151P/Helin
| 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 |
0.945 |
| 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) |
| 2026-02-03 00:00 |
14:36:47.09 |
-10:35:26.0 |
HIP 71632 |
32.84 |
| 2026-02-03 12:00 |
14:36:51.03 |
-10:35:23.3 |
HIP 71632 |
31.87 |
| 2026-02-04 00:00 |
14:36:54.85 |
-10:35:20.0 |
HIP 71632 |
30.93 |
| 2026-02-04 12:00 |
14:36:58.54 |
-10:35:16.0 |
HIP 71632 |
30.02 |
| 2026-02-05 00:00 |
14:37:02.10 |
-10:35:11.3 |
HIP 71632 |
29.14 |
| 2026-02-05 12:00 |
14:37:05.53 |
-10:35:06.0 |
HIP 71632 |
28.29 |
| 2026-02-06 00:00 |
14:37:08.83 |
-10:35:00.1 |
HIP 71632 |
27.48 |
| 2026-02-06 12:00 |
14:37:12.00 |
-10:34:53.4 |
HIP 71632 |
26.69 |
| 2026-02-07 00:00 |
14:37:15.04 |
-10:34:46.1 |
HIP 71632 |
25.94 |
| 2026-02-07 12:00 |
14:37:17.96 |
-10:34:38.2 |
HIP 71632 |
25.22 |
| 2026-02-08 00:00 |
14:37:20.73 |
-10:34:29.5 |
HIP 71632 |
24.53 |
| 2026-02-08 12:00 |
14:37:23.38 |
-10:34:20.3 |
HIP 71632 |
23.87 |
| 2026-02-09 00:00 |
14:37:25.90 |
-10:34:10.3 |
HIP 71632 |
23.25 |
| 2026-02-09 12:00 |
14:37:28.28 |
-10:33:59.7 |
HIP 71632 |
22.65 |
| 2026-02-10 00:00 |
14:37:30.53 |
-10:33:48.4 |
HIP 71632 |
22.10 |
| 2026-02-10 12:00 |
14:37:32.65 |
-10:33:36.5 |
HIP 71632 |
21.57 |
| 2026-02-11 00:00 |
14:37:34.63 |
-10:33:23.8 |
HIP 71632 |
21.08 |
| 2026-02-11 12:00 |
14:37:36.48 |
-10:33:10.6 |
HIP 71632 |
20.63 |
| 2026-02-12 00:00 |
14:37:38.20 |
-10:32:56.6 |
HIP 71632 |
20.21 |
| 2026-02-12 12:00 |
14:37:39.78 |
-10:32:42.0 |
HIP 71632 |
19.83 |
| 2026-02-13 00:00 |
14:37:41.22 |
-10:32:26.7 |
HIP 71632 |
19.48 |
| 2026-02-13 12:00 |
14:37:42.53 |
-10:32:10.8 |
HIP 71632 |
19.17 |
| 2026-02-14 00:00 |
14:37:43.71 |
-10:31:54.2 |
HIP 71632 |
18.90 |
| 2026-02-14 12:00 |
14:37:44.74 |
-10:31:36.9 |
HIP 71632 |
18.67 |
| 2026-02-15 00:00 |
14:37:45.65 |
-10:31:19.0 |
HIP 71632 |
18.48 |
| 2026-02-15 12:00 |
14:37:46.41 |
-10:31:00.4 |
HIP 71632 |
18.33 |
| 2026-02-16 00:00 |
14:37:47.04 |
-10:30:41.1 |
HIP 71632 |
18.22 |
| 2026-02-16 12:00 |
14:37:47.53 |
-10:30:21.2 |
HIP 71632 |
18.15 |
| 2026-02-17 00:00 |
14:37:47.88 |
-10:30:00.6 |
HIP 71632 |
18.13 |
| 2026-02-17 12:00 |
14:37:48.10 |
-10:29:39.4 |
HIP 71632 |
18.14 |
| 2026-02-18 00:00 |
14:37:48.18 |
-10:29:17.5 |
HIP 71632 |
18.20 |
| 2026-02-18 12:00 |
14:37:48.12 |
-10:28:54.9 |
HIP 71632 |
18.30 |
| 2026-02-19 00:00 |
14:37:47.92 |
-10:28:31.7 |
HIP 71632 |
18.44 |
| 2026-02-19 12:00 |
14:37:47.59 |
-10:28:07.9 |
HIP 71632 |
18.63 |
| 2026-02-20 00:00 |
14:37:47.11 |
-10:27:43.3 |
HIP 71632 |
18.86 |
| 2026-02-20 12:00 |
14:37:46.50 |
-10:27:18.2 |
HIP 71632 |
19.13 |
| 2026-02-21 00:00 |
14:37:45.76 |
-10:26:52.4 |
HIP 71632 |
19.44 |
| 2026-02-21 12:00 |
14:37:44.87 |
-10:26:25.9 |
HIP 71632 |
19.80 |
| 2026-02-22 00:00 |
14:37:43.85 |
-10:25:58.8 |
HIP 71632 |
20.19 |
| 2026-02-22 12:00 |
14:37:42.68 |
-10:25:31.1 |
HIP 71632 |
20.63 |
| 2026-02-23 00:00 |
14:37:41.38 |
-10:25:02.7 |
HIP 71632 |
21.10 |
| 2026-02-23 12:00 |
14:37:39.95 |
-10:24:33.7 |
HIP 71632 |
21.62 |
| 2026-02-24 00:00 |
14:37:38.37 |
-10:24:04.1 |
HIP 71632 |
22.18 |