| 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) |
| 2026-07-29 00:00 |
21:23:27.11 |
-22:49:41.0 |
HIP 105662 |
10.59 |
| 2026-07-29 12:00 |
21:23:08.51 |
-22:52:14.2 |
HIP 105576 |
12.23 |
| 2026-07-30 00:00 |
21:22:49.81 |
-22:54:47.1 |
HIP 105576 |
14.85 |
| 2026-07-30 12:00 |
21:22:31.03 |
-22:57:19.7 |
HIP 105576 |
18.48 |
| 2026-07-31 00:00 |
21:22:12.18 |
-22:59:52.0 |
HIP 105576 |
22.65 |
| 2026-07-31 12:00 |
21:21:53.24 |
-23:02:24.0 |
HIP 105576 |
27.12 |
| 2026-08-01 00:00 |
21:21:34.23 |
-23:04:55.7 |
HIP 105576 |
31.76 |
| 2026-08-01 12:00 |
21:21:15.16 |
-23:07:27.0 |
HIP 105368 |
30.54 |
| 2026-08-02 00:00 |
21:20:56.01 |
-23:09:57.9 |
HIP 105368 |
26.96 |
| 2026-08-02 12:00 |
21:20:36.80 |
-23:12:28.5 |
HIP 105368 |
23.94 |
| 2026-08-03 00:00 |
21:20:17.53 |
-23:14:58.6 |
HIP 105368 |
21.69 |
| 2026-08-03 12:00 |
21:19:58.20 |
-23:17:28.3 |
HIP 105368 |
20.51 |
| 2026-08-04 00:00 |
21:19:38.81 |
-23:19:57.6 |
HIP 105368 |
20.56 |
| 2026-08-04 12:00 |
21:19:19.37 |
-23:22:26.3 |
HIP 105368 |
21.84 |
| 2026-08-05 00:00 |
21:18:59.89 |
-23:24:54.6 |
HIP 105284 |
22.61 |
| 2026-08-05 12:00 |
21:18:40.36 |
-23:27:22.4 |
HIP 105217 |
21.12 |
| 2026-08-06 00:00 |
21:18:20.79 |
-23:29:49.6 |
HIP 105217 |
19.43 |
| 2026-08-06 12:00 |
21:18:01.18 |
-23:32:16.2 |
HIP 105217 |
19.01 |
| 2026-08-07 00:00 |
21:17:41.53 |
-23:34:42.3 |
HIP 105217 |
19.95 |
| 2026-08-07 12:00 |
21:17:21.86 |
-23:37:07.8 |
HIP 105217 |
22.08 |
| 2026-08-08 00:00 |
21:17:02.15 |
-23:39:32.6 |
HIP 105217 |
25.10 |
| 2026-08-08 12:00 |
21:16:42.43 |
-23:41:56.8 |
HIP 105217 |
28.72 |
| 2026-08-09 00:00 |
21:16:22.68 |
-23:44:20.4 |
HIP 105217 |
32.74 |
| 2026-08-09 12:00 |
21:16:02.91 |
-23:46:43.3 |
HIP 104827 |
34.36 |
| 2026-08-10 00:00 |
21:15:43.14 |
-23:49:05.4 |
HIP 104827 |
29.45 |
| 2026-08-10 12:00 |
21:15:23.35 |
-23:51:26.9 |
HIP 104827 |
24.64 |
| 2026-08-11 00:00 |
21:15:03.56 |
-23:53:47.6 |
HIP 104827 |
19.98 |
| 2026-08-11 12:00 |
21:14:43.76 |
-23:56:07.5 |
HIP 104827 |
15.60 |
| 2026-08-12 00:00 |
21:14:23.97 |
-23:58:26.7 |
HIP 104827 |
11.82 |
| 2026-08-12 12:00 |
21:14:04.18 |
-24:00:45.0 |
HIP 104827 |
9.38 |
| 2026-08-13 00:00 |
21:13:44.41 |
-24:03:02.6 |
HIP 104827 |
9.37 |
| 2026-08-13 12:00 |
21:13:24.64 |
-24:05:19.3 |
HIP 104827 |
11.78 |
| 2026-08-14 00:00 |
21:13:04.90 |
-24:07:35.1 |
HIP 104664 |
14.20 |
| 2026-08-14 12:00 |
21:12:45.17 |
-24:09:50.1 |
HIP 104664 |
10.03 |
| 2026-08-15 00:00 |
21:12:25.47 |
-24:12:04.2 |
HIP 104664 |
7.07 |
| 2026-08-15 12:00 |
21:12:05.80 |
-24:14:17.4 |
HIP 104664 |
7.04 |
| 2026-08-16 00:00 |
21:11:46.16 |
-24:16:29.6 |
HIP 104664 |
9.94 |
| 2026-08-16 12:00 |
21:11:26.56 |
-24:18:40.9 |
HIP 104664 |
14.06 |
| 2026-08-17 00:00 |
21:11:07.00 |
-24:20:51.3 |
HIP 104476 |
17.47 |
| 2026-08-17 12:00 |
21:10:47.48 |
-24:23:00.6 |
HIP 104476 |
12.77 |
| 2026-08-18 00:00 |
21:10:28.01 |
-24:25:09.0 |
HIP 104476 |
8.37 |
| 2026-08-18 12:00 |
21:10:08.58 |
-24:27:16.4 |
HIP 104476 |
5.04 |
| 2026-08-19 00:00 |
21:09:49.22 |
-24:29:22.8 |
HIP 104476 |
5.36 |