| Parameter |
Value |
| Designation |
151P/Helin |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-10-06T14:58:48.158400Z |
| Orbit solution date (soln_date, UTC) |
2022-05-19T21:13:49Z |
| Obs used |
420 |
| NEO |
- |
| M1 |
8.500 |
| K1 |
21.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2010-02-22.0000000 |
| e |
0.57089385 |
| q (au) |
2.491926 |
| a (au) |
5.807247 |
| i (deg) |
4.734715 |
| Ω (om, deg) |
143.554023 |
| ω (w, deg) |
215.530383 |
| M (ma, deg) |
215.436711 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.870 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.870 |
| n |
6.000 |
| gf |
0.929 |
| gb |
-0.828 |
| k |
0.997 |
| δ90 |
1.000 |
| 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 |
14:05:37.78 |
-07:16:34.1 |
HIP 68806 |
6.25 |
| 2026-06-01 12:00 |
14:05:28.29 |
-07:15:56.2 |
HIP 68806 |
3.95 |
| 2026-06-02 00:00 |
14:05:18.91 |
-07:15:19.0 |
HIP 68806 |
2.02 |
| 2026-06-02 12:00 |
14:05:09.63 |
-07:14:42.4 |
HIP 68806 |
2.02 |
| 2026-06-03 00:00 |
14:05:00.45 |
-07:14:06.6 |
HIP 68806 |
3.90 |
| 2026-06-03 12:00 |
14:04:51.37 |
-07:13:31.4 |
HIP 68806 |
6.09 |
| 2026-06-04 00:00 |
14:04:42.39 |
-07:12:56.9 |
HIP 68806 |
8.32 |
| 2026-06-04 12:00 |
14:04:33.53 |
-07:12:23.2 |
HIP 68806 |
10.56 |
| 2026-06-05 00:00 |
14:04:24.76 |
-07:11:50.1 |
HIP 68721 |
10.11 |
| 2026-06-05 12:00 |
14:04:16.11 |
-07:11:17.8 |
HIP 68721 |
9.76 |
| 2026-06-06 00:00 |
14:04:07.56 |
-07:10:46.2 |
HIP 68721 |
9.90 |
| 2026-06-06 12:00 |
14:03:59.12 |
-07:10:15.3 |
HIP 68721 |
10.49 |
| 2026-06-07 00:00 |
14:03:50.79 |
-07:09:45.1 |
HIP 68661 |
8.65 |
| 2026-06-07 12:00 |
14:03:42.58 |
-07:09:15.6 |
HIP 68661 |
6.56 |
| 2026-06-08 00:00 |
14:03:34.47 |
-07:08:46.9 |
HIP 68661 |
4.51 |
| 2026-06-08 12:00 |
14:03:26.47 |
-07:08:18.9 |
HIP 68661 |
2.51 |
| 2026-06-09 00:00 |
14:03:18.59 |
-07:07:51.7 |
HIP 68661 |
0.76 |
| 2026-06-09 12:00 |
14:03:10.83 |
-07:07:25.2 |
HIP 68661 |
1.68 |
| 2026-06-10 00:00 |
14:03:03.17 |
-07:06:59.4 |
HIP 68661 |
3.56 |
| 2026-06-10 12:00 |
14:02:55.64 |
-07:06:34.4 |
HIP 68661 |
5.45 |
| 2026-06-11 00:00 |
14:02:48.22 |
-07:06:10.1 |
HIP 68661 |
7.33 |
| 2026-06-11 12:00 |
14:02:40.92 |
-07:05:46.6 |
HIP 68661 |
9.17 |
| 2026-06-12 00:00 |
14:02:33.73 |
-07:05:23.9 |
HIP 68661 |
10.99 |
| 2026-06-12 12:00 |
14:02:26.67 |
-07:05:01.9 |
HIP 68661 |
12.78 |
| 2026-06-13 00:00 |
14:02:19.72 |
-07:04:40.6 |
HIP 68661 |
14.53 |
| 2026-06-13 12:00 |
14:02:12.90 |
-07:04:20.2 |
HIP 68661 |
16.26 |
| 2026-06-14 00:00 |
14:02:06.20 |
-07:04:00.5 |
HIP 68471 |
15.28 |
| 2026-06-14 12:00 |
14:01:59.62 |
-07:03:41.5 |
HIP 68471 |
13.75 |
| 2026-06-15 00:00 |
14:01:53.16 |
-07:03:23.4 |
HIP 68471 |
12.29 |
| 2026-06-15 12:00 |
14:01:46.83 |
-07:03:06.0 |
HIP 68471 |
10.89 |
| 2026-06-16 00:00 |
14:01:40.62 |
-07:02:49.4 |
HIP 68471 |
9.58 |
| 2026-06-16 12:00 |
14:01:34.53 |
-07:02:33.6 |
HIP 68471 |
8.37 |
| 2026-06-17 00:00 |
14:01:28.58 |
-07:02:18.6 |
HIP 68471 |
7.31 |
| 2026-06-17 12:00 |
14:01:22.74 |
-07:02:04.3 |
HIP 68471 |
6.43 |
| 2026-06-18 00:00 |
14:01:17.04 |
-07:01:50.8 |
HIP 68471 |
5.80 |
| 2026-06-18 12:00 |
14:01:11.46 |
-07:01:38.1 |
HIP 68471 |
5.48 |
| 2026-06-19 00:00 |
14:01:06.01 |
-07:01:26.2 |
HIP 68471 |
5.49 |
| 2026-06-19 12:00 |
14:01:00.69 |
-07:01:15.1 |
HIP 68471 |
5.81 |
| 2026-06-20 00:00 |
14:00:55.49 |
-07:01:04.7 |
HIP 68471 |
6.37 |
| 2026-06-20 12:00 |
14:00:50.42 |
-07:00:55.1 |
HIP 68471 |
7.10 |
| 2026-06-21 00:00 |
14:00:45.49 |
-07:00:46.4 |
HIP 68471 |
7.94 |
| 2026-06-21 12:00 |
14:00:40.68 |
-07:00:38.4 |
HIP 68471 |
8.84 |
| 2026-06-22 00:00 |
14:00:36.00 |
-07:00:31.1 |
HIP 68471 |
9.77 |