| 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) |
| 2026-05-12 00:00 |
04:52:56.03 |
-43:06:21.7 |
HIP 22674 |
4.65 |
| 2026-05-12 12:00 |
04:53:36.07 |
-43:10:52.9 |
HIP 22770 |
10.61 |
| 2026-05-13 00:00 |
04:54:16.34 |
-43:15:26.9 |
HIP 22770 |
15.16 |
| 2026-05-13 12:00 |
04:54:56.85 |
-43:20:03.9 |
HIP 22971 |
18.76 |
| 2026-05-14 00:00 |
04:55:37.60 |
-43:24:43.7 |
HIP 22971 |
10.47 |
| 2026-05-14 12:00 |
04:56:18.59 |
-43:29:26.5 |
HIP 22971 |
4.57 |
| 2026-05-15 00:00 |
04:56:59.82 |
-43:34:12.1 |
HIP 22971 |
9.41 |
| 2026-05-15 12:00 |
04:57:41.28 |
-43:39:00.7 |
HIP 23158 |
13.77 |
| 2026-05-16 00:00 |
04:58:22.98 |
-43:43:52.2 |
HIP 23158 |
6.37 |
| 2026-05-16 12:00 |
04:59:04.92 |
-43:48:46.6 |
HIP 23158 |
7.31 |
| 2026-05-17 00:00 |
04:59:47.10 |
-43:53:43.9 |
HIP 23158 |
15.20 |
| 2026-05-17 12:00 |
05:00:29.52 |
-43:58:44.2 |
HIP 23158 |
24.01 |
| 2026-05-18 00:00 |
05:01:12.17 |
-44:03:47.4 |
HIP 23158 |
33.05 |
| 2026-05-18 12:00 |
05:01:55.07 |
-44:08:53.6 |
HIP 23630 |
31.28 |
| 2026-05-19 00:00 |
05:02:38.20 |
-44:14:02.7 |
HIP 23630 |
23.85 |
| 2026-05-19 12:00 |
05:03:21.57 |
-44:19:14.7 |
HIP 23630 |
18.22 |
| 2026-05-20 00:00 |
05:04:05.18 |
-44:24:29.7 |
HIP 23630 |
16.48 |
| 2026-05-20 12:00 |
05:04:49.02 |
-44:29:47.6 |
HIP 23630 |
19.76 |
| 2026-05-21 00:00 |
05:05:33.11 |
-44:35:08.5 |
HIP 23713 |
12.16 |
| 2026-05-21 12:00 |
05:06:17.43 |
-44:40:32.3 |
HIP 23713 |
7.48 |
| 2026-05-22 00:00 |
05:07:01.99 |
-44:45:59.1 |
HIP 23833 |
5.39 |
| 2026-05-22 12:00 |
05:07:46.79 |
-44:51:28.8 |
HIP 23833 |
4.29 |
| 2026-05-23 00:00 |
05:08:31.84 |
-44:57:01.4 |
HIP 23833 |
14.00 |
| 2026-05-23 12:00 |
05:09:17.12 |
-45:02:36.9 |
HIP 24060 |
14.54 |
| 2026-05-24 00:00 |
05:10:02.64 |
-45:08:15.4 |
HIP 24023 |
16.04 |
| 2026-05-24 12:00 |
05:10:48.41 |
-45:13:56.8 |
HIP 24023 |
14.85 |
| 2026-05-25 00:00 |
05:11:34.42 |
-45:19:41.1 |
HIP 24186 |
19.42 |
| 2026-05-25 12:00 |
05:12:20.67 |
-45:25:28.4 |
HIP 24395 |
19.47 |
| 2026-05-26 00:00 |
05:13:07.16 |
-45:31:18.5 |
HIP 24395 |
9.75 |
| 2026-05-26 12:00 |
05:13:53.90 |
-45:37:11.5 |
HIP 24395 |
3.51 |
| 2026-05-27 00:00 |
05:14:40.89 |
-45:43:07.5 |
HIP 24432 |
4.65 |
| 2026-05-27 12:00 |
05:15:28.12 |
-45:49:06.3 |
HIP 24432 |
10.02 |
| 2026-05-28 00:00 |
05:16:15.60 |
-45:55:08.1 |
HIP 24603 |
3.88 |
| 2026-05-28 12:00 |
05:17:03.33 |
-46:01:12.7 |
HIP 24603 |
7.77 |
| 2026-05-29 00:00 |
05:17:51.31 |
-46:07:20.2 |
HIP 24603 |
17.87 |
| 2026-05-29 12:00 |
05:18:39.54 |
-46:13:30.5 |
HIP 24911 |
26.84 |
| 2026-05-30 00:00 |
05:19:28.02 |
-46:19:43.8 |
HIP 24911 |
16.82 |
| 2026-05-30 12:00 |
05:20:16.76 |
-46:25:59.9 |
HIP 24911 |
7.86 |
| 2026-05-31 00:00 |
05:21:05.75 |
-46:32:18.9 |
HIP 24911 |
7.79 |
| 2026-05-31 12:00 |
05:21:54.99 |
-46:38:40.7 |
HIP 24911 |
16.81 |
| 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 |