| Parameter |
Value |
| Designation |
C/2025 Y3 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2026-01-13T16:51:06.096960Z |
| Orbit solution date (soln_date, UTC) |
2026-01-20T12:12:02Z |
| Obs used |
27 |
| NEO |
- |
| M1 |
16.800 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-12-27T09:18:59.788800Z |
| Discovery magnitude (MPC) |
21.65 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2026-01-02.0000000 |
| e |
1.00074191 |
| q (au) |
2.227313 |
| a (au) |
-3002.143709 |
| i (deg) |
89.548987 |
| Ω (om, deg) |
272.966956 |
| ω (w, deg) |
219.383051 |
| M (ma, deg) |
-0.000070 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.597 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.597 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
05:22:44.50 |
-46:45:05.3 |
HIP 25206 |
19.64 |
| 2026-06-01 12:00 |
05:23:34.26 |
-46:51:32.8 |
HIP 25358 |
23.31 |
| 2026-06-02 00:00 |
05:24:24.28 |
-46:58:03.2 |
HIP 25358 |
12.57 |
| 2026-06-02 12:00 |
05:25:14.57 |
-47:04:36.3 |
HIP 25358 |
1.78 |
| 2026-06-03 00:00 |
05:26:05.12 |
-47:11:12.3 |
HIP 25358 |
9.06 |
| 2026-06-03 12:00 |
05:26:55.93 |
-47:17:51.1 |
HIP 25358 |
19.95 |
| 2026-06-04 00:00 |
05:27:47.01 |
-47:24:32.7 |
HIP 25746 |
28.90 |
| 2026-06-04 12:00 |
05:28:38.35 |
-47:31:17.1 |
HIP 25797 |
27.14 |
| 2026-06-05 00:00 |
05:29:29.97 |
-47:38:04.3 |
HIP 25797 |
28.03 |
| 2026-06-05 12:00 |
05:30:21.86 |
-47:44:54.3 |
HIP 25968 |
24.03 |
| 2026-06-06 00:00 |
05:31:14.01 |
-47:51:47.0 |
HIP 25968 |
13.03 |
| 2026-06-06 12:00 |
05:32:06.45 |
-47:58:42.6 |
HIP 25968 |
3.21 |
| 2026-06-07 00:00 |
05:32:59.16 |
-48:05:40.9 |
HIP 26040 |
9.98 |
| 2026-06-07 12:00 |
05:33:52.14 |
-48:12:41.9 |
HIP 26040 |
17.45 |
| 2026-06-08 00:00 |
05:34:45.41 |
-48:19:45.7 |
HIP 26347 |
18.61 |
| 2026-06-08 12:00 |
05:35:38.95 |
-48:26:52.2 |
HIP 26347 |
13.64 |
| 2026-06-09 00:00 |
05:36:32.78 |
-48:34:01.5 |
HIP 26347 |
16.95 |
| 2026-06-09 12:00 |
05:37:26.89 |
-48:41:13.5 |
HIP 26347 |
25.57 |
| 2026-06-10 00:00 |
05:38:21.29 |
-48:48:28.2 |
HIP 26578 |
35.77 |
| 2026-06-10 12:00 |
05:39:15.98 |
-48:55:45.6 |
HIP 26685 |
37.92 |
| 2026-06-11 00:00 |
05:40:10.96 |
-49:03:05.7 |
HIP 26685 |
29.30 |
| 2026-06-11 12:00 |
05:41:06.22 |
-49:10:28.5 |
HIP 26685 |
23.38 |
| 2026-06-12 00:00 |
05:42:01.78 |
-49:17:53.9 |
HIP 26685 |
22.48 |
| 2026-06-12 12:00 |
05:42:57.64 |
-49:25:22.0 |
HIP 27055 |
19.61 |
| 2026-06-13 00:00 |
05:43:53.79 |
-49:32:52.8 |
HIP 26975 |
18.20 |
| 2026-06-13 12:00 |
05:44:50.24 |
-49:40:26.2 |
HIP 26975 |
16.86 |
| 2026-06-14 00:00 |
05:45:46.99 |
-49:48:02.2 |
HIP 26975 |
22.77 |
| 2026-06-14 12:00 |
05:46:44.04 |
-49:55:40.9 |
HIP 27367 |
12.14 |
| 2026-06-15 00:00 |
05:47:41.39 |
-50:03:22.1 |
HIP 27367 |
1.05 |
| 2026-06-15 12:00 |
05:48:39.05 |
-50:11:05.9 |
HIP 27367 |
12.00 |
| 2026-06-16 00:00 |
05:49:37.02 |
-50:18:52.3 |
HIP 27647 |
15.43 |
| 2026-06-16 12:00 |
05:50:35.29 |
-50:26:41.2 |
HIP 27647 |
12.65 |
| 2026-06-17 00:00 |
05:51:33.87 |
-50:34:32.6 |
HIP 27622 |
10.23 |
| 2026-06-17 12:00 |
05:52:32.77 |
-50:42:26.5 |
HIP 27711 |
10.49 |
| 2026-06-18 00:00 |
05:53:31.97 |
-50:50:23.0 |
HIP 27711 |
13.83 |
| 2026-06-18 12:00 |
05:54:31.50 |
-50:58:21.8 |
HIP 27978 |
4.63 |
| 2026-06-19 00:00 |
05:55:31.34 |
-51:06:23.1 |
HIP 27978 |
8.59 |
| 2026-06-19 12:00 |
05:56:31.50 |
-51:14:26.9 |
HIP 27978 |
20.83 |
| 2026-06-20 00:00 |
05:57:31.99 |
-51:22:33.0 |
HIP 28322 |
16.76 |
| 2026-06-20 12:00 |
05:58:32.80 |
-51:30:41.5 |
HIP 28322 |
17.88 |
| 2026-06-21 00:00 |
05:59:33.93 |
-51:38:52.3 |
HIP 28462 |
14.34 |
| 2026-06-21 12:00 |
06:00:35.40 |
-51:47:05.4 |
HIP 28462 |
19.01 |
| 2026-06-22 00:00 |
06:01:37.20 |
-51:55:20.8 |
HIP 28652 |
17.29 |