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) |
|---|---|---|---|---|
| 2026-06-01 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 |
| 2026-06-02 12:00 | 04:32:06.43 | +18:32:44.5 | HIP 21173 | 20.09 |
| 2026-06-03 00:00 | 04:32:30.17 | +18:33:49.0 | HIP 21173 | 20.94 |
| 2026-06-03 12:00 | 04:32:53.91 | +18:34:53.2 | HIP 21173 | 23.22 |
| 2026-06-04 00:00 | 04:33:17.65 | +18:35:57.1 | HIP 21350 | 25.14 |
| 2026-06-04 12:00 | 04:33:41.39 | +18:37:00.6 | HIP 21350 | 20.85 |
| 2026-06-05 00:00 | 04:34:05.12 | +18:38:03.9 | HIP 21350 | 17.41 |
| 2026-06-05 12:00 | 04:34:28.86 | +18:39:06.8 | HIP 21350 | 15.39 |
| 2026-06-06 00:00 | 04:34:52.59 | +18:40:09.3 | HIP 21350 | 15.35 |
| 2026-06-06 12:00 | 04:35:16.32 | +18:41:11.6 | HIP 21350 | 17.32 |
| 2026-06-07 00:00 | 04:35:40.04 | +18:42:13.5 | HIP 21467 | 13.99 |
| 2026-06-07 12:00 | 04:36:03.76 | +18:43:15.1 | HIP 21467 | 8.29 |
| 2026-06-08 00:00 | 04:36:27.48 | +18:44:16.4 | HIP 21467 | 2.62 |
| 2026-06-08 12:00 | 04:36:51.19 | +18:45:17.4 | HIP 21467 | 3.20 |
| 2026-06-09 00:00 | 04:37:14.89 | +18:46:18.0 | HIP 21467 | 8.87 |
| 2026-06-09 12:00 | 04:37:38.58 | +18:47:18.3 | HIP 21621 | 12.85 |
| 2026-06-10 00:00 | 04:38:02.27 | +18:48:18.2 | HIP 21621 | 8.05 |
| 2026-06-10 12:00 | 04:38:25.95 | +18:49:17.8 | HIP 21621 | 5.41 |
| 2026-06-11 00:00 | 04:38:49.62 | +18:50:17.1 | HIP 21621 | 7.65 |
| 2026-06-11 12:00 | 04:39:13.28 | +18:51:16.1 | HIP 21621 | 12.34 |
| 2026-06-12 00:00 | 04:39:36.93 | +18:52:14.7 | HIP 21687 | 15.25 |
| 2026-06-12 12:00 | 04:40:00.57 | +18:53:13.0 | HIP 21687 | 16.53 |
| 2026-06-13 00:00 | 04:40:24.20 | +18:54:10.9 | HIP 21687 | 19.46 |
| 2026-06-13 12:00 | 04:40:47.81 | +18:55:08.5 | HIP 21687 | 23.41 |
| 2026-06-14 00:00 | 04:41:11.41 | +18:56:05.8 | HIP 21932 | 24.63 |
| 2026-06-14 12:00 | 04:41:35.00 | +18:57:02.7 | HIP 21932 | 19.01 |
| 2026-06-15 00:00 | 04:41:58.57 | +18:57:59.3 | HIP 21932 | 13.43 |
| 2026-06-15 12:00 | 04:42:22.12 | +18:58:55.5 | HIP 21932 | 7.96 |
| 2026-06-16 00:00 | 04:42:45.66 | +18:59:51.4 | HIP 21932 | 3.18 |
| 2026-06-16 12:00 | 04:43:09.18 | +19:00:47.0 | HIP 21932 | 4.52 |
| 2026-06-17 00:00 | 04:43:32.68 | +19:01:42.2 | HIP 21932 | 9.71 |
| 2026-06-17 12:00 | 04:43:56.16 | +19:02:37.0 | HIP 21932 | 15.20 |
| 2026-06-18 00:00 | 04:44:19.63 | +19:03:31.6 | HIP 21932 | 20.76 |
| 2026-06-18 12:00 | 04:44:43.07 | +19:04:25.7 | HIP 22112 | 19.54 |
| 2026-06-19 00:00 | 04:45:06.49 | +19:05:19.6 | HIP 22112 | 15.84 |
| 2026-06-19 12:00 | 04:45:29.89 | +19:06:13.0 | HIP 22112 | 13.53 |
| 2026-06-20 00:00 | 04:45:53.27 | +19:07:06.2 | HIP 22185 | 8.62 |
| 2026-06-20 12:00 | 04:46:16.62 | +19:07:59.0 | HIP 22185 | 4.54 |
| 2026-06-21 00:00 | 04:46:39.95 | +19:08:51.4 | HIP 22185 | 5.40 |
| 2026-06-21 12:00 | 04:47:03.25 | +19:09:43.6 | HIP 22185 | 10.00 |
| 2026-06-22 00:00 | 04:47:26.53 | +19:10:35.3 | HIP 22185 | 15.25 |