| 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 |
1.000 |
| gb |
-0.654 |
| k |
0.914 |
| 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) |
| 2026-05-12 00:00 |
06:58:57.10 |
+21:44:55.7 |
HIP 33599 |
8.14 |
| 2026-05-12 12:00 |
06:59:54.35 |
+21:43:35.9 |
HIP 33599 |
15.99 |
| 2026-05-13 00:00 |
07:00:51.63 |
+21:42:14.8 |
HIP 33890 |
18.06 |
| 2026-05-13 12:00 |
07:01:48.93 |
+21:40:52.3 |
HIP 33890 |
8.00 |
| 2026-05-14 00:00 |
07:02:46.25 |
+21:39:28.5 |
HIP 33890 |
12.65 |
| 2026-05-14 12:00 |
07:03:43.58 |
+21:38:03.3 |
HIP 33890 |
24.80 |
| 2026-05-15 00:00 |
07:04:40.93 |
+21:36:36.8 |
HIP 33992 |
33.53 |
| 2026-05-15 12:00 |
07:05:38.30 |
+21:35:08.9 |
HIP 34218 |
35.40 |
| 2026-05-16 00:00 |
07:06:35.69 |
+21:33:39.7 |
HIP 34418 |
30.10 |
| 2026-05-16 12:00 |
07:07:33.09 |
+21:32:09.1 |
HIP 34418 |
24.03 |
| 2026-05-17 00:00 |
07:08:30.50 |
+21:30:37.2 |
HIP 34418 |
24.71 |
| 2026-05-17 12:00 |
07:09:27.92 |
+21:29:03.9 |
HIP 34608 |
16.82 |
| 2026-05-18 00:00 |
07:10:25.36 |
+21:27:29.3 |
HIP 34690 |
10.46 |
| 2026-05-18 12:00 |
07:11:22.80 |
+21:25:53.4 |
HIP 34690 |
7.29 |
| 2026-05-19 00:00 |
07:12:20.26 |
+21:24:16.1 |
HIP 34856 |
6.82 |
| 2026-05-19 12:00 |
07:13:17.72 |
+21:22:37.5 |
HIP 34856 |
7.46 |
| 2026-05-20 00:00 |
07:14:15.19 |
+21:20:57.5 |
HIP 34856 |
20.69 |
| 2026-05-20 12:00 |
07:15:12.67 |
+21:19:16.2 |
HIP 34856 |
34.13 |
| 2026-05-21 00:00 |
07:16:10.15 |
+21:17:33.6 |
HIP 35280 |
36.57 |
| 2026-05-21 12:00 |
07:17:07.63 |
+21:15:49.7 |
HIP 35280 |
31.26 |
| 2026-05-22 00:00 |
07:18:05.12 |
+21:14:04.4 |
HIP 35459 |
22.75 |
| 2026-05-22 12:00 |
07:19:02.60 |
+21:12:17.8 |
HIP 35521 |
13.04 |
| 2026-05-23 00:00 |
07:20:00.09 |
+21:10:29.8 |
HIP 35521 |
3.06 |
| 2026-05-23 12:00 |
07:20:57.58 |
+21:08:40.6 |
HIP 35673 |
13.75 |
| 2026-05-24 00:00 |
07:21:55.06 |
+21:06:50.0 |
HIP 35703 |
1.90 |
| 2026-05-24 12:00 |
07:22:52.55 |
+21:04:58.1 |
HIP 35703 |
12.66 |
| 2026-05-25 00:00 |
07:23:50.03 |
+21:03:04.9 |
HIP 35914 |
15.95 |
| 2026-05-25 12:00 |
07:24:47.50 |
+21:01:10.4 |
HIP 35914 |
15.21 |
| 2026-05-26 00:00 |
07:25:44.97 |
+20:59:14.6 |
HIP 35914 |
23.99 |
| 2026-05-26 12:00 |
07:26:42.44 |
+20:57:17.4 |
HIP 36035 |
31.73 |
| 2026-05-27 00:00 |
07:27:39.90 |
+20:55:19.0 |
HIP 36369 |
21.23 |
| 2026-05-27 12:00 |
07:28:37.35 |
+20:53:19.3 |
HIP 36369 |
7.93 |
| 2026-05-28 00:00 |
07:29:34.79 |
+20:51:18.2 |
HIP 36369 |
6.56 |
| 2026-05-28 12:00 |
07:30:32.23 |
+20:49:15.9 |
HIP 36468 |
4.63 |
| 2026-05-29 00:00 |
07:31:29.66 |
+20:47:12.3 |
HIP 36468 |
17.50 |
| 2026-05-29 12:00 |
07:32:27.07 |
+20:45:07.4 |
HIP 36506 |
29.74 |
| 2026-05-30 00:00 |
07:33:24.48 |
+20:43:01.2 |
HIP 36789 |
25.81 |
| 2026-05-30 12:00 |
07:34:21.88 |
+20:40:53.7 |
HIP 36894 |
24.30 |
| 2026-05-31 00:00 |
07:35:19.26 |
+20:38:44.9 |
HIP 36894 |
19.83 |
| 2026-05-31 12:00 |
07:36:16.63 |
+20:36:34.9 |
HIP 37054 |
11.48 |
| 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 |