| Parameter |
Value |
| Designation |
C/2025 X1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2026-12-10T22:15:00.463680Z |
| Orbit solution date (soln_date, UTC) |
2026-03-31T09:42:23Z |
| Obs used |
135 |
| NEO |
- |
| M1 |
4.700 |
| K1 |
17.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-12-12T15:00:50.889600Z |
| Discovery magnitude (MPC) |
21.04 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2026-01-06.0000000 |
| e |
0.86213785 |
| q (au) |
4.668769 |
| a (au) |
33.865486 |
| i (deg) |
36.957279 |
| Ω (om, deg) |
95.638315 |
| ω (w, deg) |
85.635574 |
| M (ma, deg) |
358.304982 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.789 + 4.173\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.789 |
| n |
4.173 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
09:48:16.72 |
+48:13:25.5 |
HIP 48013 |
15.18 |
| 2026-03-26 12:00 |
09:48:09.93 |
+48:12:59.5 |
HIP 48013 |
14.11 |
| 2026-03-27 00:00 |
09:48:03.37 |
+48:12:31.5 |
HIP 48013 |
13.07 |
| 2026-03-27 12:00 |
09:47:57.04 |
+48:12:01.4 |
HIP 48013 |
12.04 |
| 2026-03-28 00:00 |
09:47:50.93 |
+48:11:29.3 |
HIP 48013 |
11.04 |
| 2026-03-28 12:00 |
09:47:45.05 |
+48:10:55.1 |
HIP 48013 |
10.05 |
| 2026-03-29 00:00 |
09:47:39.40 |
+48:10:19.0 |
HIP 48013 |
9.09 |
| 2026-03-29 12:00 |
09:47:33.98 |
+48:09:40.9 |
HIP 48013 |
8.15 |
| 2026-03-30 00:00 |
09:47:28.80 |
+48:09:00.8 |
HIP 48013 |
7.23 |
| 2026-03-30 12:00 |
09:47:23.85 |
+48:08:18.8 |
HIP 48013 |
6.35 |
| 2026-03-31 00:00 |
09:47:19.13 |
+48:07:34.9 |
HIP 48013 |
5.51 |
| 2026-03-31 12:00 |
09:47:14.65 |
+48:06:49.0 |
HIP 48013 |
4.73 |
| 2026-04-01 00:00 |
09:47:10.40 |
+48:06:01.2 |
HIP 48013 |
4.04 |
| 2026-04-01 12:00 |
09:47:06.40 |
+48:05:11.5 |
HIP 48013 |
3.50 |
| 2026-04-02 00:00 |
09:47:02.63 |
+48:04:20.0 |
HIP 48013 |
3.19 |
| 2026-04-02 12:00 |
09:46:59.10 |
+48:03:26.6 |
HIP 48013 |
3.16 |
| 2026-04-03 00:00 |
09:46:55.82 |
+48:02:31.3 |
HIP 48013 |
3.43 |
| 2026-04-03 12:00 |
09:46:52.77 |
+48:01:34.2 |
HIP 48013 |
3.95 |
| 2026-04-04 00:00 |
09:46:49.97 |
+48:00:35.3 |
HIP 48013 |
4.64 |
| 2026-04-04 12:00 |
09:46:47.41 |
+47:59:34.6 |
HIP 48013 |
5.43 |
| 2026-04-05 00:00 |
09:46:45.09 |
+47:58:32.1 |
HIP 48013 |
6.31 |
| 2026-04-05 12:00 |
09:46:43.03 |
+47:57:27.9 |
HIP 48013 |
7.23 |
| 2026-04-06 00:00 |
09:46:41.20 |
+47:56:21.8 |
HIP 48013 |
8.20 |
| 2026-04-06 12:00 |
09:46:39.62 |
+47:55:14.1 |
HIP 48013 |
9.20 |
| 2026-04-07 00:00 |
09:46:38.29 |
+47:54:04.6 |
HIP 48013 |
10.23 |
| 2026-04-07 12:00 |
09:46:37.21 |
+47:52:53.4 |
HIP 48013 |
11.29 |
| 2026-04-08 00:00 |
09:46:36.38 |
+47:51:40.4 |
HIP 48013 |
12.37 |
| 2026-04-08 12:00 |
09:46:35.79 |
+47:50:25.8 |
HIP 48013 |
13.49 |
| 2026-04-09 00:00 |
09:46:35.46 |
+47:49:09.5 |
HIP 48013 |
14.63 |
| 2026-04-09 12:00 |
09:46:35.37 |
+47:47:51.6 |
HIP 48013 |
15.80 |
| 2026-04-10 00:00 |
09:46:35.54 |
+47:46:32.0 |
HIP 48013 |
16.99 |
| 2026-04-10 12:00 |
09:46:35.96 |
+47:45:10.8 |
HIP 48013 |
18.21 |
| 2026-04-11 00:00 |
09:46:36.62 |
+47:43:47.9 |
HIP 48013 |
19.46 |
| 2026-04-11 12:00 |
09:46:37.54 |
+47:42:23.5 |
HIP 48013 |
20.74 |
| 2026-04-12 00:00 |
09:46:38.72 |
+47:40:57.5 |
HIP 48013 |
22.05 |
| 2026-04-12 12:00 |
09:46:40.14 |
+47:39:29.9 |
HIP 48008 |
22.80 |
| 2026-04-13 00:00 |
09:46:41.82 |
+47:38:00.7 |
HIP 48008 |
21.29 |
| 2026-04-13 12:00 |
09:46:43.75 |
+47:36:30.0 |
HIP 48008 |
19.75 |
| 2026-04-14 00:00 |
09:46:45.93 |
+47:34:57.7 |
HIP 48008 |
18.17 |
| 2026-04-14 12:00 |
09:46:48.37 |
+47:33:24.0 |
HIP 48008 |
16.55 |
| 2026-04-15 00:00 |
09:46:51.06 |
+47:31:48.7 |
HIP 48008 |
14.90 |
| 2026-04-15 12:00 |
09:46:54.00 |
+47:30:11.9 |
HIP 48008 |
13.21 |
| 2026-04-16 00:00 |
09:46:57.20 |
+47:28:33.7 |
HIP 48008 |
11.49 |