| Parameter |
Value |
| Designation |
C/2009 U5 (Grauer) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2010-06-22T11:50:14.052480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:37Z |
| Obs used |
182 |
| NEO |
- |
| M1 |
11.800 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2010-02-02.0000000 |
| e |
0.99942402 |
| q (au) |
6.094240 |
| a (au) |
10580.667509 |
| i (deg) |
25.472676 |
| Ω (om, deg) |
121.174091 |
| ω (w, deg) |
23.813513 |
| M (ma, deg) |
359.999873 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.379 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.379 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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 |
18:14:19.66 |
-11:05:38.5 |
HIP 89377 |
24.94 |
| 2026-07-29 12:00 |
18:14:16.79 |
-11:05:48.8 |
HIP 89377 |
25.14 |
| 2026-07-30 00:00 |
18:14:13.93 |
-11:05:59.2 |
HIP 89377 |
25.36 |
| 2026-07-30 12:00 |
18:14:11.10 |
-11:06:09.7 |
HIP 89377 |
25.61 |
| 2026-07-31 00:00 |
18:14:08.29 |
-11:06:20.3 |
HIP 89377 |
25.87 |
| 2026-07-31 12:00 |
18:14:05.49 |
-11:06:31.0 |
HIP 89377 |
26.14 |
| 2026-08-01 00:00 |
18:14:02.72 |
-11:06:41.7 |
HIP 89377 |
26.44 |
| 2026-08-01 12:00 |
18:13:59.96 |
-11:06:52.5 |
HIP 89377 |
26.75 |
| 2026-08-02 00:00 |
18:13:57.23 |
-11:07:03.3 |
HIP 89377 |
27.07 |
| 2026-08-02 12:00 |
18:13:54.51 |
-11:07:14.3 |
HIP 89377 |
27.41 |
| 2026-08-03 00:00 |
18:13:51.82 |
-11:07:25.3 |
HIP 89377 |
27.76 |
| 2026-08-03 12:00 |
18:13:49.15 |
-11:07:36.4 |
HIP 89377 |
28.13 |
| 2026-08-04 00:00 |
18:13:46.50 |
-11:07:47.5 |
HIP 89377 |
28.50 |
| 2026-08-04 12:00 |
18:13:43.87 |
-11:07:58.7 |
HIP 89377 |
28.88 |
| 2026-08-05 00:00 |
18:13:41.26 |
-11:08:10.0 |
HIP 89377 |
29.28 |
| 2026-08-05 12:00 |
18:13:38.68 |
-11:08:21.4 |
HIP 89377 |
29.68 |
| 2026-08-06 00:00 |
18:13:36.12 |
-11:08:32.8 |
HIP 89377 |
30.09 |
| 2026-08-06 12:00 |
18:13:33.58 |
-11:08:44.3 |
HIP 89218 |
30.06 |
| 2026-08-07 00:00 |
18:13:31.06 |
-11:08:55.8 |
HIP 89218 |
29.88 |
| 2026-08-07 12:00 |
18:13:28.57 |
-11:09:07.4 |
HIP 89218 |
29.72 |
| 2026-08-08 00:00 |
18:13:26.10 |
-11:09:19.1 |
HIP 89218 |
29.57 |
| 2026-08-08 12:00 |
18:13:23.65 |
-11:09:30.9 |
HIP 89218 |
29.44 |
| 2026-08-09 00:00 |
18:13:21.22 |
-11:09:42.7 |
HIP 89136 |
29.12 |
| 2026-08-09 12:00 |
18:13:18.82 |
-11:09:54.5 |
HIP 89136 |
28.50 |
| 2026-08-10 00:00 |
18:13:16.45 |
-11:10:06.5 |
HIP 89136 |
27.89 |
| 2026-08-10 12:00 |
18:13:14.10 |
-11:10:18.4 |
HIP 89136 |
27.28 |
| 2026-08-11 00:00 |
18:13:11.77 |
-11:10:30.5 |
HIP 89136 |
26.67 |
| 2026-08-11 12:00 |
18:13:09.47 |
-11:10:42.6 |
HIP 89136 |
26.07 |
| 2026-08-12 00:00 |
18:13:07.19 |
-11:10:54.8 |
HIP 89136 |
25.48 |
| 2026-08-12 12:00 |
18:13:04.94 |
-11:11:07.0 |
HIP 89136 |
24.89 |
| 2026-08-13 00:00 |
18:13:02.71 |
-11:11:19.3 |
HIP 89136 |
24.31 |
| 2026-08-13 12:00 |
18:13:00.51 |
-11:11:31.6 |
HIP 89136 |
23.73 |
| 2026-08-14 00:00 |
18:12:58.34 |
-11:11:44.0 |
HIP 89136 |
23.16 |
| 2026-08-14 12:00 |
18:12:56.19 |
-11:11:56.5 |
HIP 89136 |
22.60 |
| 2026-08-15 00:00 |
18:12:54.06 |
-11:12:09.0 |
HIP 89136 |
22.04 |
| 2026-08-15 12:00 |
18:12:51.97 |
-11:12:21.5 |
HIP 89136 |
21.49 |
| 2026-08-16 00:00 |
18:12:49.90 |
-11:12:34.1 |
HIP 89136 |
20.94 |
| 2026-08-16 12:00 |
18:12:47.85 |
-11:12:46.8 |
HIP 89136 |
20.40 |
| 2026-08-17 00:00 |
18:12:45.84 |
-11:12:59.5 |
HIP 89136 |
19.86 |
| 2026-08-17 12:00 |
18:12:43.85 |
-11:13:12.2 |
HIP 89136 |
19.34 |
| 2026-08-18 00:00 |
18:12:41.89 |
-11:13:25.0 |
HIP 89136 |
18.82 |
| 2026-08-18 12:00 |
18:12:39.95 |
-11:13:37.9 |
HIP 89136 |
18.30 |
| 2026-08-19 00:00 |
18:12:38.04 |
-11:13:50.8 |
HIP 89136 |
17.79 |