| Parameter |
Value |
| Designation |
C/2026 H1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2026-06-13T12:55:51.447360Z |
| Orbit solution date (soln_date, UTC) |
2026-04-27T13:42:29Z |
| Obs used |
37 |
| NEO |
- |
| M1 |
8.800 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2026-04-19T08:19:12.806400Z |
| Discovery magnitude (MPC) |
20.58 w |
| Discovery observatory (MPC) |
F52 · Pan-STARRS 2, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2026-04-05.0000000 |
| e |
1.00087100 |
| q (au) |
6.083853 |
| a (au) |
-6984.920077 |
| i (deg) |
115.594969 |
| Ω (om, deg) |
178.727430 |
| ω (w, deg) |
349.655446 |
| M (ma, deg) |
-0.000117 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.678 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.678 |
| n |
6.000 |
| gf |
0.919 |
| gb |
-0.714 |
| k |
0.915 |
| δ90 |
5.565 |
| 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 |
11:26:11.36 |
-11:00:44.1 |
HIP 55687 |
25.00 |
| 2026-05-12 12:00 |
11:26:01.06 |
-10:55:25.9 |
HIP 55687 |
21.09 |
| 2026-05-13 00:00 |
11:25:50.94 |
-10:50:09.0 |
HIP 55687 |
18.31 |
| 2026-05-13 12:00 |
11:25:40.99 |
-10:44:53.5 |
HIP 55687 |
17.16 |
| 2026-05-14 00:00 |
11:25:31.23 |
-10:39:39.3 |
HIP 55687 |
17.94 |
| 2026-05-14 12:00 |
11:25:21.65 |
-10:34:26.5 |
HIP 55653 |
19.31 |
| 2026-05-15 00:00 |
11:25:12.24 |
-10:29:15.0 |
HIP 55653 |
19.64 |
| 2026-05-15 12:00 |
11:25:03.02 |
-10:24:05.0 |
HIP 55653 |
21.52 |
| 2026-05-16 00:00 |
11:24:53.97 |
-10:18:56.4 |
HIP 55653 |
24.58 |
| 2026-05-16 12:00 |
11:24:45.11 |
-10:13:49.2 |
HIP 55653 |
28.42 |
| 2026-05-17 00:00 |
11:24:36.43 |
-10:08:43.5 |
HIP 55815 |
29.40 |
| 2026-05-17 12:00 |
11:24:27.93 |
-10:03:39.2 |
HIP 55815 |
28.94 |
| 2026-05-18 00:00 |
11:24:19.60 |
-09:58:36.3 |
HIP 55815 |
29.47 |
| 2026-05-18 12:00 |
11:24:11.46 |
-09:53:35.0 |
HIP 55815 |
30.93 |
| 2026-05-19 00:00 |
11:24:03.50 |
-09:48:35.1 |
HIP 55815 |
33.16 |
| 2026-05-19 12:00 |
11:23:55.71 |
-09:43:36.7 |
HIP 55606 |
28.91 |
| 2026-05-20 00:00 |
11:23:48.11 |
-09:38:39.8 |
HIP 55606 |
23.69 |
| 2026-05-20 12:00 |
11:23:40.68 |
-09:33:44.5 |
HIP 55606 |
18.54 |
| 2026-05-21 00:00 |
11:23:33.44 |
-09:28:50.6 |
HIP 55606 |
13.50 |
| 2026-05-21 12:00 |
11:23:26.37 |
-09:23:58.3 |
HIP 55606 |
8.70 |
| 2026-05-22 00:00 |
11:23:19.48 |
-09:19:07.5 |
HIP 55606 |
4.73 |
| 2026-05-22 12:00 |
11:23:12.76 |
-09:14:18.3 |
HIP 55606 |
4.62 |
| 2026-05-23 00:00 |
11:23:06.23 |
-09:09:30.6 |
HIP 55606 |
8.46 |
| 2026-05-23 12:00 |
11:22:59.87 |
-09:04:44.5 |
HIP 55606 |
13.10 |
| 2026-05-24 00:00 |
11:22:53.68 |
-09:00:00.0 |
HIP 55531 |
11.27 |
| 2026-05-24 12:00 |
11:22:47.67 |
-08:55:16.9 |
HIP 55531 |
6.65 |
| 2026-05-25 00:00 |
11:22:41.84 |
-08:50:35.5 |
HIP 55531 |
3.23 |
| 2026-05-25 12:00 |
11:22:36.18 |
-08:45:55.6 |
HIP 55531 |
4.98 |
| 2026-05-26 00:00 |
11:22:30.70 |
-08:41:17.4 |
HIP 55531 |
9.28 |
| 2026-05-26 12:00 |
11:22:25.39 |
-08:36:40.7 |
HIP 55531 |
13.91 |
| 2026-05-27 00:00 |
11:22:20.25 |
-08:32:05.6 |
HIP 55531 |
18.58 |
| 2026-05-27 12:00 |
11:22:15.28 |
-08:27:32.1 |
HIP 55556 |
23.10 |
| 2026-05-28 00:00 |
11:22:10.49 |
-08:23:00.2 |
HIP 55536 |
19.27 |
| 2026-05-28 12:00 |
11:22:05.86 |
-08:18:29.9 |
HIP 55536 |
15.42 |
| 2026-05-29 00:00 |
11:22:01.41 |
-08:14:01.3 |
HIP 55536 |
12.13 |
| 2026-05-29 12:00 |
11:21:57.13 |
-08:09:34.2 |
HIP 55536 |
9.95 |
| 2026-05-30 00:00 |
11:21:53.02 |
-08:05:08.7 |
HIP 55536 |
9.57 |
| 2026-05-30 12:00 |
11:21:49.07 |
-08:00:44.9 |
HIP 55536 |
11.16 |
| 2026-05-31 00:00 |
11:21:45.30 |
-07:56:22.6 |
HIP 55536 |
14.03 |
| 2026-05-31 12:00 |
11:21:41.69 |
-07:52:02.0 |
HIP 55536 |
17.52 |
| 2026-06-01 00:00 |
11:21:38.25 |
-07:47:43.0 |
HIP 55536 |
21.33 |
| 2026-06-01 12:00 |
11:21:34.98 |
-07:43:25.6 |
HIP 55536 |
25.28 |
| 2026-06-02 00:00 |
11:21:31.87 |
-07:39:09.8 |
HIP 55536 |
29.30 |