| Parameter |
Value |
| Designation |
C/2023 H3 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2024-02-18T22:29:26.165760Z |
| Orbit solution date (soln_date, UTC) |
2026-04-27T13:42:19Z |
| Obs used |
82 |
| NEO |
- |
| M1 |
14.000 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2023-04-28T09:29:59.020800Z |
| Discovery magnitude (MPC) |
20.89 w |
| Discovery observatory (MPC) |
F52 · Pan-STARRS 2, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-12-27.0000000 |
| e |
0.61615996 |
| q (au) |
5.232462 |
| a (au) |
13.631882 |
| i (deg) |
2.489026 |
| Ω (om, deg) |
55.102514 |
| ω (w, deg) |
193.320297 |
| M (ma, deg) |
358.943771 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.936 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.936 |
| n |
2.000 |
| gf |
0.998 |
| gb |
-0.935 |
| k |
1.000 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
21:57:06.86 |
-15:06:32.0 |
HIP 108414 |
9.83 |
| 2026-05-12 12:00 |
21:57:15.12 |
-15:05:59.8 |
HIP 108414 |
7.93 |
| 2026-05-13 00:00 |
21:57:23.25 |
-15:05:28.3 |
HIP 108414 |
6.15 |
| 2026-05-13 12:00 |
21:57:31.26 |
-15:04:57.5 |
HIP 108414 |
4.60 |
| 2026-05-14 00:00 |
21:57:39.15 |
-15:04:27.3 |
HIP 108414 |
3.56 |
| 2026-05-14 12:00 |
21:57:46.91 |
-15:03:57.8 |
HIP 108414 |
3.44 |
| 2026-05-15 00:00 |
21:57:54.54 |
-15:03:29.0 |
HIP 108414 |
4.27 |
| 2026-05-15 12:00 |
21:58:02.05 |
-15:03:00.8 |
HIP 108452 |
3.41 |
| 2026-05-16 00:00 |
21:58:09.43 |
-15:02:33.4 |
HIP 108452 |
2.96 |
| 2026-05-16 12:00 |
21:58:16.68 |
-15:02:06.6 |
HIP 108452 |
3.54 |
| 2026-05-17 00:00 |
21:58:23.80 |
-15:01:40.5 |
HIP 108452 |
4.75 |
| 2026-05-17 12:00 |
21:58:30.80 |
-15:01:15.1 |
HIP 108452 |
6.21 |
| 2026-05-18 00:00 |
21:58:37.67 |
-15:00:50.3 |
HIP 108452 |
7.75 |
| 2026-05-18 12:00 |
21:58:44.41 |
-15:00:26.3 |
HIP 108452 |
9.32 |
| 2026-05-19 00:00 |
21:58:51.02 |
-15:00:03.0 |
HIP 108522 |
9.44 |
| 2026-05-19 12:00 |
21:58:57.50 |
-14:59:40.3 |
HIP 108522 |
9.26 |
| 2026-05-20 00:00 |
21:59:03.85 |
-14:59:18.3 |
HIP 108522 |
9.35 |
| 2026-05-20 12:00 |
21:59:10.08 |
-14:58:57.1 |
HIP 108522 |
9.69 |
| 2026-05-21 00:00 |
21:59:16.17 |
-14:58:36.5 |
HIP 108522 |
10.23 |
| 2026-05-21 12:00 |
21:59:22.13 |
-14:58:16.6 |
HIP 108522 |
10.93 |
| 2026-05-22 00:00 |
21:59:27.96 |
-14:57:57.4 |
HIP 108522 |
11.76 |
| 2026-05-22 12:00 |
21:59:33.67 |
-14:57:38.9 |
HIP 108522 |
12.67 |
| 2026-05-23 00:00 |
21:59:39.24 |
-14:57:21.2 |
HIP 108522 |
13.64 |
| 2026-05-23 12:00 |
21:59:44.68 |
-14:57:04.1 |
HIP 108522 |
14.64 |
| 2026-05-24 00:00 |
21:59:49.99 |
-14:56:47.7 |
HIP 108522 |
15.67 |
| 2026-05-24 12:00 |
21:59:55.17 |
-14:56:32.0 |
HIP 108522 |
16.70 |
| 2026-05-25 00:00 |
22:00:00.22 |
-14:56:17.0 |
HIP 108522 |
17.74 |
| 2026-05-25 12:00 |
22:00:05.14 |
-14:56:02.7 |
HIP 108522 |
18.77 |
| 2026-05-26 00:00 |
22:00:09.92 |
-14:55:49.1 |
HIP 108522 |
19.79 |
| 2026-05-26 12:00 |
22:00:14.58 |
-14:55:36.2 |
HIP 108522 |
20.79 |
| 2026-05-27 00:00 |
22:00:19.10 |
-14:55:24.0 |
HIP 108522 |
21.78 |
| 2026-05-27 12:00 |
22:00:23.49 |
-14:55:12.5 |
HIP 108522 |
22.74 |
| 2026-05-28 00:00 |
22:00:27.75 |
-14:55:01.7 |
HIP 108522 |
23.69 |
| 2026-05-28 12:00 |
22:00:31.88 |
-14:54:51.6 |
HIP 108522 |
24.60 |
| 2026-05-29 00:00 |
22:00:35.87 |
-14:54:42.2 |
HIP 108522 |
25.49 |
| 2026-05-29 12:00 |
22:00:39.74 |
-14:54:33.6 |
HIP 108522 |
26.36 |
| 2026-05-30 00:00 |
22:00:43.47 |
-14:54:25.6 |
HIP 108522 |
27.19 |
| 2026-05-30 12:00 |
22:00:47.07 |
-14:54:18.3 |
HIP 108522 |
28.00 |
| 2026-05-31 00:00 |
22:00:50.53 |
-14:54:11.7 |
HIP 108522 |
28.78 |
| 2026-05-31 12:00 |
22:00:53.87 |
-14:54:05.8 |
HIP 108522 |
29.52 |
| 2026-06-01 00:00 |
22:00:57.07 |
-14:54:00.7 |
HIP 108522 |
30.24 |
| 2026-06-01 12:00 |
22:01:00.13 |
-14:53:56.2 |
HIP 108522 |
30.93 |
| 2026-06-02 00:00 |
22:01:03.07 |
-14:53:52.5 |
HIP 108522 |
31.58 |