496P/Hill
| Parameter |
Value |
| Designation |
496P/Hill |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2025-03-11T10:59:53.473920Z |
| Orbit solution date (soln_date, UTC) |
2025-09-30T13:39:54Z |
| Obs used |
1688 |
| NEO |
- |
| M1 |
11.200 |
| K1 |
20.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2024-09-26T14:11:19.680000Z |
| Discovery magnitude (MPC) |
20.22 G |
| Discovery observatory (MPC) |
F52 · Pan-STARRS 2, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-09-12.0000000 |
| e |
0.73348756 |
| q (au) |
1.620113 |
| a (au) |
6.078939 |
| i (deg) |
14.831238 |
| Ω (om, deg) |
63.817654 |
| ω (w, deg) |
42.159614 |
| M (ma, deg) |
276.059995 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.592 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.592 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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 |
| 2024-09-11 |
2024-11-06 |
+18.6955 |
-6.087 |
| 2024-11-06 |
2024-12-27 |
-5.6666 |
+2.049 |
| 2024-12-27 |
2025-03-11 |
+13.4429 |
-2.871 |
| 2025-03-14 |
2025-06-28 |
-8.8446 |
+1.243 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
15:20:09.42 |
-10:49:53.8 |
HIP 75075 |
13.19 |
| 2026-02-03 12:00 |
15:20:23.63 |
-10:50:44.0 |
HIP 75075 |
11.37 |
| 2026-02-04 00:00 |
15:20:37.60 |
-10:51:33.2 |
HIP 75075 |
10.52 |
| 2026-02-04 12:00 |
15:20:51.33 |
-10:52:21.3 |
HIP 75136 |
10.46 |
| 2026-02-05 00:00 |
15:21:04.81 |
-10:53:08.3 |
HIP 75136 |
9.58 |
| 2026-02-05 12:00 |
15:21:18.05 |
-10:53:54.3 |
HIP 75136 |
9.84 |
| 2026-02-06 00:00 |
15:21:31.04 |
-10:54:39.2 |
HIP 75136 |
11.11 |
| 2026-02-06 12:00 |
15:21:43.79 |
-10:55:23.0 |
HIP 75136 |
13.05 |
| 2026-02-07 00:00 |
15:21:56.28 |
-10:56:05.8 |
HIP 75136 |
15.37 |
| 2026-02-07 12:00 |
15:22:08.53 |
-10:56:47.5 |
HIP 75136 |
17.89 |
| 2026-02-08 00:00 |
15:22:20.52 |
-10:57:28.2 |
HIP 75253 |
18.27 |
| 2026-02-08 12:00 |
15:22:32.27 |
-10:58:07.8 |
HIP 75253 |
18.53 |
| 2026-02-09 00:00 |
15:22:43.76 |
-10:58:46.4 |
HIP 75253 |
19.21 |
| 2026-02-09 12:00 |
15:22:54.99 |
-10:59:24.0 |
HIP 75253 |
20.26 |
| 2026-02-10 00:00 |
15:23:05.97 |
-11:00:00.5 |
HIP 75419 |
21.33 |
| 2026-02-10 12:00 |
15:23:16.70 |
-11:00:35.9 |
HIP 75419 |
18.65 |
| 2026-02-11 00:00 |
15:23:27.16 |
-11:01:10.3 |
HIP 75419 |
16.04 |
| 2026-02-11 12:00 |
15:23:37.37 |
-11:01:43.7 |
HIP 75419 |
13.51 |
| 2026-02-12 00:00 |
15:23:47.31 |
-11:02:16.1 |
HIP 75419 |
11.06 |
| 2026-02-12 12:00 |
15:23:57.00 |
-11:02:47.4 |
HIP 75419 |
8.69 |
| 2026-02-13 00:00 |
15:24:06.42 |
-11:03:17.7 |
HIP 75419 |
6.44 |
| 2026-02-13 12:00 |
15:24:15.58 |
-11:03:46.9 |
HIP 75419 |
4.37 |
| 2026-02-14 00:00 |
15:24:24.47 |
-11:04:15.2 |
HIP 75419 |
2.74 |
| 2026-02-14 12:00 |
15:24:33.10 |
-11:04:42.4 |
HIP 75419 |
2.40 |
| 2026-02-15 00:00 |
15:24:41.47 |
-11:05:08.6 |
HIP 75419 |
3.61 |
| 2026-02-15 12:00 |
15:24:49.56 |
-11:05:33.8 |
HIP 75419 |
5.33 |
| 2026-02-16 00:00 |
15:24:57.39 |
-11:05:58.0 |
HIP 75419 |
7.14 |
| 2026-02-16 12:00 |
15:25:04.94 |
-11:06:21.2 |
HIP 75487 |
7.25 |
| 2026-02-17 00:00 |
15:25:12.23 |
-11:06:43.4 |
HIP 75487 |
7.33 |
| 2026-02-17 12:00 |
15:25:19.24 |
-11:07:04.6 |
HIP 75487 |
7.81 |
| 2026-02-18 00:00 |
15:25:25.99 |
-11:07:24.8 |
HIP 75487 |
8.59 |
| 2026-02-18 12:00 |
15:25:32.46 |
-11:07:44.0 |
HIP 75487 |
9.56 |
| 2026-02-19 00:00 |
15:25:38.66 |
-11:08:02.2 |
HIP 75487 |
10.63 |
| 2026-02-19 12:00 |
15:25:44.58 |
-11:08:19.4 |
HIP 75487 |
11.76 |
| 2026-02-20 00:00 |
15:25:50.23 |
-11:08:35.7 |
HIP 75487 |
12.90 |
| 2026-02-20 12:00 |
15:25:55.60 |
-11:08:51.0 |
HIP 75487 |
14.02 |
| 2026-02-21 00:00 |
15:26:00.70 |
-11:09:05.3 |
HIP 75487 |
15.12 |
| 2026-02-21 12:00 |
15:26:05.52 |
-11:09:18.7 |
HIP 75487 |
16.19 |
| 2026-02-22 00:00 |
15:26:10.06 |
-11:09:31.1 |
HIP 75487 |
17.20 |
| 2026-02-22 12:00 |
15:26:14.32 |
-11:09:42.5 |
HIP 75487 |
18.17 |
| 2026-02-23 00:00 |
15:26:18.31 |
-11:09:53.1 |
HIP 75487 |
19.08 |
| 2026-02-23 12:00 |
15:26:22.02 |
-11:10:02.6 |
HIP 75487 |
19.93 |
| 2026-02-24 00:00 |
15:26:25.45 |
-11:10:11.3 |
HIP 75663 |
20.20 |