291P/NEAT
| Parameter |
Value |
| Designation |
291P/NEAT |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2013-12-15T08:00:33.684480Z |
| Orbit solution date (soln_date, UTC) |
2024-05-30T01:12:35Z |
| Obs used |
950 |
| NEO |
- |
| M1 |
8.300 |
| K1 |
19.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-10-22.0000000 |
| e |
0.43049276 |
| q (au) |
2.591490 |
| a (au) |
4.550407 |
| i (deg) |
5.956694 |
| Ω (om, deg) |
241.044470 |
| ω (w, deg) |
176.028242 |
| M (ma, deg) |
317.421677 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.415 + 5.655\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.415 |
| n |
5.655 |
| gf |
0.936 |
| gb |
-0.768 |
| k |
0.973 |
| 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) |
| 2026-02-03 00:00 |
13:19:59.21 |
-13:30:52.8 |
HIP 64952 |
25.55 |
| 2026-02-03 12:00 |
13:19:58.07 |
-13:31:02.9 |
HIP 64952 |
25.49 |
| 2026-02-04 00:00 |
13:19:56.74 |
-13:31:12.0 |
HIP 64952 |
25.40 |
| 2026-02-04 12:00 |
13:19:55.24 |
-13:31:19.9 |
HIP 64952 |
25.26 |
| 2026-02-05 00:00 |
13:19:53.56 |
-13:31:26.7 |
HIP 64952 |
25.10 |
| 2026-02-05 12:00 |
13:19:51.70 |
-13:31:32.4 |
HIP 64952 |
24.90 |
| 2026-02-06 00:00 |
13:19:49.66 |
-13:31:37.0 |
HIP 64952 |
24.66 |
| 2026-02-06 12:00 |
13:19:47.45 |
-13:31:40.5 |
HIP 64952 |
24.39 |
| 2026-02-07 00:00 |
13:19:45.05 |
-13:31:42.8 |
HIP 64952 |
24.09 |
| 2026-02-07 12:00 |
13:19:42.47 |
-13:31:44.0 |
HIP 64952 |
23.77 |
| 2026-02-08 00:00 |
13:19:39.72 |
-13:31:44.1 |
HIP 64952 |
23.41 |
| 2026-02-08 12:00 |
13:19:36.79 |
-13:31:43.1 |
HIP 64952 |
23.03 |
| 2026-02-09 00:00 |
13:19:33.68 |
-13:31:40.9 |
HIP 64952 |
22.63 |
| 2026-02-09 12:00 |
13:19:30.39 |
-13:31:37.6 |
HIP 64952 |
22.22 |
| 2026-02-10 00:00 |
13:19:26.92 |
-13:31:33.1 |
HIP 64952 |
21.79 |
| 2026-02-10 12:00 |
13:19:23.27 |
-13:31:27.5 |
HIP 64952 |
21.35 |
| 2026-02-11 00:00 |
13:19:19.45 |
-13:31:20.7 |
HIP 64952 |
20.90 |
| 2026-02-11 12:00 |
13:19:15.45 |
-13:31:12.8 |
HIP 64952 |
20.46 |
| 2026-02-12 00:00 |
13:19:11.27 |
-13:31:03.8 |
HIP 64952 |
20.03 |
| 2026-02-12 12:00 |
13:19:06.92 |
-13:30:53.6 |
HIP 64952 |
19.61 |
| 2026-02-13 00:00 |
13:19:02.38 |
-13:30:42.3 |
HIP 64952 |
19.22 |
| 2026-02-13 12:00 |
13:18:57.68 |
-13:30:29.8 |
HIP 64952 |
18.86 |
| 2026-02-14 00:00 |
13:18:52.80 |
-13:30:16.1 |
HIP 64952 |
18.54 |
| 2026-02-14 12:00 |
13:18:47.74 |
-13:30:01.3 |
HIP 64952 |
18.29 |
| 2026-02-15 00:00 |
13:18:42.51 |
-13:29:45.4 |
HIP 64952 |
18.10 |
| 2026-02-15 12:00 |
13:18:37.10 |
-13:29:28.2 |
HIP 64952 |
17.99 |
| 2026-02-16 00:00 |
13:18:31.52 |
-13:29:10.0 |
HIP 64952 |
17.98 |
| 2026-02-16 12:00 |
13:18:25.77 |
-13:28:50.6 |
HIP 64952 |
18.06 |
| 2026-02-17 00:00 |
13:18:19.85 |
-13:28:30.0 |
HIP 64952 |
18.26 |
| 2026-02-17 12:00 |
13:18:13.75 |
-13:28:08.2 |
HIP 64952 |
18.58 |
| 2026-02-18 00:00 |
13:18:07.48 |
-13:27:45.4 |
HIP 64952 |
19.02 |
| 2026-02-18 12:00 |
13:18:01.05 |
-13:27:21.3 |
HIP 64952 |
19.59 |
| 2026-02-19 00:00 |
13:17:54.44 |
-13:26:56.1 |
HIP 64952 |
20.28 |
| 2026-02-19 12:00 |
13:17:47.67 |
-13:26:29.8 |
HIP 64808 |
20.76 |
| 2026-02-20 00:00 |
13:17:40.73 |
-13:26:02.3 |
HIP 64808 |
19.45 |
| 2026-02-20 12:00 |
13:17:33.62 |
-13:25:33.7 |
HIP 64808 |
18.17 |
| 2026-02-21 00:00 |
13:17:26.35 |
-13:25:03.9 |
HIP 64808 |
16.95 |
| 2026-02-21 12:00 |
13:17:18.92 |
-13:24:33.0 |
HIP 64808 |
15.82 |
| 2026-02-22 00:00 |
13:17:11.32 |
-13:24:00.9 |
HIP 64808 |
14.82 |
| 2026-02-22 12:00 |
13:17:03.56 |
-13:23:27.7 |
HIP 64808 |
13.99 |
| 2026-02-23 00:00 |
13:16:55.63 |
-13:22:53.4 |
HIP 64808 |
13.38 |
| 2026-02-23 12:00 |
13:16:47.55 |
-13:22:17.9 |
HIP 64808 |
13.04 |
| 2026-02-24 00:00 |
13:16:39.31 |
-13:21:41.3 |
HIP 64808 |
13.02 |