| Parameter |
Value |
| Designation |
P/2025 W4 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2025-10-04T11:24:31.605120Z |
| Orbit solution date (soln_date, UTC) |
2026-03-11T21:13:02Z |
| Obs used |
104 |
| NEO |
- |
| M1 |
17.300 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-11-23T12:20:09.600000Z |
| Discovery magnitude (MPC) |
20.65 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2025-12-01.0000000 |
| e |
0.21117858 |
| q (au) |
2.034369 |
| a (au) |
2.578999 |
| i (deg) |
1.298188 |
| Ω (om, deg) |
237.120950 |
| ω (w, deg) |
172.279158 |
| M (ma, deg) |
13.689301 |
Magnitude
Scatter + Global Linear
$$
M_a = (20.000 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
20.000 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-0.654 |
| k |
0.916 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
07:37:13.99 |
+20:34:23.6 |
HIP 37054 |
6.92 |
| 2026-06-01 12:00 |
07:38:11.34 |
+20:32:11.0 |
HIP 37054 |
18.28 |
| 2026-06-02 00:00 |
07:39:08.67 |
+20:29:57.1 |
HIP 37298 |
20.96 |
| 2026-06-02 12:00 |
07:40:05.99 |
+20:27:42.0 |
HIP 37438 |
14.78 |
| 2026-06-03 00:00 |
07:41:03.30 |
+20:25:25.6 |
HIP 37438 |
1.26 |
| 2026-06-03 12:00 |
07:42:00.59 |
+20:23:07.9 |
HIP 37438 |
12.47 |
| 2026-06-04 00:00 |
07:42:57.86 |
+20:20:49.0 |
HIP 37722 |
19.84 |
| 2026-06-04 12:00 |
07:43:55.12 |
+20:18:28.8 |
HIP 37722 |
7.74 |
| 2026-06-05 00:00 |
07:44:52.36 |
+20:16:07.3 |
HIP 37811 |
4.89 |
| 2026-06-05 12:00 |
07:45:49.58 |
+20:13:44.6 |
HIP 37811 |
10.79 |
| 2026-06-06 00:00 |
07:46:46.79 |
+20:11:20.7 |
HIP 38082 |
23.48 |
| 2026-06-06 12:00 |
07:47:43.98 |
+20:08:55.5 |
HIP 38082 |
15.22 |
| 2026-06-07 00:00 |
07:48:41.15 |
+20:06:29.0 |
HIP 38082 |
16.86 |
| 2026-06-07 12:00 |
07:49:38.30 |
+20:04:01.3 |
HIP 38163 |
18.78 |
| 2026-06-08 00:00 |
07:50:35.44 |
+20:01:32.4 |
HIP 38308 |
24.62 |
| 2026-06-08 12:00 |
07:51:32.55 |
+19:59:02.2 |
HIP 38501 |
24.59 |
| 2026-06-09 00:00 |
07:52:29.64 |
+19:56:30.8 |
HIP 38501 |
16.42 |
| 2026-06-09 12:00 |
07:53:26.72 |
+19:53:58.2 |
HIP 38501 |
17.53 |
| 2026-06-10 00:00 |
07:54:23.77 |
+19:51:24.3 |
HIP 38722 |
17.98 |
| 2026-06-10 12:00 |
07:55:20.80 |
+19:48:49.2 |
HIP 38722 |
6.17 |
| 2026-06-11 00:00 |
07:56:17.81 |
+19:46:12.9 |
HIP 38814 |
8.75 |
| 2026-06-11 12:00 |
07:57:14.80 |
+19:43:35.4 |
HIP 38814 |
13.61 |
| 2026-06-12 00:00 |
07:58:11.76 |
+19:40:56.6 |
HIP 38814 |
25.83 |
| 2026-06-12 12:00 |
07:59:08.70 |
+19:38:16.7 |
HIP 39180 |
25.72 |
| 2026-06-13 00:00 |
08:00:05.62 |
+19:35:35.5 |
HIP 39180 |
16.70 |
| 2026-06-13 12:00 |
08:01:02.51 |
+19:32:53.1 |
HIP 39180 |
16.44 |
| 2026-06-14 00:00 |
08:01:59.38 |
+19:30:09.5 |
HIP 39296 |
14.14 |
| 2026-06-14 12:00 |
08:02:56.22 |
+19:27:24.8 |
HIP 39296 |
20.74 |
| 2026-06-15 00:00 |
08:03:53.04 |
+19:24:38.8 |
HIP 39499 |
24.51 |
| 2026-06-15 12:00 |
08:04:49.82 |
+19:21:51.7 |
HIP 39499 |
26.56 |
| 2026-06-16 00:00 |
08:05:46.59 |
+19:19:03.3 |
HIP 39535 |
31.99 |
| 2026-06-16 12:00 |
08:06:43.32 |
+19:16:13.8 |
HIP 39816 |
20.41 |
| 2026-06-17 00:00 |
08:07:40.02 |
+19:13:23.2 |
HIP 39816 |
6.78 |
| 2026-06-17 12:00 |
08:08:36.69 |
+19:10:31.3 |
HIP 39816 |
7.05 |
| 2026-06-18 00:00 |
08:09:33.34 |
+19:07:38.3 |
HIP 39991 |
8.19 |
| 2026-06-18 12:00 |
08:10:29.95 |
+19:04:44.2 |
HIP 39991 |
7.01 |
| 2026-06-19 00:00 |
08:11:26.53 |
+19:01:48.9 |
HIP 40202 |
17.61 |
| 2026-06-19 12:00 |
08:12:23.08 |
+18:58:52.4 |
HIP 40202 |
5.95 |
| 2026-06-20 00:00 |
08:13:19.59 |
+18:55:54.8 |
HIP 40202 |
11.62 |
| 2026-06-20 12:00 |
08:14:16.07 |
+18:52:56.1 |
HIP 40202 |
24.69 |
| 2026-06-21 00:00 |
08:15:12.52 |
+18:49:56.2 |
HIP 40483 |
13.68 |
| 2026-06-21 12:00 |
08:16:08.93 |
+18:46:55.3 |
HIP 40483 |
5.84 |
| 2026-06-22 00:00 |
08:17:05.30 |
+18:43:53.2 |
HIP 40483 |
15.99 |