| 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) |
| 2026-09-20 00:00 |
18:11:38.56 |
-11:28:35.2 |
HIP 89136 |
10.35 |
| 2026-09-20 12:00 |
18:11:38.67 |
-11:28:49.3 |
HIP 89136 |
10.58 |
| 2026-09-21 00:00 |
18:11:38.81 |
-11:29:03.5 |
HIP 89136 |
10.82 |
| 2026-09-21 12:00 |
18:11:38.99 |
-11:29:17.6 |
HIP 89136 |
11.06 |
| 2026-09-22 00:00 |
18:11:39.20 |
-11:29:31.7 |
HIP 89136 |
11.30 |
| 2026-09-22 12:00 |
18:11:39.44 |
-11:29:45.8 |
HIP 89136 |
11.54 |
| 2026-09-23 00:00 |
18:11:39.72 |
-11:29:59.8 |
HIP 89136 |
11.78 |
| 2026-09-23 12:00 |
18:11:40.02 |
-11:30:13.9 |
HIP 89136 |
12.03 |
| 2026-09-24 00:00 |
18:11:40.37 |
-11:30:28.0 |
HIP 89136 |
12.28 |
| 2026-09-24 12:00 |
18:11:40.74 |
-11:30:42.0 |
HIP 89136 |
12.53 |
| 2026-09-25 00:00 |
18:11:41.14 |
-11:30:56.0 |
HIP 89136 |
12.78 |
| 2026-09-25 12:00 |
18:11:41.58 |
-11:31:10.0 |
HIP 89136 |
13.03 |
| 2026-09-26 00:00 |
18:11:42.05 |
-11:31:24.0 |
HIP 89136 |
13.29 |
| 2026-09-26 12:00 |
18:11:42.56 |
-11:31:37.9 |
HIP 89136 |
13.54 |
| 2026-09-27 00:00 |
18:11:43.09 |
-11:31:51.9 |
HIP 89136 |
13.80 |
| 2026-09-27 12:00 |
18:11:43.66 |
-11:32:05.8 |
HIP 89136 |
14.06 |
| 2026-09-28 00:00 |
18:11:44.27 |
-11:32:19.7 |
HIP 89136 |
14.33 |
| 2026-09-28 12:00 |
18:11:44.90 |
-11:32:33.6 |
HIP 89136 |
14.59 |
| 2026-09-29 00:00 |
18:11:45.57 |
-11:32:47.4 |
HIP 89136 |
14.86 |
| 2026-09-29 12:00 |
18:11:46.27 |
-11:33:01.3 |
HIP 89136 |
15.13 |
| 2026-09-30 00:00 |
18:11:47.00 |
-11:33:15.1 |
HIP 89136 |
15.40 |
| 2026-09-30 12:00 |
18:11:47.76 |
-11:33:28.9 |
HIP 89136 |
15.68 |
| 2026-10-01 00:00 |
18:11:48.56 |
-11:33:42.6 |
HIP 89136 |
15.96 |
| 2026-10-01 12:00 |
18:11:49.39 |
-11:33:56.4 |
HIP 89136 |
16.24 |
| 2026-10-02 00:00 |
18:11:50.25 |
-11:34:10.1 |
HIP 89136 |
16.52 |
| 2026-10-02 12:00 |
18:11:51.14 |
-11:34:23.7 |
HIP 89136 |
16.81 |
| 2026-10-03 00:00 |
18:11:52.07 |
-11:34:37.4 |
HIP 89136 |
17.10 |
| 2026-10-03 12:00 |
18:11:53.03 |
-11:34:51.0 |
HIP 89136 |
17.40 |
| 2026-10-04 00:00 |
18:11:54.02 |
-11:35:04.6 |
HIP 89136 |
17.69 |
| 2026-10-04 12:00 |
18:11:55.04 |
-11:35:18.2 |
HIP 89136 |
18.00 |
| 2026-10-05 00:00 |
18:11:56.10 |
-11:35:31.7 |
HIP 89136 |
18.30 |
| 2026-10-05 12:00 |
18:11:57.19 |
-11:35:45.2 |
HIP 89136 |
18.61 |
| 2026-10-06 00:00 |
18:11:58.30 |
-11:35:58.6 |
HIP 89136 |
18.92 |
| 2026-10-06 12:00 |
18:11:59.46 |
-11:36:12.1 |
HIP 89136 |
19.24 |
| 2026-10-07 00:00 |
18:12:00.64 |
-11:36:25.4 |
HIP 89136 |
19.56 |
| 2026-10-07 12:00 |
18:12:01.86 |
-11:36:38.8 |
HIP 89136 |
19.89 |
| 2026-10-08 00:00 |
18:12:03.10 |
-11:36:52.1 |
HIP 89136 |
20.22 |
| 2026-10-08 12:00 |
18:12:04.38 |
-11:37:05.4 |
HIP 89136 |
20.55 |
| 2026-10-09 00:00 |
18:12:05.69 |
-11:37:18.6 |
HIP 89136 |
20.89 |
| 2026-10-09 12:00 |
18:12:07.04 |
-11:37:31.8 |
HIP 89136 |
21.23 |
| 2026-10-10 00:00 |
18:12:08.41 |
-11:37:45.0 |
HIP 89136 |
21.58 |
| 2026-10-10 12:00 |
18:12:09.82 |
-11:37:58.1 |
HIP 89136 |
21.93 |
| 2026-10-11 00:00 |
18:12:11.25 |
-11:38:11.1 |
HIP 89136 |
22.29 |