2 |
HIP 108594 |
5.88 |
| 2026-03-31 12:00 |
21:59:43.61 |
-62:11:03.5 |
HIP 108594 |
4.94 |
| 2026-04-01 00:00 |
22:00:00.00 |
-62:10:52.6 |
HIP 108610 |
4.28 |
| 2026-04-01 12:00 |
22:00:16.26 |
-62:10:42.6 |
HIP 108610 |
4.16 |
| 2026-04-02 00:00 |
22:00:32.41 |
-62:10:33.4 |
HIP 108610 |
4.85 |
| 2026-04-02 12:00 |
22:00:48.44 |
-62:10:25.1 |
HIP 108610 |
6.07 |
| 2026-04-03 00:00 |
22:01:04.34 |
-62:10:17.7 |
HIP 108610 |
7.57 |
| 2026-04-03 12:00 |
22:01:20.13 |
-62:10:11.1 |
HIP 108610 |
9.19 |
| 2026-04-04 00:00 |
22:01:35.80 |
-62:10:05.4 |
HIP 108610 |
10.87 |
| 2026-04-04 12:00 |
22:01:51.34 |
-62:10:00.6 |
HIP 108610 |
12.59 |
| 2026-04-05 00:00 |
22:02:06.76 |
-62:09:56.6 |
HIP 108610 |
14.32 |
| 2026-04-05 12:00 |
22:02:22.06 |
-62:09:53.4 |
HIP 108610 |
16.05 |
| 2026-04-06 00:00 |
22:02:37.23 |
-62:09:51.1 |
HIP 108610 |
17.79 |
| 2026-04-06 12:00 |
22:02:52.28 |
-62:09:49.7 |
HIP 108610 |
19.51 |
| 2026-04-07 00:00 |
22:03:07.20 |
-62:09:49.1 |
HIP 108944 |
19.34 |
| 2026-04-07 12:00 |
22:03:21.99 |
-62:09:49.4 |
HIP 108944 |
18.67 |
| 2026-04-08 00:00 |
22:03:36.66 |
-62:09:50.5 |
HIP 108944 |
18.15 |
| 2026-04-08 12:00 |
22:03:51.19 |
-62:09:52.4 |
HIP 108944 |
17.80 |
| 2026-04-09 00:00 |
22:04:05.60 |
-62:09:55.3 |
HIP 108944 |
17.62 |
| 2026-04-09 12:00 |
22:04:19.88 |
-62:09:58.9 |
HIP 108944 |
17.62 |
| 2026-04-10 00:00 |
22:04:34.03 |
-62:10:03.4 |
HIP 108944 |
17.80 |
| 2026-04-10 12:00 |
22:04:48.04 |
-62:10:08.8 |
HIP 108944 |
18.13 |
| 2026-04-11 00:00 |
22:05:01.92 |
-62:10:15.0 |
HIP 108944 |
18.61 |
| 2026-04-11 12:00 |
22:05:15.67 |
-62:10:22.0 |
HIP 108944 |
19.23 |
| 2026-04-12 00:00 |
22:05:29.29 |
-62:10:29.9 |
HIP 108944 |
19.96 |
| 2026-04-12 12:00 |
22:05:42.77 |
-62:10:38.6 |
HIP 108944 |
20.80 |
| 2026-04-13 00:00 |
22:05:56.11 |
-62:10:48.1 |
HIP 108944 |
21.73 |
| 2026-04-13 12:00 |
22:06:09.32 |
-62:10:58.5 |
HIP 108944 |
22.72 |
| 2026-04-14 00:00 |
22:06:22.38 |
-62:11:09.7 |
HIP 108944 |
23.78 |
| 2026-04-14 12:00 |
22:06:35.31 |
-62:11:21.8 |
HIP 108944 |
24.89 |
| 2026-04-15 00:00 |
22:06:48.10 |
-62:11:34.6 |
HIP 108944 |
26.04 |
| 2026-04-15 12:00 |
22:07:00.75 |
-62:11:48.3 |
HIP 108944 |
27.23 |
| 2026-04-16 00:00 |
22:07:13.26 |
-62:12:02.8 |
HIP 108944 |
28.44 |