| Parameter |
Value |
| Designation |
211P/Hill |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2016-01-27T02:47:26.427840Z |
| Orbit solution date (soln_date, UTC) |
2024-05-14T12:42:30Z |
| Obs used |
854 |
| NEO |
- |
| M1 |
7.800 |
| K1 |
24.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-03-20.0000000 |
| e |
0.33923044 |
| q (au) |
2.351929 |
| a (au) |
3.559379 |
| i (deg) |
18.888227 |
| Ω (om, deg) |
117.272120 |
| ω (w, deg) |
4.337626 |
| M (ma, deg) |
260.471637 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.022 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.022 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-0.818 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
21:36:02.49 |
-18:19:37.6 |
HIP 106673 |
6.10 |
| 2026-05-12 12:00 |
21:36:12.99 |
-18:19:59.4 |
HIP 106673 |
4.16 |
| 2026-05-13 00:00 |
21:36:23.31 |
-18:20:22.2 |
HIP 106673 |
3.17 |
| 2026-05-13 12:00 |
21:36:33.45 |
-18:20:46.1 |
HIP 106673 |
3.83 |
| 2026-05-14 00:00 |
21:36:43.42 |
-18:21:11.2 |
HIP 106673 |
5.54 |
| 2026-05-14 12:00 |
21:36:53.20 |
-18:21:37.3 |
HIP 106673 |
7.59 |
| 2026-05-15 00:00 |
21:37:02.81 |
-18:22:04.5 |
HIP 106741 |
6.16 |
| 2026-05-15 12:00 |
21:37:12.23 |
-18:22:32.8 |
HIP 106741 |
4.44 |
| 2026-05-16 00:00 |
21:37:21.47 |
-18:23:02.2 |
HIP 106741 |
3.42 |
| 2026-05-16 12:00 |
21:37:30.53 |
-18:23:32.8 |
HIP 106741 |
3.67 |
| 2026-05-17 00:00 |
21:37:39.41 |
-18:24:04.5 |
HIP 106741 |
4.96 |
| 2026-05-17 12:00 |
21:37:48.10 |
-18:24:37.3 |
HIP 106741 |
6.67 |
| 2026-05-18 00:00 |
21:37:56.60 |
-18:25:11.2 |
HIP 106741 |
8.52 |
| 2026-05-18 12:00 |
21:38:04.92 |
-18:25:46.3 |
HIP 106741 |
10.42 |
| 2026-05-19 00:00 |
21:38:13.05 |
-18:26:22.5 |
HIP 106741 |
12.33 |
| 2026-05-19 12:00 |
21:38:20.99 |
-18:26:59.8 |
HIP 106741 |
14.22 |
| 2026-05-20 00:00 |
21:38:28.74 |
-18:27:38.3 |
HIP 106868 |
14.14 |
| 2026-05-20 12:00 |
21:38:36.31 |
-18:28:18.0 |
HIP 106868 |
13.23 |
| 2026-05-21 00:00 |
21:38:43.68 |
-18:28:58.7 |
HIP 106868 |
12.53 |
| 2026-05-21 12:00 |
21:38:50.87 |
-18:29:40.7 |
HIP 106868 |
12.05 |
| 2026-05-22 00:00 |
21:38:57.86 |
-18:30:23.8 |
HIP 106868 |
11.81 |
| 2026-05-22 12:00 |
21:39:04.66 |
-18:31:08.1 |
HIP 106868 |
11.80 |
| 2026-05-23 00:00 |
21:39:11.27 |
-18:31:53.5 |
HIP 106868 |
12.02 |
| 2026-05-23 12:00 |
21:39:17.68 |
-18:32:40.1 |
HIP 106868 |
12.43 |
| 2026-05-24 00:00 |
21:39:23.91 |
-18:33:27.9 |
HIP 106868 |
13.00 |
| 2026-05-24 12:00 |
21:39:29.93 |
-18:34:16.8 |
HIP 106868 |
13.70 |
| 2026-05-25 00:00 |
21:39:35.77 |
-18:35:06.9 |
HIP 106868 |
14.51 |
| 2026-05-25 12:00 |
21:39:41.40 |
-18:35:58.2 |
HIP 106868 |
15.39 |
| 2026-05-26 00:00 |
21:39:46.85 |
-18:36:50.6 |
HIP 106868 |
16.33 |
| 2026-05-26 12:00 |
21:39:52.09 |
-18:37:44.3 |
HIP 106868 |
17.31 |
| 2026-05-27 00:00 |
21:39:57.14 |
-18:38:39.1 |
HIP 107068 |
17.03 |
| 2026-05-27 12:00 |
21:40:01.99 |
-18:39:35.1 |
HIP 107068 |
15.64 |
| 2026-05-28 00:00 |
21:40:06.64 |
-18:40:32.3 |
HIP 107068 |
14.31 |
| 2026-05-28 12:00 |
21:40:11.09 |
-18:41:30.7 |
HIP 107068 |
13.05 |
| 2026-05-29 00:00 |
21:40:15.34 |
-18:42:30.2 |
HIP 107068 |
11.88 |
| 2026-05-29 12:00 |
21:40:19.39 |
-18:43:31.0 |
HIP 107068 |
10.80 |
| 2026-05-30 00:00 |
21:40:23.24 |
-18:44:32.9 |
HIP 107032 |
9.59 |
| 2026-05-30 12:00 |
21:40:26.89 |
-18:45:36.1 |
HIP 107032 |
8.35 |
| 2026-05-31 00:00 |
21:40:30.34 |
-18:46:40.4 |
HIP 107032 |
7.14 |
| 2026-05-31 12:00 |
21:40:33.58 |
-18:47:45.9 |
HIP 107032 |
5.98 |
| 2026-06-01 00:00 |
21:40:36.62 |
-18:48:52.7 |
HIP 107032 |
4.88 |
| 2026-06-01 12:00 |
21:40:39.45 |
-18:50:00.6 |
HIP 107032 |
3.89 |
| 2026-06-02 00:00 |
21:40:42.08 |
-18:51:09.7 |
HIP 107032 |
3.10 |