| Parameter |
Value |
| Designation |
P/2025 C1 (ATLAS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2025-02-06T12:52:50.154240Z |
| Orbit solution date (soln_date, UTC) |
2025-09-30T13:39:40Z |
| Obs used |
385 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
20.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2025-02-02T15:11:23.596800Z |
| Discovery magnitude (MPC) |
18.47 c |
| Discovery observatory (MPC) |
T05 · ATLAS-HKO, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2025-02-27.0000000 |
| e |
0.34537178 |
| q (au) |
2.746051 |
| a (au) |
4.194826 |
| i (deg) |
7.517505 |
| Ω (om, deg) |
9.104185 |
| ω (w, deg) |
186.793260 |
| M (ma, deg) |
2.347518 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.324 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.324 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.997 |
| 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) |
| 2026-09-20 00:00 |
19:36:28.94 |
-29:29:47.4 |
HIP 96486 |
9.05 |
| 2026-09-20 12:00 |
19:36:31.77 |
-29:28:32.8 |
HIP 96486 |
9.77 |
| 2026-09-21 00:00 |
19:36:34.87 |
-29:27:17.6 |
HIP 96486 |
10.60 |
| 2026-09-21 12:00 |
19:36:38.24 |
-29:26:02.0 |
HIP 96486 |
11.54 |
| 2026-09-22 00:00 |
19:36:41.87 |
-29:24:45.9 |
HIP 96486 |
12.57 |
| 2026-09-22 12:00 |
19:36:45.76 |
-29:23:29.3 |
HIP 96486 |
13.69 |
| 2026-09-23 00:00 |
19:36:49.92 |
-29:22:12.2 |
HIP 96486 |
14.89 |
| 2026-09-23 12:00 |
19:36:54.33 |
-29:20:54.7 |
HIP 96486 |
16.16 |
| 2026-09-24 00:00 |
19:36:59.01 |
-29:19:36.7 |
HIP 96486 |
17.50 |
| 2026-09-24 12:00 |
19:37:03.94 |
-29:18:18.2 |
HIP 96486 |
18.90 |
| 2026-09-25 00:00 |
19:37:09.14 |
-29:16:59.3 |
HIP 96486 |
20.36 |
| 2026-09-25 12:00 |
19:37:14.58 |
-29:15:40.0 |
HIP 96486 |
21.89 |
| 2026-09-26 00:00 |
19:37:20.29 |
-29:14:20.2 |
HIP 96486 |
23.46 |
| 2026-09-26 12:00 |
19:37:26.24 |
-29:13:00.0 |
HIP 96566 |
24.73 |
| 2026-09-27 00:00 |
19:37:32.45 |
-29:11:39.3 |
HIP 96566 |
23.13 |
| 2026-09-27 12:00 |
19:37:38.91 |
-29:10:18.2 |
HIP 96566 |
21.56 |
| 2026-09-28 00:00 |
19:37:45.63 |
-29:08:56.7 |
HIP 96566 |
20.05 |
| 2026-09-28 12:00 |
19:37:52.59 |
-29:07:34.7 |
HIP 96566 |
18.62 |
| 2026-09-29 00:00 |
19:37:59.79 |
-29:06:12.4 |
HIP 96566 |
17.31 |
| 2026-09-29 12:00 |
19:38:07.25 |
-29:04:49.6 |
HIP 96566 |
16.18 |
| 2026-09-30 00:00 |
19:38:14.95 |
-29:03:26.4 |
HIP 96566 |
15.27 |
| 2026-09-30 12:00 |
19:38:22.89 |
-29:02:02.8 |
HIP 96566 |
14.65 |
| 2026-10-01 00:00 |
19:38:31.08 |
-29:00:38.8 |
HIP 96566 |
14.38 |
| 2026-10-01 12:00 |
19:38:39.51 |
-28:59:14.4 |
HIP 96566 |
14.50 |
| 2026-10-02 00:00 |
19:38:48.18 |
-28:57:49.7 |
HIP 96566 |
15.02 |
| 2026-10-02 12:00 |
19:38:57.09 |
-28:56:24.5 |
HIP 96566 |
15.92 |
| 2026-10-03 00:00 |
19:39:06.24 |
-28:54:58.9 |
HIP 96566 |
17.17 |
| 2026-10-03 12:00 |
19:39:15.63 |
-28:53:32.9 |
HIP 96644 |
17.64 |
| 2026-10-04 00:00 |
19:39:25.26 |
-28:52:06.6 |
HIP 96644 |
16.92 |
| 2026-10-04 12:00 |
19:39:35.12 |
-28:50:39.8 |
HIP 96644 |
16.59 |
| 2026-10-05 00:00 |
19:39:45.21 |
-28:49:12.7 |
HIP 96644 |
16.70 |
| 2026-10-05 12:00 |
19:39:55.54 |
-28:47:45.2 |
HIP 96644 |
17.25 |
| 2026-10-06 00:00 |
19:40:06.10 |
-28:46:17.3 |
HIP 96644 |
18.22 |
| 2026-10-06 12:00 |
19:40:16.90 |
-28:44:49.0 |
HIP 96644 |
19.58 |
| 2026-10-07 00:00 |
19:40:27.92 |
-28:43:20.4 |
HIP 96899 |
19.76 |
| 2026-10-07 12:00 |
19:40:39.17 |
-28:41:51.4 |
HIP 96899 |
18.22 |
| 2026-10-08 00:00 |
19:40:50.65 |
-28:40:22.0 |
HIP 96899 |
17.01 |
| 2026-10-08 12:00 |
19:41:02.35 |
-28:38:52.2 |
HIP 96899 |
16.21 |
| 2026-10-09 00:00 |
19:41:14.28 |
-28:37:22.1 |
HIP 96899 |
15.91 |
| 2026-10-09 12:00 |
19:41:26.44 |
-28:35:51.6 |
HIP 96899 |
16.16 |
| 2026-10-10 00:00 |
19:41:38.81 |
-28:34:20.7 |
HIP 96899 |
16.97 |
| 2026-10-10 12:00 |
19:41:51.41 |
-28:32:49.5 |
HIP 96899 |
18.29 |
| 2026-10-11 00:00 |
19:42:04.23 |
-28:31:17.9 |
HIP 96899 |
20.03 |