| Parameter |
Value |
| Designation |
C/2025 B1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-06-26T18:23:26.652480Z |
| Orbit solution date (soln_date, UTC) |
2026-03-07T14:43:13Z |
| Obs used |
50 |
| NEO |
- |
| M1 |
11.800 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-01-20T05:46:10.819200Z |
| Discovery magnitude (MPC) |
20.72 w |
| Discovery observatory (MPC) |
F52 · Pan-STARRS 2, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2025-01-22.0000000 |
| e |
1.00271821 |
| q (au) |
3.529741 |
| a (au) |
-1298.553960 |
| i (deg) |
39.649466 |
| Ω (om, deg) |
102.844475 |
| ω (w, deg) |
23.544686 |
| M (ma, deg) |
-0.003281 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.806 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.806 |
| n |
6.000 |
| gf |
0.997 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
9.997 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
12:31:12.24 |
+45:08:18.1 |
HIP 61132 |
6.98 |
| 2026-05-12 12:00 |
12:31:09.24 |
+45:04:47.8 |
HIP 61132 |
10.15 |
| 2026-05-13 00:00 |
12:31:06.45 |
+45:01:15.6 |
HIP 61132 |
13.51 |
| 2026-05-13 12:00 |
12:31:03.90 |
+44:57:41.6 |
HIP 61132 |
16.98 |
| 2026-05-14 00:00 |
12:31:01.57 |
+44:54:05.8 |
HIP 61132 |
20.50 |
| 2026-05-14 12:00 |
12:30:59.47 |
+44:50:28.3 |
HIP 61132 |
24.07 |
| 2026-05-15 00:00 |
12:30:57.60 |
+44:46:49.0 |
HIP 61132 |
27.68 |
| 2026-05-15 12:00 |
12:30:55.95 |
+44:43:07.9 |
HIP 60832 |
30.67 |
| 2026-05-16 00:00 |
12:30:54.53 |
+44:39:25.1 |
HIP 61057 |
28.10 |
| 2026-05-16 12:00 |
12:30:53.34 |
+44:35:40.6 |
HIP 61057 |
24.35 |
| 2026-05-17 00:00 |
12:30:52.38 |
+44:31:54.5 |
HIP 61057 |
20.59 |
| 2026-05-17 12:00 |
12:30:51.65 |
+44:28:06.7 |
HIP 61057 |
16.79 |
| 2026-05-18 00:00 |
12:30:51.14 |
+44:24:17.4 |
HIP 61057 |
12.97 |
| 2026-05-18 12:00 |
12:30:50.86 |
+44:20:26.4 |
HIP 61057 |
9.12 |
| 2026-05-19 00:00 |
12:30:50.81 |
+44:16:33.8 |
HIP 61057 |
5.26 |
| 2026-05-19 12:00 |
12:30:50.98 |
+44:12:39.7 |
HIP 61057 |
1.39 |
| 2026-05-20 00:00 |
12:30:51.38 |
+44:08:44.1 |
HIP 61057 |
2.60 |
| 2026-05-20 12:00 |
12:30:52.01 |
+44:04:47.1 |
HIP 61057 |
6.54 |
| 2026-05-21 00:00 |
12:30:52.86 |
+44:00:48.5 |
HIP 61057 |
10.51 |
| 2026-05-21 12:00 |
12:30:53.94 |
+43:56:48.5 |
HIP 61057 |
14.52 |
| 2026-05-22 00:00 |
12:30:55.24 |
+43:52:47.1 |
HIP 61057 |
18.54 |
| 2026-05-22 12:00 |
12:30:56.76 |
+43:48:44.3 |
HIP 61057 |
22.60 |
| 2026-05-23 00:00 |
12:30:58.51 |
+43:44:40.1 |
HIP 61163 |
19.18 |
| 2026-05-23 12:00 |
12:31:00.48 |
+43:40:34.6 |
HIP 61163 |
15.77 |
| 2026-05-24 00:00 |
12:31:02.67 |
+43:36:27.7 |
HIP 61163 |
12.72 |
| 2026-05-24 12:00 |
12:31:05.08 |
+43:32:19.6 |
HIP 61163 |
10.41 |
| 2026-05-25 00:00 |
12:31:07.71 |
+43:28:10.1 |
HIP 61163 |
9.42 |
| 2026-05-25 12:00 |
12:31:10.56 |
+43:23:59.5 |
HIP 61163 |
10.18 |
| 2026-05-26 00:00 |
12:31:13.63 |
+43:19:47.5 |
HIP 61163 |
12.40 |
| 2026-05-26 12:00 |
12:31:16.91 |
+43:15:34.4 |
HIP 61190 |
11.60 |
| 2026-05-27 00:00 |
12:31:20.41 |
+43:11:20.1 |
HIP 61190 |
10.42 |
| 2026-05-27 12:00 |
12:31:24.13 |
+43:07:04.6 |
HIP 61190 |
10.89 |
| 2026-05-28 00:00 |
12:31:28.06 |
+43:02:48.0 |
HIP 61190 |
12.86 |
| 2026-05-28 12:00 |
12:31:32.20 |
+42:58:30.2 |
HIP 61190 |
15.80 |
| 2026-05-29 00:00 |
12:31:36.56 |
+42:54:11.3 |
HIP 61190 |
19.29 |
| 2026-05-29 12:00 |
12:31:41.12 |
+42:49:51.4 |
HIP 61116 |
18.09 |
| 2026-05-30 00:00 |
12:31:45.90 |
+42:45:30.3 |
HIP 61116 |
13.89 |
| 2026-05-30 12:00 |
12:31:50.89 |
+42:41:08.2 |
HIP 61116 |
9.91 |
| 2026-05-31 00:00 |
12:31:56.08 |
+42:36:45.1 |
HIP 61116 |
6.59 |
| 2026-05-31 12:00 |
12:32:01.49 |
+42:32:21.0 |
HIP 61116 |
5.42 |
| 2026-06-01 00:00 |
12:32:07.09 |
+42:27:55.8 |
HIP 61116 |
7.53 |
| 2026-06-01 12:00 |
12:32:12.91 |
+42:23:29.7 |
HIP 61116 |
11.23 |
| 2026-06-02 00:00 |
12:32:18.93 |
+42:19:02.6 |
HIP 61116 |
15.43 |