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) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 03:42:42.29 | +15:28:13.7 | HIP 17318 | 21.08 |
| 2026-03-26 12:00 | 03:42:59.70 | +15:29:42.2 | HIP 17318 | 20.89 |
| 2026-03-27 00:00 | 03:43:17.20 | +15:31:10.8 | HIP 17318 | 21.64 |
| 2026-03-27 12:00 | 03:43:34.80 | +15:32:39.4 | HIP 17318 | 23.26 |
| 2026-03-28 00:00 | 03:43:52.49 | +15:34:08.0 | HIP 17318 | 25.59 |
| 2026-03-28 12:00 | 03:44:10.27 | +15:35:36.7 | HIP 17413 | 26.08 |
| 2026-03-29 00:00 | 03:44:28.15 | +15:37:05.3 | HIP 17413 | 25.73 |
| 2026-03-29 12:00 | 03:44:46.12 | +15:38:34.1 | HIP 17413 | 26.18 |
| 2026-03-30 00:00 | 03:45:04.17 | +15:40:02.8 | HIP 17413 | 27.41 |
| 2026-03-30 12:00 | 03:45:22.32 | +15:41:31.5 | HIP 17413 | 29.33 |
| 2026-03-31 00:00 | 03:45:40.55 | +15:43:00.3 | HIP 17413 | 31.83 |
| 2026-03-31 12:00 | 03:45:58.87 | +15:44:29.0 | HIP 17413 | 34.78 |
| 2026-04-01 00:00 | 03:46:17.28 | +15:45:57.8 | HIP 17610 | 36.49 |
| 2026-04-01 12:00 | 03:46:35.78 | +15:47:26.5 | HIP 17804 | 34.23 |
| 2026-04-02 00:00 | 03:46:54.36 | +15:48:55.3 | HIP 17804 | 31.29 |
| 2026-04-02 12:00 | 03:47:13.02 | +15:50:24.0 | HIP 17804 | 28.82 |
| 2026-04-03 00:00 | 03:47:31.77 | +15:51:52.7 | HIP 17804 | 26.94 |
| 2026-04-03 12:00 | 03:47:50.60 | +15:53:21.4 | HIP 17804 | 25.80 |
| 2026-04-04 00:00 | 03:48:09.52 | +15:54:50.1 | HIP 17804 | 25.51 |
| 2026-04-04 12:00 | 03:48:28.52 | +15:56:18.8 | HIP 17944 | 25.43 |
| 2026-04-05 00:00 | 03:48:47.59 | +15:57:47.4 | HIP 17944 | 20.69 |
| 2026-04-05 12:00 | 03:49:06.75 | +15:59:16.0 | HIP 17944 | 15.99 |
| 2026-04-06 00:00 | 03:49:25.99 | +16:00:44.5 | HIP 17944 | 11.37 |
| 2026-04-06 12:00 | 03:49:45.31 | +16:02:13.1 | HIP 17944 | 7.05 |
| 2026-04-07 00:00 | 03:50:04.71 | +16:03:41.6 | HIP 17944 | 4.20 |
| 2026-04-07 12:00 | 03:50:24.18 | +16:05:10.0 | HIP 17944 | 5.78 |
| 2026-04-08 00:00 | 03:50:43.73 | +16:06:38.4 | HIP 17944 | 9.88 |
| 2026-04-08 12:00 | 03:51:03.36 | +16:08:06.7 | HIP 17944 | 14.52 |
| 2026-04-09 00:00 | 03:51:23.07 | +16:09:35.0 | HIP 17944 | 19.32 |
| 2026-04-09 12:00 | 03:51:42.85 | +16:11:03.2 | HIP 17944 | 24.20 |
| 2026-04-10 00:00 | 03:52:02.70 | +16:12:31.4 | HIP 18227 | 26.42 |
| 2026-04-10 12:00 | 03:52:22.63 | +16:13:59.5 | HIP 18227 | 22.38 |
| 2026-04-11 00:00 | 03:52:42.63 | +16:15:27.5 | HIP 18227 | 18.80 |
| 2026-04-11 12:00 | 03:53:02.70 | +16:16:55.4 | HIP 18227 | 15.99 |
| 2026-04-12 00:00 | 03:53:22.85 | +16:18:23.3 | HIP 18227 | 14.44 |
| 2026-04-12 12:00 | 03:53:43.06 | +16:19:51.1 | HIP 18227 | 14.58 |
| 2026-04-13 00:00 | 03:54:03.35 | +16:21:18.8 | HIP 18227 | 16.37 |
| 2026-04-13 12:00 | 03:54:23.70 | +16:22:46.4 | HIP 18267 | 14.25 |
| 2026-04-14 00:00 | 03:54:44.13 | +16:24:13.9 | HIP 18267 | 13.34 |
| 2026-04-14 12:00 | 03:55:04.62 | +16:25:41.3 | HIP 18267 | 14.32 |
| 2026-04-15 00:00 | 03:55:25.18 | +16:27:08.6 | HIP 18267 | 16.89 |
| 2026-04-15 12:00 | 03:55:45.81 | +16:28:35.8 | HIP 18425 | 16.03 |
| 2026-04-16 00:00 | 03:56:06.50 | +16:30:02.9 | HIP 18425 | 15.26 |