| 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) |
| 2026-07-29 00:00 |
09:24:40.42 |
+14:13:33.0 |
HIP 46019 |
23.03 |
| 2026-07-29 12:00 |
09:25:33.42 |
+14:09:22.0 |
HIP 46345 |
22.03 |
| 2026-07-30 00:00 |
09:26:26.37 |
+14:05:10.3 |
HIP 46345 |
14.96 |
| 2026-07-30 12:00 |
09:27:19.27 |
+14:00:57.9 |
HIP 46345 |
18.08 |
| 2026-07-31 00:00 |
09:28:12.12 |
+13:56:44.8 |
HIP 46415 |
12.48 |
| 2026-07-31 12:00 |
09:29:04.91 |
+13:52:31.0 |
HIP 46415 |
18.48 |
| 2026-08-01 00:00 |
09:29:57.66 |
+13:48:16.6 |
HIP 46650 |
21.39 |
| 2026-08-01 12:00 |
09:30:50.35 |
+13:44:01.4 |
HIP 46650 |
14.41 |
| 2026-08-02 00:00 |
09:31:42.99 |
+13:39:45.6 |
HIP 46680 |
14.69 |
| 2026-08-02 12:00 |
09:32:35.57 |
+13:35:29.2 |
HIP 46680 |
23.80 |
| 2026-08-03 00:00 |
09:33:28.11 |
+13:31:12.1 |
HIP 46680 |
35.77 |
| 2026-08-03 12:00 |
09:34:20.59 |
+13:26:54.3 |
HIP 47149 |
31.80 |
| 2026-08-04 00:00 |
09:35:13.03 |
+13:22:35.9 |
HIP 47149 |
18.40 |
| 2026-08-04 12:00 |
09:36:05.41 |
+13:18:16.8 |
HIP 47149 |
5.34 |
| 2026-08-05 00:00 |
09:36:57.74 |
+13:13:57.2 |
HIP 47149 |
8.96 |
| 2026-08-05 12:00 |
09:37:50.01 |
+13:09:36.8 |
HIP 47149 |
22.22 |
| 2026-08-06 00:00 |
09:38:42.24 |
+13:05:15.9 |
HIP 47388 |
15.96 |
| 2026-08-06 12:00 |
09:39:34.41 |
+13:00:54.3 |
HIP 47468 |
15.00 |
| 2026-08-07 00:00 |
09:40:26.54 |
+12:56:32.1 |
HIP 47468 |
7.03 |
| 2026-08-07 12:00 |
09:41:18.61 |
+12:52:09.3 |
HIP 47551 |
5.21 |
| 2026-08-08 00:00 |
09:42:10.63 |
+12:47:45.9 |
HIP 47551 |
9.92 |
| 2026-08-08 12:00 |
09:43:02.60 |
+12:43:21.9 |
HIP 47683 |
8.81 |
| 2026-08-09 00:00 |
09:43:54.51 |
+12:38:57.4 |
HIP 47683 |
8.45 |
| 2026-08-09 12:00 |
09:44:46.38 |
+12:34:32.2 |
HIP 47771 |
11.59 |
| 2026-08-10 00:00 |
09:45:38.19 |
+12:30:06.4 |
HIP 47771 |
19.30 |
| 2026-08-10 12:00 |
09:46:29.95 |
+12:25:40.1 |
HIP 47771 |
31.13 |
| 2026-08-11 00:00 |
09:47:21.65 |
+12:21:13.3 |
HIP 48142 |
24.19 |
| 2026-08-11 12:00 |
09:48:13.30 |
+12:16:45.8 |
HIP 48161 |
15.85 |
| 2026-08-12 00:00 |
09:49:04.90 |
+12:12:17.8 |
HIP 48161 |
6.62 |
| 2026-08-12 12:00 |
09:49:56.45 |
+12:07:49.3 |
HIP 48161 |
13.94 |
| 2026-08-13 00:00 |
09:50:47.94 |
+12:03:20.3 |
HIP 48298 |
12.80 |
| 2026-08-13 12:00 |
09:51:39.38 |
+11:58:50.7 |
HIP 48298 |
14.80 |
| 2026-08-14 00:00 |
09:52:30.76 |
+11:54:20.6 |
HIP 48298 |
25.12 |
| 2026-08-14 12:00 |
09:53:22.09 |
+11:49:50.0 |
HIP 48298 |
37.40 |
| 2026-08-15 00:00 |
09:54:13.37 |
+11:45:18.9 |
HIP 48654 |
35.15 |
| 2026-08-15 12:00 |
09:55:04.59 |
+11:40:47.3 |
HIP 48654 |
26.92 |
| 2026-08-16 00:00 |
09:55:55.75 |
+11:36:15.2 |
HIP 48654 |
23.86 |
| 2026-08-16 12:00 |
09:56:46.86 |
+11:31:42.6 |
HIP 48654 |
27.72 |
| 2026-08-17 00:00 |
09:57:37.92 |
+11:27:09.5 |
HIP 48988 |
31.47 |
| 2026-08-17 12:00 |
09:58:28.92 |
+11:22:36.0 |
HIP 48988 |
22.39 |
| 2026-08-18 00:00 |
09:59:19.86 |
+11:18:02.0 |
HIP 48988 |
19.12 |
| 2026-08-18 12:00 |
10:00:10.75 |
+11:13:27.6 |
HIP 48988 |
24.15 |
| 2026-08-19 00:00 |
10:01:01.58 |
+11:08:52.7 |
HIP 48988 |
33.97 |