249P/LINEAR
Metadata
| Parameter | Value |
|---|---|
| Designation | 249P/LINEAR |
| Type | P |
| Perihelion (tp_cal, UTC) | 2015-11-26T18:53:49.649280Z |
| Orbit solution date (soln_date, UTC) | 2023-01-03T10:14:16Z |
| Obs used | 884 |
| NEO | Yes |
| M1 | 18.400 |
| K1 | 4.500 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2014-07-25.0000000 |
| e | 0.81866843 |
| q (au) | 0.502345 |
| a (au) | 2.770312 |
| i (deg) | 8.399344 |
| Ω (om, deg) | 239.852044 |
| ω (w, deg) | 64.810358 |
| M (ma, deg) | 255.306758 |
Magnitude
Scatter + Global Linear
$$ M_a = (19.108 + 2.351\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 19.108 |
| n | 2.351 |
| gf | 1.000 |
| gb | -0.644 |
| k | 0.800 |
| 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 |
|---|---|---|---|
| 2020-01-25 | 2020-06-02 | +14.5622 | -0.412 |
| 2020-06-02 | 2020-08-01 | +43.3682 | +3.425 |
| 2020-08-01 | 2021-01-18 | -1.3785 | +0.228 |
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 | 06:53:47.88 | +17:20:12.0 | HIP 33203 | 24.23 |
| 2026-06-01 12:00 | 06:54:13.14 | +17:19:46.8 | HIP 33203 | 22.20 |
| 2026-06-02 00:00 | 06:54:38.44 | +17:19:21.2 | HIP 33230 | 21.07 |
| 2026-06-02 12:00 | 06:55:03.78 | +17:18:55.1 | HIP 33230 | 20.55 |
| 2026-06-03 00:00 | 06:55:29.16 | +17:18:28.4 | HIP 33230 | 21.78 |
| 2026-06-03 12:00 | 06:55:54.58 | +17:18:01.3 | HIP 33230 | 24.49 |
| 2026-06-04 00:00 | 06:56:20.03 | +17:17:33.6 | HIP 33358 | 26.69 |
| 2026-06-04 12:00 | 06:56:45.53 | +17:17:05.5 | HIP 33358 | 28.01 |
| 2026-06-05 00:00 | 06:57:11.06 | +17:16:36.8 | HIP 33583 | 23.80 |
| 2026-06-05 12:00 | 06:57:36.62 | +17:16:07.7 | HIP 33583 | 18.99 |
| 2026-06-06 00:00 | 06:58:02.22 | +17:15:38.0 | HIP 33583 | 15.16 |
| 2026-06-06 12:00 | 06:58:27.86 | +17:15:07.8 | HIP 33583 | 13.20 |
| 2026-06-07 00:00 | 06:58:53.52 | +17:14:37.2 | HIP 33583 | 13.93 |
| 2026-06-07 12:00 | 06:59:19.22 | +17:14:06.0 | HIP 33583 | 17.03 |
| 2026-06-08 00:00 | 06:59:44.96 | +17:13:34.4 | HIP 33752 | 20.60 |
| 2026-06-08 12:00 | 07:00:10.72 | +17:13:02.2 | HIP 33752 | 16.91 |
| 2026-06-09 00:00 | 07:00:36.51 | +17:12:29.5 | HIP 33752 | 14.95 |
| 2026-06-09 12:00 | 07:01:02.34 | +17:11:56.4 | HIP 33752 | 15.42 |
| 2026-06-10 00:00 | 07:01:28.19 | +17:11:22.7 | HIP 33752 | 18.13 |
| 2026-06-10 12:00 | 07:01:54.07 | +17:10:48.5 | HIP 33752 | 22.29 |
| 2026-06-11 00:00 | 07:02:19.98 | +17:10:13.9 | HIP 33752 | 27.24 |
| 2026-06-11 12:00 | 07:02:45.92 | +17:09:38.7 | HIP 34128 | 27.30 |
| 2026-06-12 00:00 | 07:03:11.88 | +17:09:03.0 | HIP 34128 | 21.18 |
| 2026-06-12 12:00 | 07:03:37.87 | +17:08:26.9 | HIP 34128 | 15.14 |
| 2026-06-13 00:00 | 07:04:03.88 | +17:07:50.2 | HIP 34128 | 9.34 |
| 2026-06-13 12:00 | 07:04:29.91 | +17:07:13.0 | HIP 34128 | 4.84 |
| 2026-06-14 00:00 | 07:04:55.97 | +17:06:35.4 | HIP 34128 | 6.14 |
| 2026-06-14 12:00 | 07:05:22.05 | +17:05:57.2 | HIP 34128 | 11.42 |
| 2026-06-15 00:00 | 07:05:48.15 | +17:05:18.5 | HIP 34128 | 17.37 |
| 2026-06-15 12:00 | 07:06:14.27 | +17:04:39.4 | HIP 34237 | 21.79 |
| 2026-06-16 00:00 | 07:06:40.41 | +17:03:59.7 | HIP 34237 | 24.74 |
| 2026-06-16 12:00 | 07:07:06.56 | +17:03:19.6 | HIP 34484 | 25.52 |
| 2026-06-17 00:00 | 07:07:32.74 | +17:02:38.9 | HIP 34484 | 19.47 |
| 2026-06-17 12:00 | 07:07:58.93 | +17:01:57.8 | HIP 34484 | 13.64 |
| 2026-06-18 00:00 | 07:08:25.13 | +17:01:16.2 | HIP 34484 | 8.49 |
| 2026-06-18 12:00 | 07:08:51.35 | +17:00:34.1 | HIP 34484 | 6.14 |
| 2026-06-19 00:00 | 07:09:17.59 | +16:59:51.5 | HIP 34484 | 9.10 |
| 2026-06-19 12:00 | 07:09:43.83 | +16:59:08.4 | HIP 34484 | 14.41 |
| 2026-06-20 00:00 | 07:10:10.09 | +16:58:24.8 | HIP 34484 | 20.31 |
| 2026-06-20 12:00 | 07:10:36.36 | +16:57:40.8 | HIP 34763 | 16.88 |
| 2026-06-21 00:00 | 07:11:02.64 | +16:56:56.2 | HIP 34763 | 10.70 |
| 2026-06-21 12:00 | 07:11:28.93 | +16:56:11.2 | HIP 34763 | 4.91 |
| 2026-06-22 00:00 | 07:11:55.23 | +16:55:25.7 | HIP 34763 | 3.74 |