211P/Hill
| 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) |
| 2026-02-03 00:00 |
20:22:39.42 |
-20:31:08.4 |
HIP 100478 |
7.11 |
| 2026-02-03 12:00 |
20:23:08.91 |
-20:30:08.7 |
HIP 100563 |
5.24 |
| 2026-02-04 00:00 |
20:23:38.38 |
-20:29:08.7 |
HIP 100563 |
3.25 |
| 2026-02-04 12:00 |
20:24:07.82 |
-20:28:08.6 |
HIP 100563 |
9.53 |
| 2026-02-05 00:00 |
20:24:37.24 |
-20:27:08.3 |
HIP 100563 |
16.38 |
| 2026-02-05 12:00 |
20:25:06.62 |
-20:26:07.9 |
HIP 100563 |
23.28 |
| 2026-02-06 00:00 |
20:25:35.98 |
-20:25:07.3 |
HIP 100563 |
30.21 |
| 2026-02-06 12:00 |
20:26:05.31 |
-20:24:06.6 |
HIP 100950 |
28.46 |
| 2026-02-07 00:00 |
20:26:34.61 |
-20:23:05.7 |
HIP 100950 |
21.54 |
| 2026-02-07 12:00 |
20:27:03.88 |
-20:22:04.6 |
HIP 100950 |
14.63 |
| 2026-02-08 00:00 |
20:27:33.12 |
-20:21:03.5 |
HIP 100950 |
7.79 |
| 2026-02-08 12:00 |
20:28:02.33 |
-20:20:02.1 |
HIP 100950 |
1.80 |
| 2026-02-09 00:00 |
20:28:31.50 |
-20:19:00.7 |
HIP 100950 |
6.45 |
| 2026-02-09 12:00 |
20:29:00.64 |
-20:17:59.2 |
HIP 100950 |
13.24 |
| 2026-02-10 00:00 |
20:29:29.75 |
-20:16:57.5 |
HIP 100950 |
20.11 |
| 2026-02-10 12:00 |
20:29:58.82 |
-20:15:55.7 |
HIP 100950 |
26.99 |
| 2026-02-11 00:00 |
20:30:27.86 |
-20:14:53.8 |
HIP 101192 |
27.85 |
| 2026-02-11 12:00 |
20:30:56.86 |
-20:13:51.8 |
HIP 101374 |
27.61 |
| 2026-02-12 00:00 |
20:31:25.82 |
-20:12:49.7 |
HIP 101374 |
20.93 |
| 2026-02-12 12:00 |
20:31:54.75 |
-20:11:47.5 |
HIP 101374 |
14.44 |
| 2026-02-13 00:00 |
20:32:23.64 |
-20:10:45.2 |
HIP 101374 |
8.57 |
| 2026-02-13 12:00 |
20:32:52.48 |
-20:09:42.8 |
HIP 101374 |
5.69 |
| 2026-02-14 00:00 |
20:33:21.29 |
-20:08:40.4 |
HIP 101374 |
9.22 |
| 2026-02-14 12:00 |
20:33:50.06 |
-20:07:37.9 |
HIP 101374 |
15.20 |
| 2026-02-15 00:00 |
20:34:18.79 |
-20:06:35.3 |
HIP 101374 |
21.68 |
| 2026-02-15 12:00 |
20:34:47.47 |
-20:05:32.7 |
HIP 101374 |
28.32 |
| 2026-02-16 00:00 |
20:35:16.11 |
-20:04:30.0 |
HIP 101666 |
34.79 |
| 2026-02-16 12:00 |
20:35:44.71 |
-20:03:27.2 |
HIP 101666 |
33.15 |
| 2026-02-17 00:00 |
20:36:13.26 |
-20:02:24.4 |
HIP 101666 |
32.87 |
| 2026-02-17 12:00 |
20:36:41.77 |
-20:01:21.6 |
HIP 101666 |
33.96 |
| 2026-02-18 00:00 |
20:37:10.23 |
-20:00:18.8 |
HIP 101840 |
30.94 |
| 2026-02-18 12:00 |
20:37:38.64 |
-19:59:15.9 |
HIP 101840 |
27.16 |
| 2026-02-19 00:00 |
20:38:07.01 |
-19:58:13.0 |
HIP 101952 |
22.14 |
| 2026-02-19 12:00 |
20:38:35.33 |
-19:57:10.1 |
HIP 101952 |
16.49 |
| 2026-02-20 00:00 |
20:39:03.59 |
-19:56:07.1 |
HIP 101952 |
12.02 |
| 2026-02-20 12:00 |
20:39:31.81 |
-19:55:04.2 |
HIP 101952 |
10.36 |
| 2026-02-21 00:00 |
20:39:59.98 |
-19:54:01.3 |
HIP 101952 |
12.65 |
| 2026-02-21 12:00 |
20:40:28.10 |
-19:52:58.4 |
HIP 101952 |
17.39 |
| 2026-02-22 00:00 |
20:40:56.16 |
-19:51:55.5 |
HIP 101952 |
23.10 |
| 2026-02-22 12:00 |
20:41:24.17 |
-19:50:52.6 |
HIP 102207 |
21.48 |
| 2026-02-23 00:00 |
20:41:52.13 |
-19:49:49.8 |
HIP 102225 |
17.16 |
| 2026-02-23 12:00 |
20:42:20.03 |
-19:48:47.0 |
HIP 102225 |
13.66 |
| 2026-02-24 00:00 |
20:42:47.87 |
-19:47:44.2 |
HIP 102225 |
12.92 |