| Parameter |
Value |
| Designation |
385P/Hill |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2010-11-09T10:11:43.048320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:41Z |
| Obs used |
353 |
| NEO |
- |
| M1 |
7.400 |
| K1 |
25.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2019-08-02T01:14:10.464000Z |
| Discovery magnitude (MPC) |
20.40 T |
| Discovery observatory (MPC) |
461 · University of Szeged, Piszkéstető Stn. (Konkoly) |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-11-22.0000000 |
| e |
0.40226883 |
| q (au) |
2.555233 |
| a (au) |
4.274887 |
| i (deg) |
16.855651 |
| Ω (om, deg) |
357.157345 |
| ω (w, deg) |
44.328792 |
| M (ma, deg) |
82.916702 |
Magnitude
Scatter + Global Linear
$$
M_a = (18.057 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
18.057 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.644 |
| k |
0.800 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
18:33:04.75 |
-43:53:47.6 |
HIP 90782 |
19.75 |
| 2026-06-01 12:00 |
18:32:45.36 |
-43:55:04.8 |
HIP 90782 |
16.59 |
| 2026-06-02 00:00 |
18:32:25.77 |
-43:56:20.8 |
HIP 90782 |
13.68 |
| 2026-06-02 12:00 |
18:32:05.96 |
-43:57:35.8 |
HIP 90782 |
11.25 |
| 2026-06-03 00:00 |
18:31:45.95 |
-43:58:49.6 |
HIP 90782 |
9.68 |
| 2026-06-03 12:00 |
18:31:25.73 |
-44:00:02.3 |
HIP 90782 |
9.45 |
| 2026-06-04 00:00 |
18:31:05.31 |
-44:01:13.8 |
HIP 90782 |
10.69 |
| 2026-06-04 12:00 |
18:30:44.70 |
-44:02:24.1 |
HIP 90782 |
13.00 |
| 2026-06-05 00:00 |
18:30:23.88 |
-44:03:33.2 |
HIP 90674 |
13.99 |
| 2026-06-05 12:00 |
18:30:02.88 |
-44:04:41.0 |
HIP 90563 |
13.69 |
| 2026-06-06 00:00 |
18:29:41.69 |
-44:05:47.6 |
HIP 90563 |
9.88 |
| 2026-06-06 12:00 |
18:29:20.31 |
-44:06:53.0 |
HIP 90563 |
6.23 |
| 2026-06-07 00:00 |
18:28:58.75 |
-44:07:57.0 |
HIP 90563 |
3.41 |
| 2026-06-07 12:00 |
18:28:37.01 |
-44:08:59.7 |
HIP 90563 |
4.08 |
| 2026-06-08 00:00 |
18:28:15.09 |
-44:10:01.2 |
HIP 90563 |
7.38 |
| 2026-06-08 12:00 |
18:27:53.00 |
-44:11:01.2 |
HIP 90563 |
11.21 |
| 2026-06-09 00:00 |
18:27:30.74 |
-44:12:00.0 |
HIP 90563 |
15.19 |
| 2026-06-09 12:00 |
18:27:08.32 |
-44:12:57.3 |
HIP 90323 |
16.24 |
| 2026-06-10 00:00 |
18:26:45.74 |
-44:13:53.3 |
HIP 90323 |
13.16 |
| 2026-06-10 12:00 |
18:26:22.99 |
-44:14:47.8 |
HIP 90323 |
10.80 |
| 2026-06-11 00:00 |
18:26:00.10 |
-44:15:41.0 |
HIP 90323 |
9.72 |
| 2026-06-11 12:00 |
18:25:37.05 |
-44:16:32.7 |
HIP 90323 |
10.35 |
| 2026-06-12 00:00 |
18:25:13.86 |
-44:17:22.9 |
HIP 90323 |
12.45 |
| 2026-06-12 12:00 |
18:24:50.52 |
-44:18:11.6 |
HIP 90200 |
12.95 |
| 2026-06-13 00:00 |
18:24:27.05 |
-44:18:58.9 |
HIP 90200 |
12.47 |
| 2026-06-13 12:00 |
18:24:03.44 |
-44:19:44.7 |
HIP 90200 |
13.40 |
| 2026-06-14 00:00 |
18:23:39.71 |
-44:20:28.9 |
HIP 90200 |
15.49 |
| 2026-06-14 12:00 |
18:23:15.85 |
-44:21:11.6 |
HIP 90200 |
18.37 |
| 2026-06-15 00:00 |
18:22:51.87 |
-44:21:52.8 |
HIP 90200 |
21.74 |
| 2026-06-15 12:00 |
18:22:27.78 |
-44:22:32.4 |
HIP 90200 |
25.40 |
| 2026-06-16 00:00 |
18:22:03.57 |
-44:23:10.5 |
HIP 89887 |
25.20 |
| 2026-06-16 12:00 |
18:21:39.26 |
-44:23:46.9 |
HIP 89887 |
22.99 |
| 2026-06-17 00:00 |
18:21:14.85 |
-44:24:21.8 |
HIP 89887 |
21.43 |
| 2026-06-17 12:00 |
18:20:50.34 |
-44:24:55.0 |
HIP 89887 |
20.68 |
| 2026-06-18 00:00 |
18:20:25.74 |
-44:25:26.7 |
HIP 89887 |
20.84 |
| 2026-06-18 12:00 |
18:20:01.05 |
-44:25:56.7 |
HIP 89887 |
21.89 |
| 2026-06-19 00:00 |
18:19:36.28 |
-44:26:25.0 |
HIP 89638 |
22.42 |
| 2026-06-19 12:00 |
18:19:11.43 |
-44:26:51.8 |
HIP 89638 |
18.08 |
| 2026-06-20 00:00 |
18:18:46.51 |
-44:27:16.8 |
HIP 89638 |
13.82 |
| 2026-06-20 12:00 |
18:18:21.52 |
-44:27:40.2 |
HIP 89638 |
9.76 |
| 2026-06-21 00:00 |
18:17:56.47 |
-44:28:02.0 |
HIP 89638 |
6.28 |
| 2026-06-21 12:00 |
18:17:31.36 |
-44:28:22.0 |
HIP 89638 |
4.92 |
| 2026-06-22 00:00 |
18:17:06.20 |
-44:28:40.4 |
HIP 89638 |
7.05 |