| 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) |
| 2026-05-12 00:00 |
13:04:47.31 |
-12:46:39.2 |
HIP 63709 |
24.01 |
| 2026-05-12 12:00 |
13:04:33.73 |
-12:45:31.3 |
HIP 63709 |
21.90 |
| 2026-05-13 00:00 |
13:04:20.30 |
-12:44:24.0 |
HIP 63709 |
20.20 |
| 2026-05-13 12:00 |
13:04:07.02 |
-12:43:17.3 |
HIP 63709 |
18.99 |
| 2026-05-14 00:00 |
13:03:53.89 |
-12:42:11.0 |
HIP 63709 |
18.36 |
| 2026-05-14 12:00 |
13:03:40.92 |
-12:41:05.4 |
HIP 63709 |
18.34 |
| 2026-05-15 00:00 |
13:03:28.09 |
-12:40:00.3 |
HIP 63709 |
18.91 |
| 2026-05-15 12:00 |
13:03:15.43 |
-12:38:55.9 |
HIP 63709 |
20.01 |
| 2026-05-16 00:00 |
13:03:02.92 |
-12:37:52.0 |
HIP 63709 |
21.54 |
| 2026-05-16 12:00 |
13:02:50.56 |
-12:36:48.7 |
HIP 63543 |
23.12 |
| 2026-05-17 00:00 |
13:02:38.37 |
-12:35:46.1 |
HIP 63543 |
20.18 |
| 2026-05-17 12:00 |
13:02:26.34 |
-12:34:44.1 |
HIP 63543 |
17.36 |
| 2026-05-18 00:00 |
13:02:14.46 |
-12:33:42.8 |
HIP 63543 |
14.70 |
| 2026-05-18 12:00 |
13:02:02.76 |
-12:32:42.1 |
HIP 63543 |
12.26 |
| 2026-05-19 00:00 |
13:01:51.21 |
-12:31:42.2 |
HIP 63543 |
10.17 |
| 2026-05-19 12:00 |
13:01:39.83 |
-12:30:42.9 |
HIP 63543 |
8.65 |
| 2026-05-20 00:00 |
13:01:28.61 |
-12:29:44.2 |
HIP 63543 |
7.97 |
| 2026-05-20 12:00 |
13:01:17.56 |
-12:28:46.3 |
HIP 63543 |
8.31 |
| 2026-05-21 00:00 |
13:01:06.68 |
-12:27:49.1 |
HIP 63543 |
9.52 |
| 2026-05-21 12:00 |
13:00:55.97 |
-12:26:52.7 |
HIP 63543 |
11.29 |
| 2026-05-22 00:00 |
13:00:45.42 |
-12:25:56.9 |
HIP 63543 |
13.37 |
| 2026-05-22 12:00 |
13:00:35.04 |
-12:25:01.9 |
HIP 63543 |
15.62 |
| 2026-05-23 00:00 |
13:00:24.84 |
-12:24:07.7 |
HIP 63543 |
17.96 |
| 2026-05-23 12:00 |
13:00:14.80 |
-12:23:14.2 |
HIP 63543 |
20.33 |
| 2026-05-24 00:00 |
13:00:04.93 |
-12:22:21.4 |
HIP 63543 |
22.71 |
| 2026-05-24 12:00 |
12:59:55.24 |
-12:21:29.4 |
HIP 63313 |
22.58 |
| 2026-05-25 00:00 |
12:59:45.71 |
-12:20:38.2 |
HIP 63313 |
20.89 |
| 2026-05-25 12:00 |
12:59:36.36 |
-12:19:47.8 |
HIP 63313 |
19.39 |
| 2026-05-26 00:00 |
12:59:27.19 |
-12:18:58.2 |
HIP 63313 |
18.12 |
| 2026-05-26 12:00 |
12:59:18.18 |
-12:18:09.4 |
HIP 63313 |
17.11 |
| 2026-05-27 00:00 |
12:59:09.35 |
-12:17:21.4 |
HIP 63313 |
16.39 |
| 2026-05-27 12:00 |
12:59:00.69 |
-12:16:34.2 |
HIP 63313 |
15.97 |
| 2026-05-28 00:00 |
12:58:52.21 |
-12:15:47.8 |
HIP 63313 |
15.88 |
| 2026-05-28 12:00 |
12:58:43.90 |
-12:15:02.2 |
HIP 63313 |
16.08 |
| 2026-05-29 00:00 |
12:58:35.76 |
-12:14:17.4 |
HIP 63313 |
16.55 |
| 2026-05-29 12:00 |
12:58:27.80 |
-12:13:33.5 |
HIP 63313 |
17.26 |
| 2026-05-30 00:00 |
12:58:20.02 |
-12:12:50.4 |
HIP 63313 |
18.16 |
| 2026-05-30 12:00 |
12:58:12.41 |
-12:12:08.2 |
HIP 63220 |
16.70 |
| 2026-05-31 00:00 |
12:58:04.98 |
-12:11:26.8 |
HIP 63220 |
14.78 |
| 2026-05-31 12:00 |
12:57:57.72 |
-12:10:46.3 |
HIP 63220 |
12.92 |
| 2026-06-01 00:00 |
12:57:50.63 |
-12:10:06.6 |
HIP 63220 |
11.10 |
| 2026-06-01 12:00 |
12:57:43.73 |
-12:09:27.8 |
HIP 63220 |
9.34 |
| 2026-06-02 00:00 |
12:57:37.00 |
-12:08:49.8 |
HIP 63220 |
7.65 |