| 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) |
| 2026-07-29 00:00 |
07:37:47.18 |
-63:12:56.1 |
HIP 37050 |
8.23 |
| 2026-07-29 12:00 |
07:39:26.14 |
-63:22:18.8 |
HIP 37257 |
4.22 |
| 2026-07-30 00:00 |
07:41:05.83 |
-63:31:40.4 |
HIP 37555 |
9.44 |
| 2026-07-30 12:00 |
07:42:46.24 |
-63:41:01.0 |
HIP 37555 |
12.07 |
| 2026-07-31 00:00 |
07:44:27.40 |
-63:50:20.5 |
HIP 37931 |
18.26 |
| 2026-07-31 12:00 |
07:46:09.31 |
-63:59:38.8 |
HIP 37931 |
4.08 |
| 2026-08-01 00:00 |
07:47:51.99 |
-64:08:55.8 |
HIP 37931 |
11.13 |
| 2026-08-01 12:00 |
07:49:35.42 |
-64:18:11.6 |
HIP 38258 |
10.53 |
| 2026-08-02 00:00 |
07:51:19.64 |
-64:27:25.9 |
HIP 38407 |
11.05 |
| 2026-08-02 12:00 |
07:53:04.64 |
-64:36:38.9 |
HIP 38736 |
18.66 |
| 2026-08-03 00:00 |
07:54:50.43 |
-64:45:50.4 |
HIP 38736 |
7.12 |
| 2026-08-03 12:00 |
07:56:37.03 |
-64:55:00.3 |
HIP 38736 |
13.37 |
| 2026-08-04 00:00 |
07:58:24.44 |
-65:04:08.6 |
HIP 39146 |
18.52 |
| 2026-08-04 12:00 |
08:00:12.66 |
-65:13:15.3 |
HIP 39065 |
13.53 |
| 2026-08-05 00:00 |
08:02:01.72 |
-65:22:20.2 |
HIP 39379 |
7.02 |
| 2026-08-05 12:00 |
08:03:51.61 |
-65:31:23.3 |
HIP 39379 |
12.85 |
| 2026-08-06 00:00 |
08:05:42.34 |
-65:40:24.5 |
HIP 39756 |
21.38 |
| 2026-08-06 12:00 |
08:07:33.93 |
-65:49:23.8 |
HIP 39756 |
9.20 |
| 2026-08-07 00:00 |
08:09:26.38 |
-65:58:21.1 |
HIP 39756 |
11.63 |
| 2026-08-07 12:00 |
08:11:19.70 |
-66:07:16.4 |
HIP 40204 |
18.13 |
| 2026-08-08 00:00 |
08:13:13.90 |
-66:16:09.5 |
HIP 40204 |
7.96 |
| 2026-08-08 12:00 |
08:15:08.99 |
-66:25:00.5 |
HIP 40377 |
9.28 |
| 2026-08-09 00:00 |
08:17:04.97 |
-66:33:49.2 |
HIP 40630 |
5.19 |
| 2026-08-09 12:00 |
08:19:01.85 |
-66:42:35.6 |
HIP 40630 |
9.41 |
| 2026-08-10 00:00 |
08:20:59.65 |
-66:51:19.6 |
HIP 40837 |
22.25 |
| 2026-08-10 12:00 |
08:22:58.36 |
-67:00:01.2 |
HIP 41237 |
16.98 |
| 2026-08-11 00:00 |
08:24:58.00 |
-67:08:40.2 |
HIP 41301 |
6.09 |
| 2026-08-11 12:00 |
08:26:58.57 |
-67:17:16.7 |
HIP 41301 |
8.82 |
| 2026-08-12 00:00 |
08:29:00.08 |
-67:25:50.5 |
HIP 41667 |
17.94 |
| 2026-08-12 12:00 |
08:31:02.54 |
-67:34:21.6 |
HIP 41667 |
27.08 |
| 2026-08-13 00:00 |
08:33:05.96 |
-67:42:49.9 |
HIP 42226 |
34.10 |
| 2026-08-13 12:00 |
08:35:10.34 |
-67:51:15.3 |
HIP 42557 |
30.08 |
| 2026-08-14 00:00 |
08:37:15.70 |
-67:59:37.8 |
HIP 42557 |
20.91 |
| 2026-08-14 12:00 |
08:39:22.03 |
-68:07:57.3 |
HIP 42557 |
19.75 |
| 2026-08-15 00:00 |
08:41:29.34 |
-68:16:13.7 |
HIP 42650 |
9.47 |
| 2026-08-15 12:00 |
08:43:37.65 |
-68:24:26.9 |
HIP 42650 |
11.55 |
| 2026-08-16 00:00 |
08:45:46.95 |
-68:32:36.9 |
HIP 43226 |
15.67 |
| 2026-08-16 12:00 |
08:47:57.26 |
-68:40:43.7 |
HIP 43226 |
2.13 |
| 2026-08-17 00:00 |
08:50:08.58 |
-68:48:47.0 |
HIP 43563 |
12.72 |
| 2026-08-17 12:00 |
08:52:20.92 |
-68:56:46.9 |
HIP 43617 |
10.96 |
| 2026-08-18 00:00 |
08:54:34.28 |
-69:04:43.3 |
HIP 43617 |
8.70 |
| 2026-08-18 12:00 |
08:56:48.67 |
-69:12:36.1 |
HIP 44025 |
6.71 |
| 2026-08-19 00:00 |
08:59:04.09 |
-69:20:25.3 |
HIP 44025 |
12.48 |