| Parameter |
Value |
| Designation |
420P/Hill |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2009-06-29T08:33:30.939840Z |
| Orbit solution date (soln_date, UTC) |
2024-05-30T01:12:43Z |
| Obs used |
223 |
| NEO |
- |
| M1 |
15.400 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-08-01.0000000 |
| e |
0.49432464 |
| q (au) |
2.787876 |
| a (au) |
5.513174 |
| i (deg) |
14.459998 |
| Ω (om, deg) |
174.032327 |
| ω (w, deg) |
157.611202 |
| M (ma, deg) |
141.513392 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.775 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.775 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.856 |
| k |
0.999 |
| 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) |
| 2026-06-01 00:00 |
07:48:24.35 |
+10:33:36.7 |
HIP 38153 |
18.07 |
| 2026-06-01 12:00 |
07:48:38.90 |
+10:33:34.3 |
HIP 38153 |
16.31 |
| 2026-06-02 00:00 |
07:48:53.51 |
+10:33:31.3 |
HIP 38153 |
15.19 |
| 2026-06-02 12:00 |
07:49:08.18 |
+10:33:27.9 |
HIP 38153 |
14.89 |
| 2026-06-03 00:00 |
07:49:22.91 |
+10:33:23.9 |
HIP 38263 |
14.76 |
| 2026-06-03 12:00 |
07:49:37.70 |
+10:33:19.4 |
HIP 38263 |
11.20 |
| 2026-06-04 00:00 |
07:49:52.54 |
+10:33:14.5 |
HIP 38263 |
7.71 |
| 2026-06-04 12:00 |
07:50:07.45 |
+10:33:09.0 |
HIP 38263 |
4.47 |
| 2026-06-05 00:00 |
07:50:22.41 |
+10:33:03.0 |
HIP 38263 |
2.69 |
| 2026-06-05 12:00 |
07:50:37.43 |
+10:32:56.5 |
HIP 38263 |
4.65 |
| 2026-06-06 00:00 |
07:50:52.51 |
+10:32:49.5 |
HIP 38263 |
7.97 |
| 2026-06-06 12:00 |
07:51:07.64 |
+10:32:42.0 |
HIP 38263 |
11.54 |
| 2026-06-07 00:00 |
07:51:22.83 |
+10:32:34.1 |
HIP 38263 |
15.19 |
| 2026-06-07 12:00 |
07:51:38.07 |
+10:32:25.6 |
HIP 38263 |
18.89 |
| 2026-06-08 00:00 |
07:51:53.36 |
+10:32:16.6 |
HIP 38263 |
22.62 |
| 2026-06-08 12:00 |
07:52:08.71 |
+10:32:07.1 |
HIP 38547 |
23.53 |
| 2026-06-09 00:00 |
07:52:24.11 |
+10:31:57.1 |
HIP 38547 |
20.17 |
| 2026-06-09 12:00 |
07:52:39.56 |
+10:31:46.6 |
HIP 38547 |
16.99 |
| 2026-06-10 00:00 |
07:52:55.07 |
+10:31:35.7 |
HIP 38547 |
14.11 |
| 2026-06-10 12:00 |
07:53:10.62 |
+10:31:24.2 |
HIP 38547 |
11.77 |
| 2026-06-11 00:00 |
07:53:26.23 |
+10:31:12.2 |
HIP 38547 |
10.37 |
| 2026-06-11 12:00 |
07:53:41.88 |
+10:30:59.7 |
HIP 38547 |
10.30 |
| 2026-06-12 00:00 |
07:53:57.58 |
+10:30:46.8 |
HIP 38547 |
11.61 |
| 2026-06-12 12:00 |
07:54:13.34 |
+10:30:33.3 |
HIP 38547 |
13.91 |
| 2026-06-13 00:00 |
07:54:29.13 |
+10:30:19.4 |
HIP 38672 |
11.18 |
| 2026-06-13 12:00 |
07:54:44.98 |
+10:30:04.9 |
HIP 38672 |
8.39 |
| 2026-06-14 00:00 |
07:55:00.87 |
+10:29:50.0 |
HIP 38672 |
6.79 |
| 2026-06-14 12:00 |
07:55:16.81 |
+10:29:34.6 |
HIP 38672 |
7.24 |
| 2026-06-15 00:00 |
07:55:32.79 |
+10:29:18.6 |
HIP 38734 |
4.55 |
| 2026-06-15 12:00 |
07:55:48.81 |
+10:29:02.2 |
HIP 38734 |
2.45 |
| 2026-06-16 00:00 |
07:56:04.88 |
+10:28:45.3 |
HIP 38734 |
4.75 |
| 2026-06-16 12:00 |
07:56:20.99 |
+10:28:28.0 |
HIP 38734 |
8.40 |
| 2026-06-17 00:00 |
07:56:37.14 |
+10:28:10.1 |
HIP 38734 |
12.27 |
| 2026-06-17 12:00 |
07:56:53.34 |
+10:27:51.7 |
HIP 38734 |
16.20 |
| 2026-06-18 00:00 |
07:57:09.57 |
+10:27:32.9 |
HIP 38734 |
20.16 |
| 2026-06-18 12:00 |
07:57:25.84 |
+10:27:13.6 |
HIP 38734 |
24.15 |
| 2026-06-19 00:00 |
07:57:42.15 |
+10:26:53.8 |
HIP 38992 |
25.39 |
| 2026-06-19 12:00 |
07:57:58.50 |
+10:26:33.6 |
HIP 38992 |
22.67 |
| 2026-06-20 00:00 |
07:58:14.89 |
+10:26:12.8 |
HIP 38992 |
20.37 |
| 2026-06-20 12:00 |
07:58:31.31 |
+10:25:51.6 |
HIP 38992 |
18.66 |
| 2026-06-21 00:00 |
07:58:47.77 |
+10:25:29.9 |
HIP 38992 |
17.73 |
| 2026-06-21 12:00 |
07:59:04.26 |
+10:25:07.8 |
HIP 38992 |
17.69 |
| 2026-06-22 00:00 |
07:59:20.79 |
+10:24:45.2 |
HIP 38992 |
18.57 |