152P/Helin-Lawrence
Metadata
| Parameter | Value |
|---|---|
| Designation | 152P/Helin-Lawrence |
| Type | P |
| Perihelion (tp_cal, UTC) | 2012-07-08T08:45:15.160320Z |
| Orbit solution date (soln_date, UTC) | 2025-03-06T13:42:28Z |
| Obs used | 1298 |
| NEO | - |
| M1 | 12.700 |
| K1 | 6.000 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2015-02-09.0000000 |
| e | 0.30721897 |
| q (au) | 3.112792 |
| a (au) | 4.493183 |
| i (deg) | 9.868309 |
| Ω (om, deg) | 91.899208 |
| ω (w, deg) | 163.585758 |
| M (ma, deg) | 97.858042 |
Magnitude
Scatter + Global Linear
$$ M_a = (12.595 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 12.595 |
| n | 2.000 |
| gf | 1.000 |
| gb | -0.873 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) | End (UTC) | a | b |
|---|---|---|---|
| 2020-02-20 | 2022-01-12 | +17.5656 | -9.164 |
| 2022-01-12 | 2023-08-23 | -11.7992 | +7.162 |
| 2023-08-23 | 2025-01-04 | +22.4248 | -14.516 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Finding Chart
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 04:15:14.46 | +17:41:44.1 | HIP 19651 | 38.14 |
| 2026-05-12 12:00 | 04:15:37.60 | +17:43:01.2 | HIP 20041 | 37.59 |
| 2026-05-13 00:00 | 04:16:00.77 | +17:44:18.0 | HIP 20041 | 33.71 |
| 2026-05-13 12:00 | 04:16:23.96 | +17:45:34.6 | HIP 20041 | 30.38 |
| 2026-05-14 00:00 | 04:16:47.18 | +17:46:50.9 | HIP 20041 | 27.82 |
| 2026-05-14 12:00 | 04:17:10.43 | +17:48:06.9 | HIP 20041 | 26.25 |
| 2026-05-15 00:00 | 04:17:33.71 | +17:49:22.7 | HIP 20041 | 25.85 |
| 2026-05-15 12:00 | 04:17:57.00 | +17:50:38.2 | HIP 20056 | 24.80 |
| 2026-05-16 00:00 | 04:18:20.33 | +17:51:53.5 | HIP 20146 | 23.34 |
| 2026-05-16 12:00 | 04:18:43.68 | +17:53:08.5 | HIP 20146 | 22.41 |
| 2026-05-17 00:00 | 04:19:07.05 | +17:54:23.2 | HIP 20146 | 22.90 |
| 2026-05-17 12:00 | 04:19:30.44 | +17:55:37.6 | HIP 20146 | 24.73 |
| 2026-05-18 00:00 | 04:19:53.85 | +17:56:51.8 | HIP 20146 | 27.63 |
| 2026-05-18 12:00 | 04:20:17.29 | +17:58:05.7 | HIP 20336 | 23.89 |
| 2026-05-19 00:00 | 04:20:40.74 | +17:59:19.3 | HIP 20336 | 19.57 |
| 2026-05-19 12:00 | 04:21:04.22 | +18:00:32.6 | HIP 20336 | 16.13 |
| 2026-05-20 00:00 | 04:21:27.71 | +18:01:45.6 | HIP 20336 | 14.25 |
| 2026-05-20 12:00 | 04:21:51.22 | +18:02:58.3 | HIP 20336 | 14.53 |
| 2026-05-21 00:00 | 04:22:14.74 | +18:04:10.8 | HIP 20336 | 16.88 |
| 2026-05-21 12:00 | 04:22:38.29 | +18:05:23.0 | HIP 20336 | 20.59 |
| 2026-05-22 00:00 | 04:23:01.84 | +18:06:34.8 | HIP 20563 | 18.95 |
| 2026-05-22 12:00 | 04:23:25.42 | +18:07:46.4 | HIP 20563 | 14.40 |
| 2026-05-23 00:00 | 04:23:49.00 | +18:08:57.7 | HIP 20563 | 11.00 |
| 2026-05-23 12:00 | 04:24:12.60 | +18:10:08.7 | HIP 20563 | 10.02 |
| 2026-05-24 00:00 | 04:24:36.21 | +18:11:19.4 | HIP 20563 | 12.05 |
| 2026-05-24 12:00 | 04:24:59.84 | +18:12:29.8 | HIP 20563 | 16.00 |
| 2026-05-25 00:00 | 04:25:23.47 | +18:13:39.8 | HIP 20679 | 13.85 |
| 2026-05-25 12:00 | 04:25:47.12 | +18:14:49.6 | HIP 20679 | 13.79 |
| 2026-05-26 00:00 | 04:26:10.77 | +18:15:59.1 | HIP 20780 | 13.32 |
| 2026-05-26 12:00 | 04:26:34.44 | +18:17:08.3 | HIP 20780 | 8.61 |
| 2026-05-27 00:00 | 04:26:58.11 | +18:18:17.2 | HIP 20782 | 5.97 |
| 2026-05-27 12:00 | 04:27:21.80 | +18:19:25.8 | HIP 20782 | 7.78 |
| 2026-05-28 00:00 | 04:27:45.49 | +18:20:34.0 | HIP 20782 | 12.29 |
| 2026-05-28 12:00 | 04:28:09.19 | +18:21:42.0 | HIP 20782 | 17.54 |
| 2026-05-29 00:00 | 04:28:32.89 | +18:22:49.7 | HIP 20782 | 23.02 |
| 2026-05-29 12:00 | 04:28:56.60 | +18:23:57.0 | HIP 20990 | 18.93 |
| 2026-05-30 00:00 | 04:29:20.32 | +18:25:04.0 | HIP 20990 | 15.29 |
| 2026-05-30 12:00 | 04:29:44.04 | +18:26:10.8 | HIP 20990 | 13.23 |
| 2026-05-31 00:00 | 04:30:07.76 | +18:27:17.2 | HIP 20990 | 13.49 |
| 2026-05-31 12:00 | 04:30:31.49 | +18:28:23.3 | HIP 20990 | 15.96 |
| 2026-06-01 00:00 | 04:30:55.22 | +18:29:29.0 | HIP 20990 | 19.82 |
| 2026-06-01 12:00 | 04:31:18.96 | +18:30:34.5 | HIP 21089 | 18.75 |
| 2026-06-02 00:00 | 04:31:42.69 | +18:31:39.7 | HIP 21089 | 19.15 |