| Parameter |
Value |
| Designation |
439P/LINEAR |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2009-01-23T23:09:05.474880Z |
| Orbit solution date (soln_date, UTC) |
2022-02-05T22:46:18Z |
| Obs used |
154 |
| NEO |
- |
| M1 |
12.400 |
| K1 |
23.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2010-01-18.0000000 |
| e |
0.50983794 |
| q (au) |
1.646306 |
| a (au) |
3.358697 |
| i (deg) |
6.957515 |
| Ω (om, deg) |
59.100410 |
| ω (w, deg) |
337.647279 |
| M (ma, deg) |
57.489034 |
Magnitude
Scatter + Global Linear
$$
M_a = (18.779 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
18.779 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-0.897 |
| k |
0.992 |
| δ90 |
1.000 |
| 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) |
| 2026-07-29 00:00 |
16:30:48.61 |
-25:31:18.0 |
HIP 80844 |
4.49 |
| 2026-07-29 12:00 |
16:30:41.22 |
-25:31:02.5 |
HIP 80844 |
3.24 |
| 2026-07-30 00:00 |
16:30:34.10 |
-25:30:47.4 |
HIP 80844 |
2.56 |
| 2026-07-30 12:00 |
16:30:27.26 |
-25:30:32.7 |
HIP 80844 |
2.78 |
| 2026-07-31 00:00 |
16:30:20.69 |
-25:30:18.4 |
HIP 80844 |
3.67 |
| 2026-07-31 12:00 |
16:30:14.39 |
-25:30:04.6 |
HIP 80844 |
4.81 |
| 2026-08-01 00:00 |
16:30:08.38 |
-25:29:51.1 |
HIP 80844 |
6.02 |
| 2026-08-01 12:00 |
16:30:02.64 |
-25:29:38.1 |
HIP 80844 |
7.23 |
| 2026-08-02 00:00 |
16:29:57.17 |
-25:29:25.5 |
HIP 80844 |
8.42 |
| 2026-08-02 12:00 |
16:29:51.98 |
-25:29:13.4 |
HIP 80844 |
9.55 |
| 2026-08-03 00:00 |
16:29:47.07 |
-25:29:01.7 |
HIP 80844 |
10.64 |
| 2026-08-03 12:00 |
16:29:42.43 |
-25:28:50.4 |
HIP 80844 |
11.67 |
| 2026-08-04 00:00 |
16:29:38.07 |
-25:28:39.6 |
HIP 80844 |
12.65 |
| 2026-08-04 12:00 |
16:29:33.99 |
-25:28:29.2 |
HIP 80844 |
13.56 |
| 2026-08-05 00:00 |
16:29:30.19 |
-25:28:19.3 |
HIP 80844 |
14.42 |
| 2026-08-05 12:00 |
16:29:26.66 |
-25:28:09.9 |
HIP 80844 |
15.22 |
| 2026-08-06 00:00 |
16:29:23.42 |
-25:28:00.9 |
HIP 80673 |
15.45 |
| 2026-08-06 12:00 |
16:29:20.45 |
-25:27:52.4 |
HIP 80673 |
14.77 |
| 2026-08-07 00:00 |
16:29:17.75 |
-25:27:44.4 |
HIP 80673 |
14.16 |
| 2026-08-07 12:00 |
16:29:15.34 |
-25:27:36.8 |
HIP 80673 |
13.61 |
| 2026-08-08 00:00 |
16:29:13.20 |
-25:27:29.8 |
HIP 80673 |
13.12 |
| 2026-08-08 12:00 |
16:29:11.35 |
-25:27:23.2 |
HIP 80673 |
12.70 |
| 2026-08-09 00:00 |
16:29:09.77 |
-25:27:17.1 |
HIP 80673 |
12.35 |
| 2026-08-09 12:00 |
16:29:08.47 |
-25:27:11.5 |
HIP 80673 |
12.05 |
| 2026-08-10 00:00 |
16:29:07.45 |
-25:27:06.4 |
HIP 80673 |
11.82 |
| 2026-08-10 12:00 |
16:29:06.70 |
-25:27:01.8 |
HIP 80673 |
11.66 |
| 2026-08-11 00:00 |
16:29:06.24 |
-25:26:57.6 |
HIP 80673 |
11.55 |
| 2026-08-11 12:00 |
16:29:06.05 |
-25:26:54.0 |
HIP 80673 |
11.51 |
| 2026-08-12 00:00 |
16:29:06.14 |
-25:26:50.9 |
HIP 80673 |
11.53 |
| 2026-08-12 12:00 |
16:29:06.51 |
-25:26:48.3 |
HIP 80673 |
11.62 |
| 2026-08-13 00:00 |
16:29:07.16 |
-25:26:46.2 |
HIP 80673 |
11.77 |
| 2026-08-13 12:00 |
16:29:08.08 |
-25:26:44.7 |
HIP 80673 |
11.98 |
| 2026-08-14 00:00 |
16:29:09.28 |
-25:26:43.6 |
HIP 80673 |
12.25 |
| 2026-08-14 12:00 |
16:29:10.76 |
-25:26:43.0 |
HIP 80673 |
12.58 |
| 2026-08-15 00:00 |
16:29:12.51 |
-25:26:43.0 |
HIP 80673 |
12.98 |
| 2026-08-15 12:00 |
16:29:14.54 |
-25:26:43.4 |
HIP 80673 |
13.43 |
| 2026-08-16 00:00 |
16:29:16.84 |
-25:26:44.4 |
HIP 80673 |
13.95 |
| 2026-08-16 12:00 |
16:29:19.42 |
-25:26:45.9 |
HIP 80673 |
14.53 |
| 2026-08-17 00:00 |
16:29:22.27 |
-25:26:47.9 |
HIP 80673 |
15.17 |
| 2026-08-17 12:00 |
16:29:25.39 |
-25:26:50.4 |
HIP 80844 |
15.57 |
| 2026-08-18 00:00 |
16:29:28.78 |
-25:26:53.4 |
HIP 80844 |
14.80 |
| 2026-08-18 12:00 |
16:29:32.45 |
-25:26:57.0 |
HIP 80844 |
13.97 |
| 2026-08-19 00:00 |
16:29:36.38 |
-25:27:01.0 |
HIP 80844 |
13.08 |