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) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 03:23:57.25 | +13:16:19.0 | HIP 15841 | 13.10 |
| 2026-02-03 12:00 | 03:24:00.68 | +13:17:17.1 | HIP 15841 | 14.00 |
| 2026-02-04 00:00 | 03:24:04.28 | +13:18:15.9 | HIP 15841 | 14.96 |
| 2026-02-04 12:00 | 03:24:08.05 | +13:19:15.1 | HIP 15841 | 15.99 |
| 2026-02-05 00:00 | 03:24:12.00 | +13:20:14.9 | HIP 15841 | 17.07 |
| 2026-02-05 12:00 | 03:24:16.12 | +13:21:15.3 | HIP 15841 | 18.21 |
| 2026-02-06 00:00 | 03:24:20.41 | +13:22:16.1 | HIP 15841 | 19.40 |
| 2026-02-06 12:00 | 03:24:24.87 | +13:23:17.5 | HIP 15841 | 20.65 |
| 2026-02-07 00:00 | 03:24:29.50 | +13:24:19.5 | HIP 15975 | 21.84 |
| 2026-02-07 12:00 | 03:24:34.30 | +13:25:21.9 | HIP 15975 | 20.29 |
| 2026-02-08 00:00 | 03:24:39.27 | +13:26:24.9 | HIP 15975 | 18.69 |
| 2026-02-08 12:00 | 03:24:44.40 | +13:27:28.4 | HIP 15975 | 17.06 |
| 2026-02-09 00:00 | 03:24:49.71 | +13:28:32.3 | HIP 15975 | 15.39 |
| 2026-02-09 12:00 | 03:24:55.18 | +13:29:36.8 | HIP 15975 | 13.69 |
| 2026-02-10 00:00 | 03:25:00.82 | +13:30:41.8 | HIP 15975 | 11.95 |
| 2026-02-10 12:00 | 03:25:06.62 | +13:31:47.2 | HIP 15975 | 10.17 |
| 2026-02-11 00:00 | 03:25:12.59 | +13:32:53.2 | HIP 15975 | 8.36 |
| 2026-02-11 12:00 | 03:25:18.73 | +13:33:59.6 | HIP 15975 | 6.51 |
| 2026-02-12 00:00 | 03:25:25.03 | +13:35:06.5 | HIP 15975 | 4.63 |
| 2026-02-12 12:00 | 03:25:31.49 | +13:36:13.9 | HIP 15975 | 2.73 |
| 2026-02-13 00:00 | 03:25:38.11 | +13:37:21.8 | HIP 15975 | 0.91 |
| 2026-02-13 12:00 | 03:25:44.90 | +13:38:30.1 | HIP 15975 | 1.43 |
| 2026-02-14 00:00 | 03:25:51.85 | +13:39:38.9 | HIP 15975 | 3.39 |
| 2026-02-14 12:00 | 03:25:58.97 | +13:40:48.1 | HIP 15975 | 5.45 |
| 2026-02-15 00:00 | 03:26:06.24 | +13:41:57.8 | HIP 15975 | 7.55 |
| 2026-02-15 12:00 | 03:26:13.67 | +13:43:07.9 | HIP 15975 | 9.69 |
| 2026-02-16 00:00 | 03:26:21.26 | +13:44:18.4 | HIP 15975 | 11.88 |
| 2026-02-16 12:00 | 03:26:29.01 | +13:45:29.4 | HIP 15975 | 14.09 |
| 2026-02-17 00:00 | 03:26:36.92 | +13:46:40.8 | HIP 15975 | 16.35 |
| 2026-02-17 12:00 | 03:26:44.99 | +13:47:52.7 | HIP 15975 | 18.64 |
| 2026-02-18 00:00 | 03:26:53.21 | +13:49:04.9 | HIP 15975 | 20.97 |
| 2026-02-18 12:00 | 03:27:01.59 | +13:50:17.6 | HIP 15975 | 23.33 |
| 2026-02-19 00:00 | 03:27:10.12 | +13:51:30.7 | HIP 15975 | 25.73 |
| 2026-02-19 12:00 | 03:27:18.81 | +13:52:44.1 | HIP 15975 | 28.16 |
| 2026-02-20 00:00 | 03:27:27.65 | +13:53:58.0 | HIP 16007 | 30.25 |
| 2026-02-20 12:00 | 03:27:36.64 | +13:55:12.2 | HIP 16007 | 30.77 |
| 2026-02-21 00:00 | 03:27:45.78 | +13:56:26.9 | HIP 16007 | 31.50 |
| 2026-02-21 12:00 | 03:27:55.08 | +13:57:41.9 | HIP 16007 | 32.44 |
| 2026-02-22 00:00 | 03:28:04.52 | +13:58:57.2 | HIP 16007 | 33.58 |
| 2026-02-22 12:00 | 03:28:14.12 | +14:00:13.0 | HIP 16304 | 32.16 |
| 2026-02-23 00:00 | 03:28:23.86 | +14:01:29.1 | HIP 16304 | 29.48 |
| 2026-02-23 12:00 | 03:28:33.75 | +14:02:45.5 | HIP 16304 | 26.76 |
| 2026-02-24 00:00 | 03:28:43.79 | +14:04:02.3 | HIP 16304 | 24.01 |