| 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
$$
M_a = (10.716 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.716 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-0.622 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
13:01:36.17 |
+33:07:50.4 |
HIP 63747 |
31.37 |
| 2026-07-29 12:00 |
13:01:58.60 |
+33:03:02.5 |
HIP 63747 |
25.27 |
| 2026-07-30 00:00 |
13:02:21.12 |
+32:58:15.0 |
HIP 63747 |
19.55 |
| 2026-07-30 12:00 |
13:02:43.71 |
+32:53:27.8 |
HIP 63747 |
14.69 |
| 2026-07-31 00:00 |
13:03:06.40 |
+32:48:41.0 |
HIP 63747 |
11.81 |
| 2026-07-31 12:00 |
13:03:29.16 |
+32:43:54.6 |
HIP 63747 |
12.39 |
| 2026-08-01 00:00 |
13:03:52.00 |
+32:39:08.6 |
HIP 63747 |
16.09 |
| 2026-08-01 12:00 |
13:04:14.93 |
+32:34:23.0 |
HIP 63747 |
21.34 |
| 2026-08-02 00:00 |
13:04:37.93 |
+32:29:37.8 |
HIP 63941 |
22.27 |
| 2026-08-02 12:00 |
13:05:01.01 |
+32:24:53.0 |
HIP 63941 |
16.07 |
| 2026-08-03 00:00 |
13:05:24.17 |
+32:20:08.6 |
HIP 63941 |
10.63 |
| 2026-08-03 12:00 |
13:05:47.41 |
+32:15:24.7 |
HIP 63941 |
7.73 |
| 2026-08-04 00:00 |
13:06:10.73 |
+32:10:41.1 |
HIP 63941 |
9.97 |
| 2026-08-04 12:00 |
13:06:34.12 |
+32:05:58.0 |
HIP 63941 |
15.24 |
| 2026-08-05 00:00 |
13:06:57.58 |
+32:01:15.3 |
HIP 64107 |
16.70 |
| 2026-08-05 12:00 |
13:07:21.13 |
+31:56:33.0 |
HIP 64107 |
13.21 |
| 2026-08-06 00:00 |
13:07:44.74 |
+31:51:51.2 |
HIP 64107 |
12.79 |
| 2026-08-06 12:00 |
13:08:08.43 |
+31:47:09.9 |
HIP 64107 |
15.71 |
| 2026-08-07 00:00 |
13:08:32.20 |
+31:42:29.0 |
HIP 64107 |
20.60 |
| 2026-08-07 12:00 |
13:08:56.03 |
+31:37:48.5 |
HIP 64232 |
19.80 |
| 2026-08-08 00:00 |
13:09:19.94 |
+31:33:08.6 |
HIP 64232 |
13.07 |
| 2026-08-08 12:00 |
13:09:43.92 |
+31:28:29.1 |
HIP 64232 |
6.70 |
| 2026-08-09 00:00 |
13:10:07.97 |
+31:23:50.0 |
HIP 64232 |
3.86 |
| 2026-08-09 12:00 |
13:10:32.09 |
+31:19:11.5 |
HIP 64232 |
9.01 |
| 2026-08-10 00:00 |
13:10:56.28 |
+31:14:33.5 |
HIP 64232 |
15.62 |
| 2026-08-10 12:00 |
13:11:20.54 |
+31:09:55.9 |
HIP 64232 |
22.44 |
| 2026-08-11 00:00 |
13:11:44.86 |
+31:05:18.9 |
HIP 64232 |
29.34 |
| 2026-08-11 12:00 |
13:12:09.25 |
+31:00:42.4 |
HIP 64581 |
26.57 |
| 2026-08-12 00:00 |
13:12:33.71 |
+30:56:06.4 |
HIP 64581 |
22.57 |
| 2026-08-12 12:00 |
13:12:58.24 |
+30:51:30.9 |
HIP 64581 |
20.24 |
| 2026-08-13 00:00 |
13:13:22.83 |
+30:46:56.0 |
HIP 64581 |
20.16 |
| 2026-08-13 12:00 |
13:13:47.48 |
+30:42:21.6 |
HIP 64581 |
22.36 |
| 2026-08-14 00:00 |
13:14:12.20 |
+30:37:47.8 |
HIP 64581 |
26.28 |
| 2026-08-14 12:00 |
13:14:36.98 |
+30:33:14.5 |
HIP 64748 |
28.88 |
| 2026-08-15 00:00 |
13:15:01.82 |
+30:28:41.8 |
HIP 64748 |
29.17 |
| 2026-08-15 12:00 |
13:15:26.73 |
+30:24:09.7 |
HIP 64827 |
27.74 |
| 2026-08-16 00:00 |
13:15:51.69 |
+30:19:38.1 |
HIP 64827 |
25.83 |
| 2026-08-16 12:00 |
13:16:16.71 |
+30:15:07.1 |
HIP 64827 |
25.75 |
| 2026-08-17 00:00 |
13:16:41.79 |
+30:10:36.7 |
HIP 64827 |
27.51 |
| 2026-08-17 12:00 |
13:17:06.93 |
+30:06:06.9 |
HIP 64827 |
30.81 |
| 2026-08-18 00:00 |
13:17:32.13 |
+30:01:37.7 |
HIP 64827 |
35.21 |
| 2026-08-18 12:00 |
13:17:57.38 |
+29:57:09.2 |
HIP 64977 |
28.58 |
| 2026-08-19 00:00 |
13:18:22.69 |
+29:52:41.2 |
HIP 64977 |
22.11 |