| 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) |
| 2026-03-26 00:00 |
13:32:20.32 |
-14:38:24.7 |
HIP 65983 |
39.44 |
| 2026-03-26 12:00 |
13:32:02.49 |
-14:37:31.7 |
HIP 65983 |
39.49 |
| 2026-03-27 00:00 |
13:31:44.58 |
-14:36:37.8 |
HIP 65845 |
39.61 |
| 2026-03-27 12:00 |
13:31:26.59 |
-14:35:43.2 |
HIP 65845 |
37.45 |
| 2026-03-28 00:00 |
13:31:08.53 |
-14:34:47.8 |
HIP 65845 |
35.71 |
| 2026-03-28 12:00 |
13:30:50.40 |
-14:33:51.6 |
HIP 65845 |
34.47 |
| 2026-03-29 00:00 |
13:30:32.21 |
-14:32:54.6 |
HIP 65845 |
33.80 |
| 2026-03-29 12:00 |
13:30:13.94 |
-14:31:56.9 |
HIP 65856 |
32.08 |
| 2026-03-30 00:00 |
13:29:55.62 |
-14:30:58.5 |
HIP 65856 |
30.89 |
| 2026-03-30 12:00 |
13:29:37.23 |
-14:29:59.3 |
HIP 65856 |
30.34 |
| 2026-03-31 00:00 |
13:29:18.79 |
-14:28:59.4 |
HIP 65856 |
30.45 |
| 2026-03-31 12:00 |
13:29:00.29 |
-14:27:58.9 |
HIP 65856 |
31.24 |
| 2026-04-01 00:00 |
13:28:41.75 |
-14:26:57.6 |
HIP 65856 |
32.67 |
| 2026-04-01 12:00 |
13:28:23.15 |
-14:25:55.6 |
HIP 65856 |
34.65 |
| 2026-04-02 00:00 |
13:28:04.51 |
-14:24:53.0 |
HIP 65548 |
35.07 |
| 2026-04-02 12:00 |
13:27:45.82 |
-14:23:49.7 |
HIP 65548 |
32.53 |
| 2026-04-03 00:00 |
13:27:27.09 |
-14:22:45.7 |
HIP 65548 |
30.48 |
| 2026-04-03 12:00 |
13:27:08.33 |
-14:21:41.2 |
HIP 65548 |
29.04 |
| 2026-04-04 00:00 |
13:26:49.53 |
-14:20:36.0 |
HIP 65548 |
28.32 |
| 2026-04-04 12:00 |
13:26:30.70 |
-14:19:30.2 |
HIP 65548 |
28.37 |
| 2026-04-05 00:00 |
13:26:11.84 |
-14:18:23.8 |
HIP 65548 |
29.19 |
| 2026-04-05 12:00 |
13:25:52.95 |
-14:17:16.8 |
HIP 65548 |
30.72 |
| 2026-04-06 00:00 |
13:25:34.03 |
-14:16:09.3 |
HIP 65362 |
29.74 |
| 2026-04-06 12:00 |
13:25:15.10 |
-14:15:01.1 |
HIP 65362 |
25.15 |
| 2026-04-07 00:00 |
13:24:56.15 |
-14:13:52.5 |
HIP 65362 |
20.63 |
| 2026-04-07 12:00 |
13:24:37.18 |
-14:12:43.3 |
HIP 65362 |
16.21 |
| 2026-04-08 00:00 |
13:24:18.20 |
-14:11:33.6 |
HIP 65362 |
12.03 |
| 2026-04-08 12:00 |
13:23:59.21 |
-14:10:23.4 |
HIP 65362 |
8.46 |
| 2026-04-09 00:00 |
13:23:40.21 |
-14:09:12.7 |
HIP 65362 |
6.60 |
| 2026-04-09 12:00 |
13:23:21.21 |
-14:08:01.6 |
HIP 65362 |
7.79 |
| 2026-04-10 00:00 |
13:23:02.21 |
-14:06:50.0 |
HIP 65362 |
11.09 |
| 2026-04-10 12:00 |
13:22:43.21 |
-14:05:37.9 |
HIP 65362 |
15.18 |
| 2026-04-11 00:00 |
13:22:24.21 |
-14:04:25.4 |
HIP 65362 |
19.58 |
| 2026-04-11 12:00 |
13:22:05.22 |
-14:03:12.5 |
HIP 65235 |
21.98 |
| 2026-04-12 00:00 |
13:21:46.24 |
-14:01:59.2 |
HIP 65235 |
23.71 |
| 2026-04-12 12:00 |
13:21:27.27 |
-14:00:45.5 |
HIP 65235 |
26.20 |
| 2026-04-13 00:00 |
13:21:08.32 |
-13:59:31.4 |
HIP 65235 |
29.27 |
| 2026-04-13 12:00 |
13:20:49.39 |
-13:58:17.0 |
HIP 65235 |
32.74 |
| 2026-04-14 00:00 |
13:20:30.48 |
-13:57:02.3 |
HIP 65235 |
36.51 |
| 2026-04-14 12:00 |
13:20:11.60 |
-13:55:47.2 |
HIP 64878 |
33.89 |
| 2026-04-15 00:00 |
13:19:52.74 |
-13:54:31.9 |
HIP 64878 |
29.88 |
| 2026-04-15 12:00 |
13:19:33.91 |
-13:53:16.2 |
HIP 64878 |
26.11 |
| 2026-04-16 00:00 |
13:19:15.12 |
-13:52:00.3 |
HIP 64878 |
22.73 |