| Parameter |
Value |
| Designation |
195P/Hill |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2025-07-30T04:43:18.353280Z |
| Orbit solution date (soln_date, UTC) |
2026-05-22T14:12:31Z |
| Obs used |
1248 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
12.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-02-11.0000000 |
| e |
0.31337309 |
| q (au) |
4.460833 |
| a (au) |
6.496735 |
| i (deg) |
36.341875 |
| Ω (om, deg) |
243.094859 |
| ω (w, deg) |
249.522545 |
| M (ma, deg) |
241.186808 |
Magnitude
Scatter + Global Linear
$$
M_a = (4.225 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
4.225 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
| 2021-09-13 |
2022-11-27 |
-11.4196 |
+9.278 |
| 2022-11-27 |
2023-10-30 |
-4.4495 |
+3.723 |
| 2023-10-30 |
2025-05-13 |
+7.4071 |
-5.072 |
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 |
09:40:04.30 |
-23:51:23.4 |
HIP 47365 |
16.67 |
| 2026-06-01 12:00 |
09:40:25.85 |
-23:49:22.4 |
HIP 47522 |
18.16 |
| 2026-06-02 00:00 |
09:40:47.54 |
-23:47:22.9 |
HIP 47522 |
13.67 |
| 2026-06-02 12:00 |
09:41:09.37 |
-23:45:24.9 |
HIP 47522 |
10.08 |
| 2026-06-03 00:00 |
09:41:31.32 |
-23:43:28.5 |
HIP 47522 |
8.63 |
| 2026-06-03 12:00 |
09:41:53.41 |
-23:41:33.6 |
HIP 47522 |
10.31 |
| 2026-06-04 00:00 |
09:42:15.64 |
-23:39:40.2 |
HIP 47522 |
14.06 |
| 2026-06-04 12:00 |
09:42:37.99 |
-23:37:48.4 |
HIP 47592 |
17.98 |
| 2026-06-05 00:00 |
09:43:00.47 |
-23:35:58.2 |
HIP 47592 |
21.70 |
| 2026-06-05 12:00 |
09:43:23.09 |
-23:34:09.5 |
HIP 47798 |
17.46 |
| 2026-06-06 00:00 |
09:43:45.83 |
-23:32:22.3 |
HIP 47798 |
12.41 |
| 2026-06-06 12:00 |
09:44:08.70 |
-23:30:36.7 |
HIP 47798 |
7.95 |
| 2026-06-07 00:00 |
09:44:31.69 |
-23:28:52.6 |
HIP 47828 |
5.61 |
| 2026-06-07 12:00 |
09:44:54.81 |
-23:27:10.1 |
HIP 47828 |
1.92 |
| 2026-06-08 00:00 |
09:45:18.05 |
-23:25:29.2 |
HIP 47828 |
6.17 |
| 2026-06-08 12:00 |
09:45:41.42 |
-23:23:49.8 |
HIP 47828 |
11.63 |
| 2026-06-09 00:00 |
09:46:04.91 |
-23:22:12.0 |
HIP 47828 |
17.21 |
| 2026-06-09 12:00 |
09:46:28.52 |
-23:20:35.7 |
HIP 47828 |
22.82 |
| 2026-06-10 00:00 |
09:46:52.25 |
-23:19:01.0 |
HIP 47828 |
28.47 |
| 2026-06-10 12:00 |
09:47:16.10 |
-23:17:27.8 |
HIP 48096 |
31.75 |
| 2026-06-11 00:00 |
09:47:40.07 |
-23:15:56.2 |
HIP 48096 |
28.05 |
| 2026-06-11 12:00 |
09:48:04.16 |
-23:14:26.2 |
HIP 48096 |
25.13 |
| 2026-06-12 00:00 |
09:48:28.36 |
-23:12:57.8 |
HIP 48096 |
23.32 |
| 2026-06-12 12:00 |
09:48:52.68 |
-23:11:30.9 |
HIP 48096 |
22.88 |
| 2026-06-13 00:00 |
09:49:17.12 |
-23:10:05.6 |
HIP 48096 |
23.92 |
| 2026-06-13 12:00 |
09:49:41.67 |
-23:08:41.8 |
HIP 48327 |
20.36 |
| 2026-06-14 00:00 |
09:50:06.33 |
-23:07:19.6 |
HIP 48327 |
14.62 |
| 2026-06-14 12:00 |
09:50:31.10 |
-23:05:59.0 |
HIP 48327 |
8.98 |
| 2026-06-15 00:00 |
09:50:55.99 |
-23:04:40.0 |
HIP 48327 |
4.04 |
| 2026-06-15 12:00 |
09:51:20.98 |
-23:03:22.6 |
HIP 48327 |
4.61 |
| 2026-06-16 00:00 |
09:51:46.08 |
-23:02:06.7 |
HIP 48327 |
9.81 |
| 2026-06-16 12:00 |
09:52:11.29 |
-23:00:52.4 |
HIP 48327 |
15.55 |
| 2026-06-17 00:00 |
09:52:36.61 |
-22:59:39.7 |
HIP 48516 |
17.29 |
| 2026-06-17 12:00 |
09:53:02.03 |
-22:58:28.5 |
HIP 48516 |
11.96 |
| 2026-06-18 00:00 |
09:53:27.55 |
-22:57:18.9 |
HIP 48516 |
7.67 |
| 2026-06-18 12:00 |
09:53:53.18 |
-22:56:10.9 |
HIP 48516 |
6.84 |
| 2026-06-19 00:00 |
09:54:18.91 |
-22:55:04.4 |
HIP 48516 |
10.38 |
| 2026-06-19 12:00 |
09:54:44.74 |
-22:53:59.5 |
HIP 48516 |
15.57 |
| 2026-06-20 00:00 |
09:55:10.67 |
-22:52:56.2 |
HIP 48516 |
21.25 |
| 2026-06-20 12:00 |
09:55:36.70 |
-22:51:54.4 |
HIP 48516 |
27.12 |
| 2026-06-21 00:00 |
09:56:02.83 |
-22:50:54.1 |
HIP 48826 |
22.11 |
| 2026-06-21 12:00 |
09:56:29.05 |
-22:49:55.5 |
HIP 48826 |
16.46 |
| 2026-06-22 00:00 |
09:56:55.37 |
-22:48:58.3 |
HIP 48826 |
11.28 |