C/2025 Y3 (PANSTARRS)
| 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) |
| 2026-02-03 00:00 |
04:27:28.12 |
-38:47:51.0 |
HIP 20863 |
9.24 |
| 2026-02-03 12:00 |
04:26:42.83 |
-38:49:26.6 |
HIP 20863 |
17.98 |
| 2026-02-04 00:00 |
04:25:58.41 |
-38:50:57.3 |
HIP 20863 |
26.69 |
| 2026-02-04 12:00 |
04:25:14.86 |
-38:52:23.2 |
HIP 20496 |
19.44 |
| 2026-02-05 00:00 |
04:24:32.16 |
-38:53:44.4 |
HIP 20496 |
11.27 |
| 2026-02-05 12:00 |
04:23:50.33 |
-38:55:01.2 |
HIP 20496 |
4.31 |
| 2026-02-06 00:00 |
04:23:09.35 |
-38:56:13.7 |
HIP 20496 |
6.60 |
| 2026-02-06 12:00 |
04:22:29.21 |
-38:57:21.9 |
HIP 20496 |
13.91 |
| 2026-02-07 00:00 |
04:21:49.92 |
-38:58:26.1 |
HIP 20496 |
21.45 |
| 2026-02-07 12:00 |
04:21:11.47 |
-38:59:26.4 |
HIP 20496 |
28.91 |
| 2026-02-08 00:00 |
04:20:33.85 |
-39:00:22.8 |
HIP 20496 |
36.23 |
| 2026-02-08 12:00 |
04:19:57.05 |
-39:01:15.6 |
HIP 19989 |
33.30 |
| 2026-02-09 00:00 |
04:19:21.08 |
-39:02:04.9 |
HIP 19989 |
27.10 |
| 2026-02-09 12:00 |
04:18:45.93 |
-39:02:50.8 |
HIP 19989 |
21.52 |
| 2026-02-10 00:00 |
04:18:11.58 |
-39:03:33.4 |
HIP 19989 |
16.99 |
| 2026-02-10 12:00 |
04:17:38.04 |
-39:04:12.8 |
HIP 19989 |
14.30 |
| 2026-02-11 00:00 |
04:17:05.30 |
-39:04:49.2 |
HIP 19923 |
13.71 |
| 2026-02-11 12:00 |
04:16:33.36 |
-39:05:22.7 |
HIP 19923 |
12.36 |
| 2026-02-12 00:00 |
04:16:02.20 |
-39:05:53.4 |
HIP 19923 |
13.87 |
| 2026-02-12 12:00 |
04:15:31.83 |
-39:06:21.3 |
HIP 19794 |
14.10 |
| 2026-02-13 00:00 |
04:15:02.23 |
-39:06:46.8 |
HIP 19794 |
10.31 |
| 2026-02-13 12:00 |
04:14:33.40 |
-39:07:09.7 |
HIP 19794 |
8.93 |
| 2026-02-14 00:00 |
04:14:05.34 |
-39:07:30.3 |
HIP 19794 |
10.67 |
| 2026-02-14 12:00 |
04:13:38.03 |
-39:07:48.6 |
HIP 19794 |
14.27 |
| 2026-02-15 00:00 |
04:13:11.47 |
-39:08:04.8 |
HIP 19794 |
18.56 |
| 2026-02-15 12:00 |
04:12:45.66 |
-39:08:19.0 |
HIP 19794 |
23.06 |
| 2026-02-16 00:00 |
04:12:20.59 |
-39:08:31.2 |
HIP 19794 |
27.59 |
| 2026-02-16 12:00 |
04:11:56.25 |
-39:08:41.5 |
HIP 19794 |
32.08 |
| 2026-02-17 00:00 |
04:11:32.64 |
-39:08:50.2 |
HIP 19794 |
36.49 |
| 2026-02-17 12:00 |
04:11:09.74 |
-39:08:57.1 |
HIP 19406 |
34.60 |
| 2026-02-18 00:00 |
04:10:47.57 |
-39:09:02.5 |
HIP 19406 |
32.29 |
| 2026-02-18 12:00 |
04:10:26.09 |
-39:09:06.5 |
HIP 19406 |
30.45 |
| 2026-02-19 00:00 |
04:10:05.32 |
-39:09:09.1 |
HIP 19406 |
29.12 |
| 2026-02-19 12:00 |
04:09:45.24 |
-39:09:10.3 |
HIP 19406 |
28.30 |
| 2026-02-20 00:00 |
04:09:25.85 |
-39:09:10.4 |
HIP 19406 |
27.99 |
| 2026-02-20 12:00 |
04:09:07.13 |
-39:09:09.4 |
HIP 19406 |
28.15 |
| 2026-02-21 00:00 |
04:08:49.10 |
-39:09:07.4 |
HIP 19238 |
26.54 |
| 2026-02-21 12:00 |
04:08:31.72 |
-39:09:04.4 |
HIP 19238 |
24.64 |
| 2026-02-22 00:00 |
04:08:15.01 |
-39:09:00.5 |
HIP 19238 |
23.14 |
| 2026-02-22 12:00 |
04:07:58.96 |
-39:08:55.8 |
HIP 19238 |
22.06 |
| 2026-02-23 00:00 |
04:07:43.54 |
-39:08:50.4 |
HIP 19238 |
21.42 |
| 2026-02-23 12:00 |
04:07:28.77 |
-39:08:44.4 |
HIP 19126 |
19.19 |
| 2026-02-24 00:00 |
04:07:14.64 |
-39:08:37.8 |
HIP 19126 |
16.76 |