| 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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
12:32:25.15 |
+42:14:34.6 |
HIP 61116 |
19.84 |
| 2026-06-03 00:00 |
12:32:31.58 |
+42:10:05.7 |
HIP 61335 |
21.71 |
| 2026-06-03 12:00 |
12:32:38.20 |
+42:05:35.8 |
HIP 61335 |
23.89 |
| 2026-06-04 00:00 |
12:32:45.03 |
+42:01:05.1 |
HIP 61335 |
26.70 |
| 2026-06-04 12:00 |
12:32:52.06 |
+41:56:33.5 |
HIP 61386 |
23.78 |
| 2026-06-05 00:00 |
12:32:59.28 |
+41:52:01.0 |
HIP 61386 |
20.78 |
| 2026-06-05 12:00 |
12:33:06.70 |
+41:47:27.7 |
HIP 61367 |
17.36 |
| 2026-06-06 00:00 |
12:33:14.32 |
+41:42:53.5 |
HIP 61367 |
14.61 |
| 2026-06-06 12:00 |
12:33:22.14 |
+41:38:18.6 |
HIP 61367 |
13.06 |
| 2026-06-07 00:00 |
12:33:30.15 |
+41:33:42.8 |
HIP 61317 |
12.62 |
| 2026-06-07 12:00 |
12:33:38.35 |
+41:29:06.3 |
HIP 61317 |
7.80 |
| 2026-06-08 00:00 |
12:33:46.74 |
+41:24:29.0 |
HIP 61317 |
3.09 |
| 2026-06-08 12:00 |
12:33:55.33 |
+41:19:51.0 |
HIP 61317 |
2.47 |
| 2026-06-09 00:00 |
12:34:04.11 |
+41:15:12.2 |
HIP 61317 |
7.16 |
| 2026-06-09 12:00 |
12:34:13.08 |
+41:10:32.7 |
HIP 61317 |
12.07 |
| 2026-06-10 00:00 |
12:34:22.23 |
+41:05:52.5 |
HIP 61317 |
17.03 |
| 2026-06-10 12:00 |
12:34:31.58 |
+41:01:11.7 |
HIP 61277 |
21.38 |
| 2026-06-11 00:00 |
12:34:41.11 |
+40:56:30.1 |
HIP 61277 |
19.03 |
| 2026-06-11 12:00 |
12:34:50.83 |
+40:51:48.0 |
HIP 61277 |
17.85 |
| 2026-06-12 00:00 |
12:35:00.73 |
+40:47:05.1 |
HIP 61370 |
15.48 |
| 2026-06-12 12:00 |
12:35:10.82 |
+40:42:21.7 |
HIP 61370 |
12.04 |
| 2026-06-13 00:00 |
12:35:21.09 |
+40:37:37.6 |
HIP 61514 |
10.04 |
| 2026-06-13 12:00 |
12:35:31.54 |
+40:32:53.0 |
HIP 61514 |
8.09 |
| 2026-06-14 00:00 |
12:35:42.17 |
+40:28:07.7 |
HIP 61514 |
9.10 |
| 2026-06-14 12:00 |
12:35:52.99 |
+40:23:21.9 |
HIP 61514 |
12.38 |
| 2026-06-15 00:00 |
12:36:03.98 |
+40:18:35.6 |
HIP 61514 |
16.67 |
| 2026-06-15 12:00 |
12:36:15.15 |
+40:13:48.7 |
HIP 61514 |
21.38 |
| 2026-06-16 00:00 |
12:36:26.50 |
+40:09:01.4 |
HIP 61644 |
23.24 |
| 2026-06-16 12:00 |
12:36:38.02 |
+40:04:13.5 |
HIP 61644 |
19.38 |
| 2026-06-17 00:00 |
12:36:49.72 |
+39:59:25.2 |
HIP 61644 |
16.29 |
| 2026-06-17 12:00 |
12:37:01.59 |
+39:54:36.3 |
HIP 61644 |
14.51 |
| 2026-06-18 00:00 |
12:37:13.64 |
+39:49:47.1 |
HIP 61644 |
14.54 |
| 2026-06-18 12:00 |
12:37:25.85 |
+39:44:57.4 |
HIP 61644 |
16.41 |
| 2026-06-19 00:00 |
12:37:38.24 |
+39:40:07.3 |
HIP 61644 |
19.60 |
| 2026-06-19 12:00 |
12:37:50.79 |
+39:35:16.8 |
HIP 61609 |
15.22 |
| 2026-06-20 00:00 |
12:38:03.51 |
+39:30:25.9 |
HIP 61609 |
11.62 |
| 2026-06-20 12:00 |
12:38:16.39 |
+39:25:34.7 |
HIP 61696 |
9.27 |
| 2026-06-21 00:00 |
12:38:29.44 |
+39:20:43.1 |
HIP 61696 |
4.14 |
| 2026-06-21 12:00 |
12:38:42.66 |
+39:15:51.2 |
HIP 61696 |
2.87 |
| 2026-06-22 00:00 |
12:38:56.03 |
+39:10:58.9 |
HIP 61696 |
7.74 |