| Parameter |
Value |
| Designation |
246P/NEAT |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2013-01-28T15:13:27.269760Z |
| Orbit solution date (soln_date, UTC) |
2024-12-26T20:12:42Z |
| Obs used |
4914 |
| NEO |
- |
| M1 |
5.900 |
| K1 |
14.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-05-21.0000000 |
| e |
0.28504446 |
| q (au) |
2.879720 |
| a (au) |
4.027832 |
| i (deg) |
15.971716 |
| Ω (om, deg) |
78.780536 |
| ω (w, deg) |
176.171718 |
| M (ma, deg) |
13.700320 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.725 + 4.555\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.725 |
| n |
4.555 |
| gf |
0.995 |
| gb |
-0.502 |
| k |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2018-12-16 |
2020-04-22 |
-9.1189 |
+4.406 |
| 2020-04-22 |
2021-02-25 |
+4.2940 |
-2.300 |
| 2021-02-25 |
2019-09-03 |
+3.5698 |
-2.201 |
| 2019-09-03 |
2024-12-07 |
+8.2838 |
-4.696 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
07:51:57.59 |
+30:07:20.1 |
HIP 38480 |
12.01 |
| 2026-07-29 12:00 |
07:52:28.66 |
+30:06:39.0 |
HIP 38480 |
6.01 |
| 2026-07-30 00:00 |
07:52:59.70 |
+30:05:57.8 |
HIP 38480 |
4.36 |
| 2026-07-30 12:00 |
07:53:30.73 |
+30:05:16.6 |
HIP 38480 |
9.64 |
| 2026-07-31 00:00 |
07:54:01.74 |
+30:04:35.4 |
HIP 38480 |
16.05 |
| 2026-07-31 12:00 |
07:54:32.73 |
+30:03:54.2 |
HIP 38643 |
16.85 |
| 2026-08-01 00:00 |
07:55:03.70 |
+30:03:13.0 |
HIP 38643 |
17.72 |
| 2026-08-01 12:00 |
07:55:34.66 |
+30:02:31.7 |
HIP 38778 |
14.44 |
| 2026-08-02 00:00 |
07:56:05.59 |
+30:01:50.5 |
HIP 38778 |
10.93 |
| 2026-08-02 12:00 |
07:56:36.50 |
+30:01:09.2 |
HIP 38778 |
11.01 |
| 2026-08-03 00:00 |
07:57:07.39 |
+30:00:28.0 |
HIP 38778 |
14.62 |
| 2026-08-03 12:00 |
07:57:38.26 |
+29:59:46.7 |
HIP 38778 |
19.91 |
| 2026-08-04 00:00 |
07:58:09.11 |
+29:59:05.5 |
HIP 38778 |
25.87 |
| 2026-08-04 12:00 |
07:58:39.93 |
+29:58:24.3 |
HIP 38921 |
29.16 |
| 2026-08-05 00:00 |
07:59:10.73 |
+29:57:43.0 |
HIP 39047 |
29.30 |
| 2026-08-05 12:00 |
07:59:41.51 |
+29:57:01.8 |
HIP 39200 |
26.04 |
| 2026-08-06 00:00 |
08:00:12.26 |
+29:56:20.7 |
HIP 39200 |
22.42 |
| 2026-08-06 12:00 |
08:00:42.99 |
+29:55:39.5 |
HIP 39200 |
20.41 |
| 2026-08-07 00:00 |
08:01:13.69 |
+29:54:58.4 |
HIP 39233 |
19.35 |
| 2026-08-07 12:00 |
08:01:44.36 |
+29:54:17.3 |
HIP 39233 |
18.82 |
| 2026-08-08 00:00 |
08:02:15.01 |
+29:53:36.3 |
HIP 39233 |
20.58 |
| 2026-08-08 12:00 |
08:02:45.63 |
+29:52:55.3 |
HIP 39233 |
24.13 |
| 2026-08-09 00:00 |
08:03:16.22 |
+29:52:14.3 |
HIP 39233 |
28.81 |
| 2026-08-09 12:00 |
08:03:46.78 |
+29:51:33.4 |
HIP 39233 |
34.15 |
| 2026-08-10 00:00 |
08:04:17.31 |
+29:50:52.6 |
HIP 39614 |
39.05 |
| 2026-08-10 12:00 |
08:04:47.80 |
+29:50:11.8 |
HIP 39614 |
35.67 |
| 2026-08-11 00:00 |
08:05:18.27 |
+29:49:31.1 |
HIP 39614 |
33.31 |
| 2026-08-11 12:00 |
08:05:48.70 |
+29:48:50.4 |
HIP 39614 |
32.18 |
| 2026-08-12 00:00 |
08:06:19.10 |
+29:48:09.9 |
HIP 39614 |
32.40 |
| 2026-08-12 12:00 |
08:06:49.47 |
+29:47:29.4 |
HIP 39614 |
33.94 |
| 2026-08-13 00:00 |
08:07:19.80 |
+29:46:49.0 |
HIP 39614 |
36.64 |
| 2026-08-13 12:00 |
08:07:50.09 |
+29:46:08.7 |
HIP 39939 |
39.92 |
| 2026-08-14 00:00 |
08:08:20.35 |
+29:45:28.5 |
HIP 39939 |
37.66 |
| 2026-08-14 12:00 |
08:08:50.57 |
+29:44:48.3 |
HIP 39939 |
36.46 |
| 2026-08-15 00:00 |
08:09:20.75 |
+29:44:08.3 |
HIP 39939 |
36.43 |
| 2026-08-15 12:00 |
08:09:50.90 |
+29:43:28.4 |
HIP 39985 |
36.00 |
| 2026-08-16 00:00 |
08:10:21.00 |
+29:42:48.6 |
HIP 40209 |
32.82 |
| 2026-08-16 12:00 |
08:10:51.07 |
+29:42:09.0 |
HIP 40209 |
26.45 |
| 2026-08-17 00:00 |
08:11:21.09 |
+29:41:29.4 |
HIP 40209 |
20.21 |
| 2026-08-17 12:00 |
08:11:51.07 |
+29:40:50.0 |
HIP 40209 |
14.27 |
| 2026-08-18 00:00 |
08:12:21.01 |
+29:40:10.7 |
HIP 40209 |
9.20 |
| 2026-08-18 12:00 |
08:12:50.91 |
+29:39:31.5 |
HIP 40240 |
3.91 |
| 2026-08-19 00:00 |
08:13:20.76 |
+29:38:52.5 |
HIP 40240 |
2.63 |