| 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) |
| 2026-05-12 00:00 |
08:33:53.81 |
+30:44:32.6 |
HIP 42150 |
28.50 |
| 2026-05-12 12:00 |
08:33:54.61 |
+30:44:34.3 |
HIP 42150 |
28.36 |
| 2026-05-13 00:00 |
08:33:55.59 |
+30:44:35.7 |
HIP 42150 |
28.19 |
| 2026-05-13 12:00 |
08:33:56.75 |
+30:44:36.5 |
HIP 42150 |
28.00 |
| 2026-05-14 00:00 |
08:33:58.09 |
+30:44:36.9 |
HIP 42150 |
27.79 |
| 2026-05-14 12:00 |
08:33:59.60 |
+30:44:36.9 |
HIP 42150 |
27.57 |
| 2026-05-15 00:00 |
08:34:01.29 |
+30:44:36.4 |
HIP 42150 |
27.32 |
| 2026-05-15 12:00 |
08:34:03.15 |
+30:44:35.5 |
HIP 42150 |
27.06 |
| 2026-05-16 00:00 |
08:34:05.19 |
+30:44:34.2 |
HIP 42150 |
26.78 |
| 2026-05-16 12:00 |
08:34:07.39 |
+30:44:32.5 |
HIP 42150 |
26.48 |
| 2026-05-17 00:00 |
08:34:09.76 |
+30:44:30.3 |
HIP 42150 |
26.17 |
| 2026-05-17 12:00 |
08:34:12.30 |
+30:44:27.8 |
HIP 42150 |
25.85 |
| 2026-05-18 00:00 |
08:34:15.01 |
+30:44:24.9 |
HIP 42150 |
25.52 |
| 2026-05-18 12:00 |
08:34:17.88 |
+30:44:21.7 |
HIP 42150 |
25.18 |
| 2026-05-19 00:00 |
08:34:20.91 |
+30:44:18.0 |
HIP 42150 |
24.84 |
| 2026-05-19 12:00 |
08:34:24.10 |
+30:44:14.0 |
HIP 42150 |
24.49 |
| 2026-05-20 00:00 |
08:34:27.45 |
+30:44:09.7 |
HIP 42150 |
24.15 |
| 2026-05-20 12:00 |
08:34:30.96 |
+30:44:05.0 |
HIP 42150 |
23.81 |
| 2026-05-21 00:00 |
08:34:34.62 |
+30:44:00.0 |
HIP 42150 |
23.48 |
| 2026-05-21 12:00 |
08:34:38.44 |
+30:43:54.6 |
HIP 42150 |
23.16 |
| 2026-05-22 00:00 |
08:34:42.41 |
+30:43:49.0 |
HIP 42150 |
22.85 |
| 2026-05-22 12:00 |
08:34:46.53 |
+30:43:43.0 |
HIP 42150 |
22.57 |
| 2026-05-23 00:00 |
08:34:50.80 |
+30:43:36.7 |
HIP 42150 |
22.30 |
| 2026-05-23 12:00 |
08:34:55.21 |
+30:43:30.1 |
HIP 42150 |
22.07 |
| 2026-05-24 00:00 |
08:34:59.78 |
+30:43:23.2 |
HIP 42150 |
21.88 |
| 2026-05-24 12:00 |
08:35:04.48 |
+30:43:16.0 |
HIP 42150 |
21.72 |
| 2026-05-25 00:00 |
08:35:09.34 |
+30:43:08.6 |
HIP 42150 |
21.61 |
| 2026-05-25 12:00 |
08:35:14.33 |
+30:43:00.9 |
HIP 42150 |
21.54 |
| 2026-05-26 00:00 |
08:35:19.46 |
+30:42:52.9 |
HIP 42150 |
21.54 |
| 2026-05-26 12:00 |
08:35:24.73 |
+30:42:44.6 |
HIP 42150 |
21.59 |
| 2026-05-27 00:00 |
08:35:30.14 |
+30:42:36.1 |
HIP 42150 |
21.71 |
| 2026-05-27 12:00 |
08:35:35.68 |
+30:42:27.4 |
HIP 42150 |
21.89 |
| 2026-05-28 00:00 |
08:35:41.36 |
+30:42:18.4 |
HIP 42150 |
22.15 |
| 2026-05-28 12:00 |
08:35:47.16 |
+30:42:09.2 |
HIP 42150 |
22.48 |
| 2026-05-29 00:00 |
08:35:53.11 |
+30:41:59.7 |
HIP 42150 |
22.88 |
| 2026-05-29 12:00 |
08:35:59.18 |
+30:41:50.0 |
HIP 42150 |
23.36 |
| 2026-05-30 00:00 |
08:36:05.38 |
+30:41:40.1 |
HIP 42150 |
23.91 |
| 2026-05-30 12:00 |
08:36:11.70 |
+30:41:30.0 |
HIP 42150 |
24.54 |
| 2026-05-31 00:00 |
08:36:18.15 |
+30:41:19.7 |
HIP 42150 |
25.24 |
| 2026-05-31 12:00 |
08:36:24.73 |
+30:41:09.2 |
HIP 42150 |
26.01 |
| 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 |