309P/LINEAR
| Parameter |
Value |
| Designation |
309P/LINEAR |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-02-16T06:54:37.134720Z |
| Orbit solution date (soln_date, UTC) |
2025-04-11T14:45:16Z |
| Obs used |
444 |
| NEO |
- |
| M1 |
16.200 |
| K1 |
6.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-11-28.0000000 |
| e |
0.60799848 |
| q (au) |
1.743209 |
| a (au) |
4.446944 |
| i (deg) |
17.665058 |
| Ω (om, deg) |
11.445885 |
| ω (w, deg) |
50.795718 |
| M (ma, deg) |
236.369621 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.080 + 2.428\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.080 |
| n |
2.428 |
| gf |
1.000 |
| gb |
-0.905 |
| k |
0.999 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
13:49:34.96 |
-14:39:57.0 |
HIP 67445 |
6.78 |
| 2026-02-03 12:00 |
13:49:34.39 |
-14:40:49.9 |
HIP 67445 |
5.97 |
| 2026-02-04 00:00 |
13:49:33.62 |
-14:41:41.9 |
HIP 67445 |
5.16 |
| 2026-02-04 12:00 |
13:49:32.65 |
-14:42:32.8 |
HIP 67445 |
4.37 |
| 2026-02-05 00:00 |
13:49:31.47 |
-14:43:22.8 |
HIP 67445 |
3.59 |
| 2026-02-05 12:00 |
13:49:30.09 |
-14:44:11.7 |
HIP 67445 |
2.84 |
| 2026-02-06 00:00 |
13:49:28.51 |
-14:44:59.5 |
HIP 67445 |
2.14 |
| 2026-02-06 12:00 |
13:49:26.73 |
-14:45:46.4 |
HIP 67445 |
1.58 |
| 2026-02-07 00:00 |
13:49:24.74 |
-14:46:32.2 |
HIP 67445 |
1.38 |
| 2026-02-07 12:00 |
13:49:22.54 |
-14:47:16.9 |
HIP 67445 |
1.67 |
| 2026-02-08 00:00 |
13:49:20.14 |
-14:48:00.6 |
HIP 67445 |
2.30 |
| 2026-02-08 12:00 |
13:49:17.54 |
-14:48:43.3 |
HIP 67445 |
3.08 |
| 2026-02-09 00:00 |
13:49:14.74 |
-14:49:24.9 |
HIP 67445 |
3.93 |
| 2026-02-09 12:00 |
13:49:11.72 |
-14:50:05.5 |
HIP 67445 |
4.83 |
| 2026-02-10 00:00 |
13:49:08.51 |
-14:50:45.0 |
HIP 67445 |
5.78 |
| 2026-02-10 12:00 |
13:49:05.08 |
-14:51:23.4 |
HIP 67445 |
6.75 |
| 2026-02-11 00:00 |
13:49:01.46 |
-14:52:00.8 |
HIP 67445 |
7.76 |
| 2026-02-11 12:00 |
13:48:57.63 |
-14:52:37.1 |
HIP 67445 |
8.80 |
| 2026-02-12 00:00 |
13:48:53.59 |
-14:53:12.4 |
HIP 67407 |
9.69 |
| 2026-02-12 12:00 |
13:48:49.35 |
-14:53:46.5 |
HIP 67407 |
10.31 |
| 2026-02-13 00:00 |
13:48:44.90 |
-14:54:19.6 |
HIP 67407 |
11.01 |
| 2026-02-13 12:00 |
13:48:40.25 |
-14:54:51.6 |
HIP 67407 |
11.79 |
| 2026-02-14 00:00 |
13:48:35.39 |
-14:55:22.6 |
HIP 67407 |
12.64 |
| 2026-02-14 12:00 |
13:48:30.33 |
-14:55:52.4 |
HIP 67407 |
13.57 |
| 2026-02-15 00:00 |
13:48:25.06 |
-14:56:21.2 |
HIP 67407 |
14.57 |
| 2026-02-15 12:00 |
13:48:19.59 |
-14:56:48.8 |
HIP 67407 |
15.63 |
| 2026-02-16 00:00 |
13:48:13.92 |
-14:57:15.4 |
HIP 67407 |
16.75 |
| 2026-02-16 12:00 |
13:48:08.04 |
-14:57:40.9 |
HIP 67407 |
17.93 |
| 2026-02-17 00:00 |
13:48:01.96 |
-14:58:05.3 |
HIP 67407 |
19.18 |
| 2026-02-17 12:00 |
13:47:55.68 |
-14:58:28.6 |
HIP 67407 |
20.48 |
| 2026-02-18 00:00 |
13:47:49.19 |
-14:58:50.7 |
HIP 67407 |
21.84 |
| 2026-02-18 12:00 |
13:47:42.50 |
-14:59:11.8 |
HIP 67407 |
23.25 |
| 2026-02-19 00:00 |
13:47:35.61 |
-14:59:31.8 |
HIP 67407 |
24.72 |
| 2026-02-19 12:00 |
13:47:28.52 |
-14:59:50.7 |
HIP 67407 |
26.25 |
| 2026-02-20 00:00 |
13:47:21.23 |
-15:00:08.5 |
HIP 67407 |
27.82 |
| 2026-02-20 12:00 |
13:47:13.74 |
-15:00:25.2 |
HIP 67407 |
29.45 |
| 2026-02-21 00:00 |
13:47:06.06 |
-15:00:40.8 |
HIP 67407 |
31.14 |
| 2026-02-21 12:00 |
13:46:58.17 |
-15:00:55.3 |
HIP 67097 |
30.35 |
| 2026-02-22 00:00 |
13:46:50.09 |
-15:01:08.6 |
HIP 67097 |
28.78 |
| 2026-02-22 12:00 |
13:46:41.81 |
-15:01:20.9 |
HIP 67097 |
27.22 |
| 2026-02-23 00:00 |
13:46:33.34 |
-15:01:32.1 |
HIP 67097 |
25.66 |
| 2026-02-23 12:00 |
13:46:24.67 |
-15:01:42.2 |
HIP 67097 |
24.14 |
| 2026-02-24 00:00 |
13:46:15.81 |
-15:01:51.2 |
HIP 67097 |
22.66 |