| 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) |
| 2026-05-12 00:00 |
12:43:05.72 |
-09:34:13.0 |
HIP 62113 |
15.92 |
| 2026-05-12 12:00 |
12:42:56.39 |
-09:32:45.7 |
HIP 62113 |
18.55 |
| 2026-05-13 00:00 |
12:42:47.20 |
-09:31:19.1 |
HIP 62113 |
21.17 |
| 2026-05-13 12:00 |
12:42:38.15 |
-09:29:53.3 |
HIP 62113 |
23.77 |
| 2026-05-14 00:00 |
12:42:29.25 |
-09:28:28.2 |
HIP 61903 |
24.11 |
| 2026-05-14 12:00 |
12:42:20.49 |
-09:27:03.9 |
HIP 61903 |
21.54 |
| 2026-05-15 00:00 |
12:42:11.87 |
-09:25:40.3 |
HIP 61903 |
19.00 |
| 2026-05-15 12:00 |
12:42:03.40 |
-09:24:17.5 |
HIP 61903 |
16.49 |
| 2026-05-16 00:00 |
12:41:55.08 |
-09:22:55.5 |
HIP 61903 |
14.03 |
| 2026-05-16 12:00 |
12:41:46.90 |
-09:21:34.3 |
HIP 61903 |
11.60 |
| 2026-05-17 00:00 |
12:41:38.88 |
-09:20:13.9 |
HIP 61903 |
9.21 |
| 2026-05-17 12:00 |
12:41:31.00 |
-09:18:54.3 |
HIP 61903 |
6.86 |
| 2026-05-18 00:00 |
12:41:23.27 |
-09:17:35.6 |
HIP 61903 |
4.55 |
| 2026-05-18 12:00 |
12:41:15.70 |
-09:16:17.7 |
HIP 61903 |
2.29 |
| 2026-05-19 00:00 |
12:41:08.27 |
-09:15:00.6 |
HIP 61903 |
0.32 |
| 2026-05-19 12:00 |
12:41:01.00 |
-09:13:44.4 |
HIP 61903 |
2.19 |
| 2026-05-20 00:00 |
12:40:53.88 |
-09:12:29.1 |
HIP 61903 |
4.34 |
| 2026-05-20 12:00 |
12:40:46.92 |
-09:11:14.6 |
HIP 61903 |
6.45 |
| 2026-05-21 00:00 |
12:40:40.10 |
-09:10:01.0 |
HIP 61903 |
8.53 |
| 2026-05-21 12:00 |
12:40:33.45 |
-09:08:48.2 |
HIP 61903 |
10.57 |
| 2026-05-22 00:00 |
12:40:26.94 |
-09:07:36.4 |
HIP 61903 |
12.57 |
| 2026-05-22 12:00 |
12:40:20.60 |
-09:06:25.4 |
HIP 61903 |
14.53 |
| 2026-05-23 00:00 |
12:40:14.41 |
-09:05:15.4 |
HIP 61903 |
16.45 |
| 2026-05-23 12:00 |
12:40:08.37 |
-09:04:06.2 |
HIP 61903 |
18.34 |
| 2026-05-24 00:00 |
12:40:02.50 |
-09:02:58.0 |
HIP 61903 |
20.18 |
| 2026-05-24 12:00 |
12:39:56.77 |
-09:01:50.7 |
HIP 61903 |
21.98 |
| 2026-05-25 00:00 |
12:39:51.21 |
-09:00:44.2 |
HIP 61903 |
23.74 |
| 2026-05-25 12:00 |
12:39:45.80 |
-08:59:38.8 |
HIP 61797 |
25.09 |
| 2026-05-26 00:00 |
12:39:40.55 |
-08:58:34.2 |
HIP 61797 |
24.19 |
| 2026-05-26 12:00 |
12:39:35.46 |
-08:57:30.6 |
HIP 61797 |
23.39 |
| 2026-05-27 00:00 |
12:39:30.53 |
-08:56:27.9 |
HIP 61797 |
22.68 |
| 2026-05-27 12:00 |
12:39:25.75 |
-08:55:26.2 |
HIP 61797 |
22.06 |
| 2026-05-28 00:00 |
12:39:21.14 |
-08:54:25.4 |
HIP 61797 |
21.54 |
| 2026-05-28 12:00 |
12:39:16.68 |
-08:53:25.5 |
HIP 61797 |
21.11 |
| 2026-05-29 00:00 |
12:39:12.38 |
-08:52:26.7 |
HIP 61797 |
20.78 |
| 2026-05-29 12:00 |
12:39:08.24 |
-08:51:28.7 |
HIP 61797 |
20.53 |
| 2026-05-30 00:00 |
12:39:04.25 |
-08:50:31.7 |
HIP 61797 |
20.36 |
| 2026-05-30 12:00 |
12:39:00.43 |
-08:49:35.7 |
HIP 61797 |
20.27 |
| 2026-05-31 00:00 |
12:38:56.76 |
-08:48:40.7 |
HIP 61797 |
20.25 |
| 2026-05-31 12:00 |
12:38:53.26 |
-08:47:46.6 |
HIP 61797 |
20.29 |
| 2026-06-01 00:00 |
12:38:49.91 |
-08:46:53.5 |
HIP 61797 |
20.39 |
| 2026-06-01 12:00 |
12:38:46.72 |
-08:46:01.4 |
HIP 61797 |
20.54 |
| 2026-06-02 00:00 |
12:38:43.69 |
-08:45:10.3 |
HIP 61797 |
20.72 |