| Parameter |
Value |
| Designation |
169P/NEAT |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-04-29T14:35:57.059520Z |
| Orbit solution date (soln_date, UTC) |
2026-09-21T07:12:14Z |
| Obs used |
2499 |
| NEO |
Yes |
| M1 |
17.600 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-09-23.0000000 |
| e |
0.76800014 |
| q (au) |
0.603807 |
| a (au) |
2.602618 |
| i (deg) |
11.295686 |
| Ω (om, deg) |
176.093534 |
| ω (w, deg) |
218.071790 |
| M (ma, deg) |
308.683727 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.699 + 5.360\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.699 |
| n |
5.360 |
| gf |
1.000 |
| gb |
-0.943 |
| k |
0.806 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
09:34:41.02 |
+07:41:41.6 |
HIP 46994 |
29.55 |
| 2026-09-20 12:00 |
09:35:13.52 |
+07:31:01.4 |
HIP 47158 |
30.91 |
| 2026-09-21 00:00 |
09:35:48.30 |
+07:20:31.8 |
HIP 47158 |
17.33 |
| 2026-09-21 12:00 |
09:36:25.29 |
+07:10:12.2 |
HIP 47158 |
3.53 |
| 2026-09-22 00:00 |
09:37:04.42 |
+07:00:02.3 |
HIP 47205 |
10.10 |
| 2026-09-22 12:00 |
09:37:45.60 |
+06:50:01.6 |
HIP 47205 |
8.17 |
| 2026-09-23 00:00 |
09:38:28.78 |
+06:40:09.7 |
HIP 47314 |
13.43 |
| 2026-09-23 12:00 |
09:39:13.88 |
+06:30:26.2 |
HIP 47396 |
3.44 |
| 2026-09-24 00:00 |
09:40:00.82 |
+06:20:50.6 |
HIP 47396 |
11.85 |
| 2026-09-24 12:00 |
09:40:49.54 |
+06:11:22.7 |
HIP 47396 |
27.18 |
| 2026-09-25 00:00 |
09:41:39.97 |
+06:02:02.0 |
HIP 47639 |
20.50 |
| 2026-09-25 12:00 |
09:42:32.05 |
+05:52:48.3 |
HIP 47639 |
4.60 |
| 2026-09-26 00:00 |
09:43:25.69 |
+05:43:41.2 |
HIP 47639 |
11.56 |
| 2026-09-26 12:00 |
09:44:20.84 |
+05:34:40.5 |
HIP 47639 |
27.98 |
| 2026-09-27 00:00 |
09:45:17.42 |
+05:25:45.8 |
HIP 47767 |
33.17 |
| 2026-09-27 12:00 |
09:46:15.38 |
+05:16:56.9 |
HIP 48044 |
26.36 |
| 2026-09-28 00:00 |
09:47:14.65 |
+05:08:13.5 |
HIP 48044 |
25.97 |
| 2026-09-28 12:00 |
09:48:15.15 |
+04:59:35.4 |
HIP 48261 |
33.66 |
| 2026-09-29 00:00 |
09:49:16.84 |
+04:51:02.3 |
HIP 48295 |
24.17 |
| 2026-09-29 12:00 |
09:50:19.65 |
+04:42:34.1 |
HIP 48295 |
17.84 |
| 2026-09-30 00:00 |
09:51:23.51 |
+04:34:10.6 |
HIP 48273 |
18.98 |
| 2026-09-30 12:00 |
09:52:28.38 |
+04:25:51.5 |
HIP 48475 |
12.30 |
| 2026-10-01 00:00 |
09:53:34.19 |
+04:17:36.8 |
HIP 48475 |
15.51 |
| 2026-10-01 12:00 |
09:54:40.87 |
+04:09:26.1 |
HIP 48609 |
8.22 |
| 2026-10-02 00:00 |
09:55:48.39 |
+04:01:19.5 |
HIP 48750 |
12.20 |
| 2026-10-02 12:00 |
09:56:56.69 |
+03:53:16.7 |
HIP 48772 |
5.09 |
| 2026-10-03 00:00 |
09:58:05.70 |
+03:45:17.7 |
HIP 48772 |
22.82 |
| 2026-10-03 12:00 |
09:59:15.39 |
+03:37:22.2 |
HIP 48990 |
15.87 |
| 2026-10-04 00:00 |
10:00:25.70 |
+03:29:30.3 |
HIP 48990 |
12.41 |
| 2026-10-04 12:00 |
10:01:36.58 |
+03:21:41.7 |
HIP 49213 |
24.82 |
| 2026-10-05 00:00 |
10:02:47.98 |
+03:13:56.5 |
HIP 49329 |
20.18 |
| 2026-10-05 12:00 |
10:03:59.87 |
+03:06:14.4 |
HIP 49329 |
6.22 |
| 2026-10-06 00:00 |
10:05:12.20 |
+02:58:35.5 |
HIP 49329 |
20.85 |
| 2026-10-06 12:00 |
10:06:24.92 |
+02:50:59.7 |
HIP 49544 |
10.54 |
| 2026-10-07 00:00 |
10:07:37.99 |
+02:43:26.8 |
HIP 49544 |
17.71 |
| 2026-10-07 12:00 |
10:08:51.38 |
+02:35:56.9 |
HIP 49756 |
15.87 |
| 2026-10-08 00:00 |
10:10:05.05 |
+02:28:29.9 |
HIP 49777 |
9.79 |
| 2026-10-08 12:00 |
10:11:18.95 |
+02:21:05.7 |
HIP 49777 |
24.87 |
| 2026-10-09 00:00 |
10:12:33.07 |
+02:13:44.3 |
HIP 50091 |
31.13 |
| 2026-10-09 12:00 |
10:13:47.35 |
+02:06:25.6 |
HIP 50091 |
33.79 |
| 2026-10-10 00:00 |
10:15:01.78 |
+01:59:09.6 |
HIP 50348 |
29.68 |
| 2026-10-10 12:00 |
10:16:16.32 |
+01:51:56.3 |
HIP 50348 |
9.72 |
| 2026-10-11 00:00 |
10:17:30.94 |
+01:44:45.7 |
HIP 50348 |
10.30 |