| Parameter |
Value |
| Designation |
C/2025 E1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2026-09-23T17:02:20.708160Z |
| Orbit solution date (soln_date, UTC) |
2026-05-28T12:12:15Z |
| Obs used |
257 |
| NEO |
- |
| M1 |
6.800 |
| K1 |
13.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-03-02T10:18:16.963200Z |
| Discovery magnitude (MPC) |
20.69 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2026-02-03.0000000 |
| e |
0.99752528 |
| q (au) |
3.998116 |
| a (au) |
1615.584557 |
| i (deg) |
69.060482 |
| Ω (om, deg) |
344.592127 |
| ω (w, deg) |
274.421653 |
| M (ma, deg) |
359.996468 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.788 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.788 |
| n |
6.000 |
| gf |
0.973 |
| gb |
-0.703 |
| k |
0.800 |
| δ90 |
9.966 |
| 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) |
| 2026-06-01 00:00 |
08:33:13.80 |
-63:24:06.4 |
HIP 42002 |
5.86 |
| 2026-06-01 12:00 |
08:33:21.75 |
-63:22:13.2 |
HIP 42002 |
3.78 |
| 2026-06-02 00:00 |
08:33:30.11 |
-63:20:22.3 |
HIP 42002 |
1.72 |
| 2026-06-02 12:00 |
08:33:38.90 |
-63:18:33.7 |
HIP 42002 |
0.39 |
| 2026-06-03 00:00 |
08:33:48.10 |
-63:16:47.4 |
HIP 42002 |
2.40 |
| 2026-06-03 12:00 |
08:33:57.71 |
-63:15:03.4 |
HIP 42002 |
4.44 |
| 2026-06-04 00:00 |
08:34:07.74 |
-63:13:21.7 |
HIP 42002 |
6.47 |
| 2026-06-04 12:00 |
08:34:18.17 |
-63:11:42.4 |
HIP 42002 |
8.50 |
| 2026-06-05 00:00 |
08:34:29.01 |
-63:10:05.4 |
HIP 42002 |
10.51 |
| 2026-06-05 12:00 |
08:34:40.24 |
-63:08:30.7 |
HIP 42002 |
12.53 |
| 2026-06-06 00:00 |
08:34:51.87 |
-63:06:58.5 |
HIP 42002 |
14.54 |
| 2026-06-06 12:00 |
08:35:03.89 |
-63:05:28.7 |
HIP 42002 |
16.54 |
| 2026-06-07 00:00 |
08:35:16.31 |
-63:04:01.3 |
HIP 42002 |
18.55 |
| 2026-06-07 12:00 |
08:35:29.11 |
-63:02:36.3 |
HIP 42286 |
16.90 |
| 2026-06-08 00:00 |
08:35:42.29 |
-63:01:13.8 |
HIP 42286 |
14.87 |
| 2026-06-08 12:00 |
08:35:55.86 |
-62:59:53.7 |
HIP 42286 |
12.83 |
| 2026-06-09 00:00 |
08:36:09.80 |
-62:58:36.1 |
HIP 42286 |
10.79 |
| 2026-06-09 12:00 |
08:36:24.12 |
-62:57:21.0 |
HIP 42286 |
8.75 |
| 2026-06-10 00:00 |
08:36:38.80 |
-62:56:08.4 |
HIP 42286 |
6.72 |
| 2026-06-10 12:00 |
08:36:53.86 |
-62:54:58.4 |
HIP 42286 |
4.72 |
| 2026-06-11 00:00 |
08:37:09.29 |
-62:53:50.9 |
HIP 42286 |
2.86 |
| 2026-06-11 12:00 |
08:37:25.08 |
-62:52:45.9 |
HIP 42286 |
1.71 |
| 2026-06-12 00:00 |
08:37:41.22 |
-62:51:43.5 |
HIP 42286 |
2.60 |
| 2026-06-12 12:00 |
08:37:57.73 |
-62:50:43.7 |
HIP 42381 |
3.44 |
| 2026-06-13 00:00 |
08:38:14.59 |
-62:49:46.5 |
HIP 42381 |
1.72 |
| 2026-06-13 12:00 |
08:38:31.80 |
-62:48:51.8 |
HIP 42381 |
1.79 |
| 2026-06-14 00:00 |
08:38:49.37 |
-62:47:59.8 |
HIP 42381 |
3.58 |
| 2026-06-14 12:00 |
08:39:07.27 |
-62:47:10.5 |
HIP 42381 |
5.65 |
| 2026-06-15 00:00 |
08:39:25.53 |
-62:46:23.8 |
HIP 42381 |
7.81 |
| 2026-06-15 12:00 |
08:39:44.12 |
-62:45:39.7 |
HIP 42381 |
10.01 |
| 2026-06-16 00:00 |
08:40:03.05 |
-62:44:58.3 |
HIP 42381 |
12.25 |
| 2026-06-16 12:00 |
08:40:22.31 |
-62:44:19.6 |
HIP 42490 |
13.41 |
| 2026-06-17 00:00 |
08:40:41.91 |
-62:43:43.6 |
HIP 42490 |
13.78 |
| 2026-06-17 12:00 |
08:41:01.83 |
-62:43:10.3 |
HIP 42490 |
14.57 |
| 2026-06-18 00:00 |
08:41:22.08 |
-62:42:39.7 |
HIP 42490 |
15.75 |
| 2026-06-18 12:00 |
08:41:42.65 |
-62:42:11.8 |
HIP 42490 |
17.23 |
| 2026-06-19 00:00 |
08:42:03.54 |
-62:41:46.6 |
HIP 42490 |
18.96 |
| 2026-06-19 12:00 |
08:42:24.76 |
-62:41:24.2 |
HIP 42889 |
17.07 |
| 2026-06-20 00:00 |
08:42:46.28 |
-62:41:04.4 |
HIP 42889 |
14.91 |
| 2026-06-20 12:00 |
08:43:08.12 |
-62:40:47.5 |
HIP 42889 |
12.88 |
| 2026-06-21 00:00 |
08:43:30.27 |
-62:40:33.2 |
HIP 42889 |
11.07 |
| 2026-06-21 12:00 |
08:43:52.73 |
-62:40:21.7 |
HIP 42889 |
9.64 |
| 2026-06-22 00:00 |
08:44:15.49 |
-62:40:13.0 |
HIP 42889 |
8.81 |