| Parameter |
Value |
| Designation |
C/2025 K2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-10-25T07:48:17.305920Z |
| Orbit solution date (soln_date, UTC) |
2025-08-12T09:42:16Z |
| Obs used |
26 |
| NEO |
- |
| M1 |
7.400 |
| K1 |
21.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-05-29T12:48:33.840000Z |
| Discovery magnitude (MPC) |
20.47 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2025-06-09.0000000 |
| e |
0.88709889 |
| q (au) |
2.863643 |
| a (au) |
25.364173 |
| i (deg) |
113.978010 |
| Ω (om, deg) |
113.828014 |
| ω (w, deg) |
232.466816 |
| M (ma, deg) |
358.932730 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.125 + 4.640\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.125 |
| n |
4.640 |
| gf |
0.993 |
| gb |
-0.976 |
| k |
0.800 |
| 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) |
| 2026-06-01 00:00 |
07:54:11.09 |
-40:54:26.0 |
HIP 38610 |
3.64 |
| 2026-06-01 12:00 |
07:54:39.67 |
-40:44:57.1 |
HIP 38610 |
7.30 |
| 2026-06-02 00:00 |
07:55:08.24 |
-40:35:32.8 |
HIP 38799 |
14.90 |
| 2026-06-02 12:00 |
07:55:36.81 |
-40:26:13.1 |
HIP 38799 |
12.85 |
| 2026-06-03 00:00 |
07:56:05.36 |
-40:16:58.2 |
HIP 38799 |
18.39 |
| 2026-06-03 12:00 |
07:56:33.91 |
-40:07:47.9 |
HIP 38907 |
13.72 |
| 2026-06-04 00:00 |
07:57:02.45 |
-39:58:42.2 |
HIP 38907 |
12.00 |
| 2026-06-04 12:00 |
07:57:30.98 |
-39:49:41.1 |
HIP 38955 |
15.13 |
| 2026-06-05 00:00 |
07:57:59.49 |
-39:40:44.7 |
HIP 38955 |
4.65 |
| 2026-06-05 12:00 |
07:58:27.99 |
-39:31:52.8 |
HIP 38955 |
5.78 |
| 2026-06-06 00:00 |
07:58:56.49 |
-39:23:05.5 |
HIP 39028 |
3.03 |
| 2026-06-06 12:00 |
07:59:24.97 |
-39:14:22.7 |
HIP 39061 |
3.50 |
| 2026-06-07 00:00 |
07:59:53.43 |
-39:05:44.5 |
HIP 39061 |
13.00 |
| 2026-06-07 12:00 |
08:00:21.88 |
-38:57:10.8 |
HIP 39161 |
5.32 |
| 2026-06-08 00:00 |
08:00:50.32 |
-38:48:41.7 |
HIP 39161 |
4.90 |
| 2026-06-08 12:00 |
08:01:18.74 |
-38:40:17.0 |
HIP 39161 |
14.94 |
| 2026-06-09 00:00 |
08:01:47.15 |
-38:31:56.8 |
HIP 39408 |
19.77 |
| 2026-06-09 12:00 |
08:02:15.54 |
-38:23:41.1 |
HIP 39390 |
16.04 |
| 2026-06-10 00:00 |
08:02:43.91 |
-38:15:29.8 |
HIP 39390 |
6.39 |
| 2026-06-10 12:00 |
08:03:12.27 |
-38:07:23.0 |
HIP 39390 |
4.43 |
| 2026-06-11 00:00 |
08:03:40.61 |
-37:59:20.6 |
HIP 39390 |
13.79 |
| 2026-06-11 12:00 |
08:04:08.93 |
-37:51:22.6 |
HIP 39390 |
23.44 |
| 2026-06-12 00:00 |
08:04:37.24 |
-37:43:29.0 |
HIP 39390 |
33.08 |
| 2026-06-12 12:00 |
08:05:05.52 |
-37:35:39.7 |
HIP 39763 |
31.72 |
| 2026-06-13 00:00 |
08:05:33.78 |
-37:27:54.8 |
HIP 39763 |
24.73 |
| 2026-06-13 12:00 |
08:06:02.03 |
-37:20:14.3 |
HIP 39763 |
19.97 |
| 2026-06-14 00:00 |
08:06:30.25 |
-37:12:38.1 |
HIP 39763 |
19.09 |
| 2026-06-14 12:00 |
08:06:58.45 |
-37:05:06.2 |
HIP 39763 |
22.47 |
| 2026-06-15 00:00 |
08:07:26.62 |
-36:57:38.6 |
HIP 39965 |
27.25 |
| 2026-06-15 12:00 |
08:07:54.78 |
-36:50:15.3 |
HIP 39965 |
20.52 |
| 2026-06-16 00:00 |
08:08:22.91 |
-36:42:56.2 |
HIP 39965 |
16.44 |
| 2026-06-16 12:00 |
08:08:51.01 |
-36:35:41.4 |
HIP 39814 |
13.65 |
| 2026-06-17 00:00 |
08:09:19.08 |
-36:28:30.8 |
HIP 39814 |
14.68 |
| 2026-06-17 12:00 |
08:09:47.13 |
-36:21:24.4 |
HIP 39814 |
20.28 |
| 2026-06-18 00:00 |
08:10:15.16 |
-36:14:22.2 |
HIP 39814 |
27.76 |
| 2026-06-18 12:00 |
08:10:43.15 |
-36:07:24.2 |
HIP 40144 |
25.37 |
| 2026-06-19 00:00 |
08:11:11.11 |
-36:00:30.2 |
HIP 40144 |
16.51 |
| 2026-06-19 12:00 |
08:11:39.05 |
-35:53:40.4 |
HIP 40144 |
7.85 |
| 2026-06-20 00:00 |
08:12:06.95 |
-35:46:54.7 |
HIP 40144 |
2.81 |
| 2026-06-20 12:00 |
08:12:34.82 |
-35:40:13.1 |
HIP 40162 |
6.63 |
| 2026-06-21 00:00 |
08:13:02.66 |
-35:33:35.5 |
HIP 40225 |
10.13 |
| 2026-06-21 12:00 |
08:13:30.47 |
-35:27:02.0 |
HIP 40225 |
7.99 |
| 2026-06-22 00:00 |
08:13:58.24 |
-35:20:32.4 |
HIP 40307 |
8.19 |