| Parameter |
Value |
| Designation |
C/2025 D6 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2024-12-11T08:17:56.722560Z |
| Orbit solution date (soln_date, UTC) |
2025-10-28T16:12:42Z |
| Obs used |
144 |
| NEO |
- |
| M1 |
12.600 |
| K1 |
10.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-02-26T06:35:48.595200Z |
| Discovery magnitude (MPC) |
18.48 o |
| Discovery observatory (MPC) |
W68 · ATLAS Chile, Rio Hurtado |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2025-03-22.0000000 |
| e |
0.99797059 |
| q (au) |
2.503681 |
| a (au) |
1233.700697 |
| i (deg) |
145.789062 |
| Ω (om, deg) |
151.490101 |
| ω (w, deg) |
285.394018 |
| M (ma, deg) |
0.002289 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.398 + 4.428\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.398 |
| n |
4.428 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.943 |
| 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) |
| 2026-06-01 00:00 |
08:36:31.43 |
+30:40:58.4 |
HIP 42150 |
26.85 |
| 2026-06-01 12:00 |
08:36:38.25 |
+30:40:47.5 |
HIP 42389 |
25.84 |
| 2026-06-02 00:00 |
08:36:45.20 |
+30:40:36.4 |
HIP 42389 |
24.37 |
| 2026-06-02 12:00 |
08:36:52.26 |
+30:40:25.1 |
HIP 42389 |
22.88 |
| 2026-06-03 00:00 |
08:36:59.44 |
+30:40:13.7 |
HIP 42389 |
21.36 |
| 2026-06-03 12:00 |
08:37:06.74 |
+30:40:02.1 |
HIP 42389 |
19.83 |
| 2026-06-04 00:00 |
08:37:14.15 |
+30:39:50.3 |
HIP 42389 |
18.28 |
| 2026-06-04 12:00 |
08:37:21.68 |
+30:39:38.3 |
HIP 42389 |
16.72 |
| 2026-06-05 00:00 |
08:37:29.32 |
+30:39:26.2 |
HIP 42389 |
15.16 |
| 2026-06-05 12:00 |
08:37:37.07 |
+30:39:13.9 |
HIP 42389 |
13.58 |
| 2026-06-06 00:00 |
08:37:44.94 |
+30:39:01.5 |
HIP 42389 |
12.02 |
| 2026-06-06 12:00 |
08:37:52.91 |
+30:38:48.9 |
HIP 42389 |
10.48 |
| 2026-06-07 00:00 |
08:38:00.99 |
+30:38:36.2 |
HIP 42389 |
8.99 |
| 2026-06-07 12:00 |
08:38:09.18 |
+30:38:23.4 |
HIP 42389 |
7.59 |
| 2026-06-08 00:00 |
08:38:17.48 |
+30:38:10.4 |
HIP 42389 |
6.36 |
| 2026-06-08 12:00 |
08:38:25.88 |
+30:37:57.3 |
HIP 42389 |
5.46 |
| 2026-06-09 00:00 |
08:38:34.38 |
+30:37:44.1 |
HIP 42389 |
5.06 |
| 2026-06-09 12:00 |
08:38:42.99 |
+30:37:30.8 |
HIP 42389 |
5.32 |
| 2026-06-10 00:00 |
08:38:51.70 |
+30:37:17.4 |
HIP 42389 |
6.18 |
| 2026-06-10 12:00 |
08:39:00.50 |
+30:37:03.8 |
HIP 42389 |
7.44 |
| 2026-06-11 00:00 |
08:39:09.41 |
+30:36:50.2 |
HIP 42389 |
8.95 |
| 2026-06-11 12:00 |
08:39:18.42 |
+30:36:36.4 |
HIP 42389 |
10.61 |
| 2026-06-12 00:00 |
08:39:27.52 |
+30:36:22.6 |
HIP 42389 |
12.38 |
| 2026-06-12 12:00 |
08:39:36.72 |
+30:36:08.7 |
HIP 42389 |
14.22 |
| 2026-06-13 00:00 |
08:39:46.01 |
+30:35:54.7 |
HIP 42389 |
16.12 |
| 2026-06-13 12:00 |
08:39:55.39 |
+30:35:40.6 |
HIP 42389 |
18.06 |
| 2026-06-14 00:00 |
08:40:04.87 |
+30:35:26.5 |
HIP 42389 |
20.03 |
| 2026-06-14 12:00 |
08:40:14.44 |
+30:35:12.3 |
HIP 42389 |
22.04 |
| 2026-06-15 00:00 |
08:40:24.10 |
+30:34:58.0 |
HIP 42389 |
24.08 |
| 2026-06-15 12:00 |
08:40:33.84 |
+30:34:43.7 |
HIP 42389 |
26.15 |
| 2026-06-16 00:00 |
08:40:43.67 |
+30:34:29.3 |
HIP 42389 |
28.24 |
| 2026-06-16 12:00 |
08:40:53.59 |
+30:34:14.9 |
HIP 42389 |
30.35 |
| 2026-06-17 00:00 |
08:41:03.59 |
+30:34:00.4 |
HIP 42389 |
32.48 |
| 2026-06-17 12:00 |
08:41:13.68 |
+30:33:45.9 |
HIP 42658 |
34.54 |
| 2026-06-18 00:00 |
08:41:23.85 |
+30:33:31.4 |
HIP 42658 |
34.01 |
| 2026-06-18 12:00 |
08:41:34.09 |
+30:33:16.9 |
HIP 42658 |
33.63 |
| 2026-06-19 00:00 |
08:41:44.42 |
+30:33:02.3 |
HIP 42658 |
33.39 |
| 2026-06-19 12:00 |
08:41:54.82 |
+30:32:47.7 |
HIP 42658 |
33.30 |
| 2026-06-20 00:00 |
08:42:05.30 |
+30:32:33.1 |
HIP 42658 |
33.36 |
| 2026-06-20 12:00 |
08:42:15.86 |
+30:32:18.6 |
HIP 42658 |
33.58 |
| 2026-06-21 00:00 |
08:42:26.49 |
+30:32:04.0 |
HIP 42658 |
33.97 |
| 2026-06-21 12:00 |
08:42:37.20 |
+30:31:49.4 |
HIP 42658 |
34.50 |
| 2026-06-22 00:00 |
08:42:47.97 |
+30:31:34.8 |
HIP 42954 |
34.58 |