| Parameter |
Value |
| Designation |
502P/NEAT |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2025-08-05T23:40:46.439040Z |
| Orbit solution date (soln_date, UTC) |
2026-03-12T02:46:43Z |
| Obs used |
281 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
15.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2025-04-23T10:52:57.561600Z |
| Discovery magnitude (MPC) |
20.32 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-10-06.0000000 |
| e |
0.47091682 |
| q (au) |
4.259801 |
| a (au) |
8.051288 |
| i (deg) |
11.386402 |
| Ω (om, deg) |
264.572232 |
| ω (w, deg) |
37.192514 |
| M (ma, deg) |
236.569669 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.043 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.043 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.725 |
| k |
0.800 |
| δ90 |
9.999 |
| 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 |
| 2024-07-01 |
2025-08-05 |
+24.7671 |
-15.558 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
23:20:19.14 |
+07:28:16.3 |
HIP 115137 |
21.19 |
| 2026-06-01 12:00 |
23:20:34.74 |
+07:31:12.7 |
HIP 115356 |
20.54 |
| 2026-06-02 00:00 |
23:20:50.19 |
+07:34:08.4 |
HIP 115356 |
16.30 |
| 2026-06-02 12:00 |
23:21:05.49 |
+07:37:03.5 |
HIP 115356 |
12.53 |
| 2026-06-03 00:00 |
23:21:20.65 |
+07:39:57.9 |
HIP 115356 |
9.73 |
| 2026-06-03 12:00 |
23:21:35.65 |
+07:42:51.6 |
HIP 115356 |
8.81 |
| 2026-06-04 00:00 |
23:21:50.51 |
+07:45:44.6 |
HIP 115356 |
10.24 |
| 2026-06-04 12:00 |
23:22:05.21 |
+07:48:36.9 |
HIP 115356 |
13.24 |
| 2026-06-05 00:00 |
23:22:19.76 |
+07:51:28.5 |
HIP 115356 |
16.97 |
| 2026-06-05 12:00 |
23:22:34.16 |
+07:54:19.4 |
HIP 115393 |
19.20 |
| 2026-06-06 00:00 |
23:22:48.41 |
+07:57:09.6 |
HIP 115393 |
16.89 |
| 2026-06-06 12:00 |
23:23:02.50 |
+07:59:59.0 |
HIP 115393 |
15.58 |
| 2026-06-07 00:00 |
23:23:16.44 |
+08:02:47.7 |
HIP 115393 |
15.48 |
| 2026-06-07 12:00 |
23:23:30.22 |
+08:05:35.7 |
HIP 115393 |
16.59 |
| 2026-06-08 00:00 |
23:23:43.85 |
+08:08:22.9 |
HIP 115393 |
18.67 |
| 2026-06-08 12:00 |
23:23:57.31 |
+08:11:09.4 |
HIP 115393 |
21.41 |
| 2026-06-09 00:00 |
23:24:10.62 |
+08:13:55.1 |
HIP 115589 |
23.12 |
| 2026-06-09 12:00 |
23:24:23.77 |
+08:16:40.0 |
HIP 115589 |
24.63 |
| 2026-06-10 00:00 |
23:24:36.77 |
+08:19:24.1 |
HIP 115589 |
26.72 |
| 2026-06-10 12:00 |
23:24:49.60 |
+08:22:07.4 |
HIP 115589 |
29.27 |
| 2026-06-11 00:00 |
23:25:02.26 |
+08:24:50.0 |
HIP 115697 |
25.19 |
| 2026-06-11 12:00 |
23:25:14.77 |
+08:27:31.7 |
HIP 115697 |
21.13 |
| 2026-06-12 00:00 |
23:25:27.12 |
+08:30:12.6 |
HIP 115697 |
17.14 |
| 2026-06-12 12:00 |
23:25:39.30 |
+08:32:52.7 |
HIP 115697 |
13.23 |
| 2026-06-13 00:00 |
23:25:51.31 |
+08:35:31.9 |
HIP 115697 |
9.46 |
| 2026-06-13 12:00 |
23:26:03.16 |
+08:38:10.3 |
HIP 115697 |
6.02 |
| 2026-06-14 00:00 |
23:26:14.84 |
+08:40:47.9 |
HIP 115697 |
3.77 |
| 2026-06-14 12:00 |
23:26:26.36 |
+08:43:24.6 |
HIP 115697 |
4.75 |
| 2026-06-15 00:00 |
23:26:37.71 |
+08:46:00.4 |
HIP 115697 |
7.77 |
| 2026-06-15 12:00 |
23:26:48.89 |
+08:48:35.3 |
HIP 115680 |
10.39 |
| 2026-06-16 00:00 |
23:26:59.90 |
+08:51:09.4 |
HIP 115680 |
12.07 |
| 2026-06-16 12:00 |
23:27:10.74 |
+08:53:42.5 |
HIP 115680 |
14.49 |
| 2026-06-17 00:00 |
23:27:21.41 |
+08:56:14.8 |
HIP 115680 |
17.33 |
| 2026-06-17 12:00 |
23:27:31.91 |
+08:58:46.1 |
HIP 115680 |
20.39 |
| 2026-06-18 00:00 |
23:27:42.24 |
+09:01:16.5 |
HIP 115680 |
23.56 |
| 2026-06-18 12:00 |
23:27:52.40 |
+09:03:46.0 |
HIP 115871 |
23.91 |
| 2026-06-19 00:00 |
23:28:02.38 |
+09:06:14.6 |
HIP 115871 |
20.69 |
| 2026-06-19 12:00 |
23:28:12.19 |
+09:08:42.2 |
HIP 115871 |
17.59 |
| 2026-06-20 00:00 |
23:28:21.83 |
+09:11:08.9 |
HIP 115871 |
14.68 |
| 2026-06-20 12:00 |
23:28:31.29 |
+09:13:34.6 |
HIP 115871 |
12.05 |
| 2026-06-21 00:00 |
23:28:40.58 |
+09:15:59.3 |
HIP 115871 |
9.89 |
| 2026-06-21 12:00 |
23:28:49.70 |
+09:18:23.1 |
HIP 115871 |
8.50 |
| 2026-06-22 00:00 |
23:28:58.64 |
+09:20:45.9 |
HIP 115871 |
8.25 |